classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: Rockburner on April 11, 2023, 12:27:31 PM
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I've inherited my father's JAP engined, Featherbed framed 'special', and I'm trying to get it setup for road-riding, it's registered and has been used in the past for road-riding and display events (eg Kop Hill), but since he died in 2021, it hasn't been used (in fact it wasn't used much before then), and I'm struggling to get it running right.
The engine is a a ~400cc* JAP 4-stud motor, with a Cooper ally small fin barrel (ie, from a Cooper race car), running an AMAL Monobloc, and a BTH Magneto.
Frame is a Slimline Norton Featherbed.
Gearbox is a 1950s Norton 4-speed.
Akront wheels, brakes are Grimeca 4-ls front, Norton rear.
So far I've got it 'running' after cleaning out the Monobloc carb and reassembling.
It starts easily and fires up fine - in the workshop**. Previous to cleaning up the carb it wouldn't tick over, now it ticks over fine and responds to revving fine when on the stands.
However - I've taken it out on the road (round the block) a couple of times, and it always does the same thing: It'll run fine for a couple of minutes - up through the gears to about 60mph or so, a couple of times, but then, within 5 minutes of starting, the power just dies away completely and it'll barely run, although it does seem to be able to tickover still.
I thought it might be running rich, so I lowered the needle in the carb (to the lowest option, from the 2nd lowest option), and that didn't seem to make much difference - although it did seem a little 'weak' at full throttle - so I'm slightly concerned I've gone too far the other way and made it lean, OR the problem is something else completely. It goes to full throttle very easily: fitted witha Tomaselli Quick Action twist-grip - only about 1/4 turn from closed to WOT.
The first time I took it out, and it started playing up, the plug came out very black and oily (but dry).
Then I checked it two days later prior to my second test-run, and the plug was actually wet with oil.
After the 2nd test-run, the plug was again black and oily, but dry (ie not sooty black, but oily black).
The engine is also pushing about twice as much oil to the head as it should - I've read (somewhere) that the Pilgrim pump should be pushing oil to the head at a rate of 1 drop every 5 seconds at tickover. Currently it's running about 2 drops every 5 seconds, so I'm going to adjust that, but before I do - would running R30 instead of R40 be the cause of a doubling in the oil feed rate? IIRC Dad ran it on R40, but I was adviced that R30 might be better during the cooler days at present (and switch to R40 during high summer or for faster riding).
The worry I now have is that oil seemed to be getting into the combustion chamber - would that indicate a leak from a valve-stem? I'm not even sure if these motors run valve-stem-seals (in the modern sense), or could it just be the 'over-oilling' overwhelming the valve-stem?
Very grateful for any advice that anyone can give!
(https://live.staticflickr.com/65535/52801072462_8604e158db_z.jpg)
* It's a mix of 500 and 350 parts which come out at around 400cc.
** Starts fine sitting on a paddock stand.... pull the bike out into the fresh air and it takes 10-15 kicks.... could this be due to the fact that I'm starting it on an angle? on the paddock stand it's pointing slightly 'downwards' (rear wheel is raised a couple of inches), but outside the uneven ground means it's leaning 'backwards' slightly (pointing 'upwards', rear wheel is a couple of inches below front) ???
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I've found monoblocks can cause difficult starting when on side stand. One of my bikes is a pig on the side stand but stand it upright and it's fine. Isn't that one of the reasons Amal went to the concentric carb ?
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That it runs fine when it goes vindicates the carb set up. That it plays up hot suggests the magneto. An open circuit within the mag windings arcs to form a carbon track. This is of low resistance when cold, but high resistance once it warms up, reducing magneto output.
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Hi
Have you checked the fuel tank vent? / fuel tap flow, it sounds as though it is running out of fuel after 5 min but still enough flows to keep it ticking over ?
John
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That it runs fine when it goes vindicates the carb set up. That it plays up hot suggests the magneto. An open circuit within the mag windings arcs to form a carbon track. This is of low resistance when cold, but high resistance once it warms up, reducing magneto output.
Hmm - yes - that could be the issue, I've seen it before (we had a Comet that would do that - it would run fine when running, but if it stalled then you had to wait for it to cool down before it would fire again! Very annoying if you stalled it on a long rideout!).
What's the best way to test this??
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Hi
Have you checked the fuel tank vent? / fuel tap flow, it sounds as though it is running out of fuel after 5 min but still enough flows to keep it ticking over ?
John
Good thought - I'll check that as well.
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I've found monoblocks can cause difficult starting when on side stand. One of my bikes is a pig on the side stand but stand it upright and it's fine. Isn't that one of the reasons Amal went to the concentric carb ?
Just on this point - when kicking the bike outside, it was upright, not on the side-stand, although I suppose it be leaning slightly when I kick, but not much.
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What's the best way to test this??
Take it on a long rideout - and see if it will restart hot !
I'm going to add that this often indicates a problem with the condensor.
Buried within the armature windings, on many magneto types.
Starts easily when cold, difficult or utterly refuses to start when hot.
The opposite with bad or failing wiring really.
Some such ailments can be cured with those little Brightspark Easycaps,
as a condensor replacement. For some magneto types.
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If you look at a monobloc - or the earlier 276 type - you'll see why starting on the prop stand can be problematic. The level of petrol seen at the jets will drop as the float chamber is on the left of the carb thus weakening the mixture.
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What's the best way to test this??
Take it on a long rideout - and see if it will restart hot !
i would if it ran for more than 3 minutes!
I'm going to add that this often indicates a problem with the condensor.
Buried within the armature windings, on many magneto types.
Starts easily when cold, difficult or utterly refuses to start when hot.
The opposite with bad or failing wiring really.
Some such ailments can be cured with those little Brightspark Easycaps,
as a condensor replacement. For some magneto types.
I'm looking into people for that now
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In the same vein as blocked petrol tank breather, it's worth checking that you still have tappet clearance as the motor warms up.
Leon
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Are you sure the carb isnt worn out........I had similar trouble with an Ariel,the monobloc had been fitted new,but the slide was completely worn out ,as was the slide bore.......monoblocs had a bad name for being rubbish alloy,but then so did concentrics.
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Hi
Have you checked the fuel tank vent? / fuel tap flow, it sounds as though it is running out of fuel after 5 min but still enough flows to keep it ticking over ?
John
Fuel flow looks ok to me:
https://youtu.be/7I_E-CXGeMY
And now I need more fibre washers: the brand new one from Burlen has gone hard already and won't seal. Might try making one out of Viton....
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Hi,
I would run the flow test for at least 5 min or as long time wise to simulate when the trouble happens ??
John
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Hi,
I would run the flow test for at least 5 min or as long time wise to simulate when the trouble happens ??
John
I've got to replace the seal anyway so I'll have another go.
But pretty sure it's fine.
The filler cap is Monza type and i stripped it to check the breather bikes and they were fine.
I'm going to get the Mag rewound so will be stripping the bike down. But irritating as i was hoping to be riding it this summer.
Dies anyone have a link that explains how to setup timing and contacts for someone who's never seen a cintact breaker before? I've never done it and never seen it done. :(
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Try this http://classicmotorcycleforum.com/index.php?topic=6299.msg31348#msg31348
It didn't work for the person who needed it...
Leon
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A failing mag coil needs to get hot before causing problems.......typically this takes 1/2 hour running.............while one of the film capacitors (and remagnetizing) will improve a failing mag,it will also accelerate its demise with the higher voltage in the coil.
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A failing mag coil needs to get hot before causing problems.......typically this takes 1/2 hour running.............while one of the film capacitors (and remagnetizing) will improve a failing mag,it will also accelerate its demise with the higher voltage in the coil.
It's a fair point. Can you suggest any other cause for the bike dying after 5 minutes? I'm pretty sure it's not fuel flow, but will be checking that again.
What other causes might there be for a JAP engine to die after 5 minutes of running?
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Some things are easy to check. Just lift the fuel cap after a few minutes and you'll know it's not that. Check the tappet clearance when the bike stops - you need some. Check that the valves aren't tightening in the guides at things warm up, and so not closing properly - check that there is some compression immediately the bike stops. Beyond that, maybe the magneto is tired.
Leon
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Checked the fuel flow again last night, it's fine.
Also pulled the rocker cover off and rotated the engine using the kickstart (not ideal), but with that cursory inspection, it looks like the inlet valve has closed up completely.
Hopefully it's just the gap closed up and it's not a case of getting the valve seats redone. I think the head has already had phosphor-bronze seats put in, but not sure.
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From what you say it hasn't run much so I doubt whether valve seat recession is the problem. Either the clearance was incorrect from the start or has somehow tightened up - although they usually slacken rather than tighten. Are you sure you're checking at the right point?
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From what you say it hasn't run much so I doubt whether valve seat recession is the problem. Either the clearance was incorrect from the start or has somehow tightened up - although they usually slacken rather than tighten. Are you sure you're checking at the right point?
Not yet!
Need to get the chain case off to rotate the engine properly, and then expose the valves fully to see what's going on
I also need to find a clearance measurement.
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Need to get the chain case off to rotate the engine properly, and then expose the valves fully to see what's going on
Just remove the spark plug, put it in gear and either rotate the back wheel or wheel it
along the floor to get the engine to where the valves are closed.
You'd probably want to be seeing 5 or 6 thou.
But don't quote me on that, or hold me to it.
I haven't seen your engine...
Much less than that is likely to be a problem though.
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If you do as suggested by R and use a pencil or such through the plug hole you'll find that there are 2 top dead centres. One of these should have a clearance on both valves (the end of the compression stroke), the other should have no clearance (end of the exhaust stroke). Make sure you're checking on the right one.
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If you do as suggested by R and use a pencil or such through the plug hole you'll find that there are 2 top dead centres. One of these should have a clearance on both valves (the end of the compression stroke), the other should have no clearance (end of the exhaust stroke). Make sure you're checking on the right one.
Yes - I know how to do valve clearances, ;) (been doing them on my 1150 BMW for 20 years)
I just didn't know 'where' on the JAP engine the clearance was measured, or what the clearances should be. I also don't know if there's paper gaskets that need to be bought first before I dive in.
Luckily I've got a copy of "The Book of the JAP Engine", and I've now found the info I need. Apparantly the clearances are 0.002" when cold, measured directly between the tappet and the valve-stem.
Which is what I expected, kinda, but I was confused by the multiple covers over the valve-gear: it would have made sense to me if the measurement was made somewhere in the rocker box because then it's 1 cover to remove and reseal, rather than 3 (or more).
I'm also slightly concerned about re-sealing the covers, the rocker cover contains 2 'bosses', which act on the rocker end-faces to maintain the 'end-float'. So adding a gasket of some sort would affect that end-float. (the rocker cover plate is also cracked, which doesn't make me happy either!)
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It's one thing that a particular JAP engine needed 2 thou of tappet clearance, another to know what is required in a hybrid engine made from an unknown collection of bits half a century on. Who knows what the push rods are made of? The key thing relevant to your problem is that there is some valve clearance when the engine stops running. When the engine stops stand on the kick start lever and see if the compression is still there.
Leon
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It's one thing that a particular JAP engine needed 2 thou of tappet clearance, another to know what is required in a hybrid engine made from an unknown collection of bits half a century on. Who knows what the push rods are made of? The key thing relevant to your problem is that there is some valve clearance when the engine stops running. When the engine stops stand on the kick start lever and see if the compression is still there.
Leon
There's definitely compression. If anything I think the exhaust valve clearance has come loose. There was a lot more movement on it when I made my cursory check than there was on the inlet.
You're right of course that it's a 'made-up' engine, but I've found some notations made in my father's inimical manner within the books that make me pretty confident that this was what he understood to be 'right' for the engine.
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If its a cast iron engine,then inlet just free and exhaust at 002 will be correct...........I wouldnt assume anything drastic has happened ,but concentrate on the faults likely to develop with out of use .......Fuel and magneto.......The symptoms sound like fuel ........check the monobloc float valve ....there is a small spacer on the float spindle sometimes left out.....or maybe the needle valve is blocking fuel flow ........this was a fault with the nylon ones ..........if thats OK for sure ....then Id take off the mag chain,spin it and see if it has a fat blue spark.........any trace of red spark will be condenser problem from moisture pickup.
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If its a cast iron engine,then inlet just free and exhaust at 002 will be correct...........I wouldnt assume anything drastic has happened ,but concentrate on the faults likely to develop with out of use .......Fuel and magneto.......The symptoms sound like fuel ........check the monobloc float valve ....there is a small spacer on the float spindle sometimes left out.....or maybe the needle valve is blocking fuel flow ........this was a fault with the nylon ones ..........if thats OK for sure ....then Id take off the mag chain,spin it and see if it has a fat blue spark.........any trace of red spark will be condenser problem from moisture pickup.
To the best of my knowledge, the engine is predominantly standard JAP parts, apart from the alloy barrel (as used in Cooper race-cars).
I've done everything I can with the carb, it flows fuel fine, but might be jetted or set slightly off - I'm not sure how to check it further because I can't currently run the engine for more than 5 minutes (ie to get it hot), because it loses all power and will barely run at that point. Hence moving on to things like valves and timings.
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May we enquire what spark plug it currently has in it ?
(you have tried a NEW plug, haven't you ?)
The wrong heat range may see the plug overheat OR be too cold to keep running,
even in those few minutes.
A bit unlikely, given how general purpose plug types of old were, but you don't know until you try it ...
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Hi R,
There is no need to pull off all the valve covers to check the tappets
Just make sure there is a little movement at the pushrod adjusters, pushrod free to rotate and a smidgin more on the exhaust side.
No gasket needed on the inspection cover, a light smear of Hylomar if you must
John
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Not my bike John !
My JAP is of the sidevalve persuasion.
You can SEE the valve clearances !
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May we enquire what spark plug it currently has in it ?
(you have tried a NEW plug, haven't you ?)
The wrong heat range may see the plug overheat OR be too cold to keep running,
even in those few minutes.
A bit unlikely, given how general purpose plug types of old were, but you don't know until you try it ...
It's a Champion L86C. From I've found to read online about the plug itself, it seems about right.
But a new one is a good idea. I meant to order one a week or so ago and forgot, Thanks for the reminder!
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Hi,
Sorry R I was abbreviating Rockburner ::)
John
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Heyhey, I resemble that remark .........
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Hi,
Sorry R I was abbreviating Rockburner ::)
John
I've been called worse..... :D
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What sort of compression should i be getting?
I realise that it's a hard question to answer given that the engine is a bitsa with 350 and 500 internals rounding out to about 400cc, but any educated guesses would be appreciated.
Currently getting about 75psi.
https://flic.kr/p/2ozWQPH
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Compressions are ALWAYS tested hot, with the throttle wide open.
Otherwise the results are a little haphazard.
Any idea/inkling of the compression ratio ?
75psi seems a little low - for a healthy ohv hotrod. ?
Tipping a teaspoonful of oil down the plughole, kicking over a few times and retesting is advised.
If the number jumps upwards, then the ring seal is not so good.
Either new rings or more running in is required.
Or testing hot, with that throttle wide open ...
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So, some health issues have kept me out of the garage recently, but recovery is under way.
I've checked the valve clearances and they seem to be ok, ie there is play at tdc on both rockers when cold!
I've ultrasonicly cleaned the Monobloc and reassembled it with the upgraded Viton tipped float needle and the rest of the refurb kit from Burlen.
I stuck some petrol in the tank and opened the taps.
No leaks was the first win!
I tickled it up but instead of fuel coming out of the tickler, it eventually started dribbling from the manifold, bit odd, but the fuel is flowing.
Kicked it a few times and eventually it fired up, bit rough at tickover, but some small adjustments fixed that.
Opening the throttle though and there's a lot of spitting and backfiring, flames from the open bell mouth. Not good. I'm now worried that the inlet valve isn't shutting correctly, with the throttle fully open you can look down the manifold and see the flame front!
Nevertheless I took some time to adjust the oil feed to the head which wasn't running, now running at (roughly) a drop every 5 seconds on tickover, just like the book says.
I'm going to try a smaller main jet in case it's just a case of over-fuelling, but if it's still backfiring I'm going to have to have another look at the valves.
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The main jet doesn't come into play until the throttle is more than about 3/4 open,
so you can probably omit that step.
Dropping the needle a notch would achieve less fuelling, at lower engine speeds.
It does sound more like cam timing though.
Unless the inlet valve isn't seating too well ??
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I have never understood why the Amal tuning procedure starts with the main jet, which as you say isn't used until wide open throttle. I always start with a main jet I know to be too big and go through the process of setting up idle mixture screw, cutaway and needle in that order before even considering main jet.
People wlays talk about increasing main jet size when they fit a less restrictive exhaust system but unless they go everywhere with the twistgrip on the stop - and by the sound of it many do round here - that seems a bit pointless to me.
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The main jet doesn't come into play until the throttle is more than about 3/4 open,
so you can probably omit that step.
Dropping the needle a notch would achieve less fuelling, at lower engine speeds.
It does sound more like cam timing though.
Unless the inlet valve isn't seating too well ??
Good point about the needle - I"ll try that (not sure what it's on at the moment tbh)
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It appears to be a race bike ,so its going to have a pretty radical cam in it..........this may make it hard to check the valve timing ..........and spitting back at slow revs may be a side effect of very early inlet opening.
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It appears to be a race bike ,so its going to have a pretty radical cam in it..........this may make it hard to check the valve timing ..........and spitting back at slow revs may be a side effect of very early inlet opening.
Its a fair point, I've no idea what cam is in there. Just looking in the cam bix is an engineer out of the frame job (i think), and knowing my Dad, it may well have a "hot" cam.
What can be done to alleviate that situation?
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What kind of motor is it..........I assume its a 4B or similar .....in which case someone like Cameron Engineering will be able to supply a milder cam......at a price,mind you.
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What carb is it ......the pic seems to indicate a Type 27 speedway carb ,or maybe a 10TT
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What kind of motor is it..........I assume its a 4B or similar .....in which case someone like Cameron Engineering will be able to supply a milder cam......at a price,mind you.
It's a 4-stud, with a Cooper barrel (lightweight, small fins), and the internals are a mix of 350 and 500 that equate to 400cc (approx). I keep forgetting how Dad actually managed that.
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What carb is it ......the pic seems to indicate a Type 27 speedway carb ,or maybe a 10TT
Amal Monobloc 389.
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I tinkered with the JAPton last night. (Life is busy at the moment, so I don't often get into the workshop).
It's all back together but wasn't running properly - lots of spitting back and backfiring in the exhaust.
Got it running, and spent about an hour going back and forth between the ancient Monobloc "Notes" leaflet (Dad had some photocopies so at least I wasn't getting the original filthy!)* Eventually got my head around it and realised that the damn thing was running "weak" in the mid-range and so pulled the needle up a notch (the first thing I'd done was lower it a notch to the "top" notch, it refused to run on that setting). Now it's in the middle of the needle's range its actually running pretty well (once it's hot). The occasional spit back or backfire, but I think I can live with that for now.
Happy bunny!
During the course of the session I'd spotted a couple of nuts that had fallen on the floor - one was an engine bolt that (in hindsight) I know was loose - the primary chase mounting lug is held in place by it and I'd simply forgotten it was loose.
The other was the nut off the forward connection for the gear linkage.... it's a nyloc, but I discovered that Dad had cut the bolt for it down so short that the threads aren't actually engaging the nylon locking collar! ( ffs). Couldn't be arsed at that point to root around for a better bolt so I just pushed the nut on upside down. Hardly ideal but it'll do to hold it all together while I figure out another issue.
I was wiping some oil off the top of the crankcase when I discovered something that terrifies me...
(https://live.staticflickr.com/65535/53099362614_00d00c9d8f_z.jpg)
That bolt, the one between the push-rod tubes, is loose, and it won't go tight. :o
It just revolves.
Now - I may be wrong.... but, to me, that indicates that there's a friggin NUT on the other side of the case, that is loose, and is hanging on the threads of the bolt.
I may be wrong, and the loose bolt is caused by the threads on either the bolt or the casing being thoroughly knackered.
But - either way, the mininum work needed before I can do anything with the bike is to strip the entire right side of the engine away to check what's going on in the timing box. :roll:
I can't take a chance on the probability of a nut dropping into the timing box.
So - The JAPton is unlikely to see tarmac again this side of Easter, simply because I know that I've never done any of this stuff before and I'll be taking things very slow and thoroughly checking it all, and researching how it all works. Oddly, for all the tinkering I've done over the years, this is the first time I've ever had to actually do the timing on anything.
I also seem to have been thrown off / barred from the JAP Engine Facebook group I was on - so also need to find a J.A.P. specialist source of further information.
Dagnabbit.
* I must get a copy of that leaflet blown up and laminated. I did the same with the exploded diagram for the carb and it's an invaluable reference sheet).
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Most likely the thread in the crankcase is stripped. I think it unlikely there's a nut underneath. Getting the head & barrel off will only take half an hour or so.
Re the spitting back - I had a similar problem with my ES2 fitted with a monobloc and found that a richer slide cutaway (lower number) sorted it out, as the cutaway controls the mixture on transition between idle and the point that the needle jet takes over. The slide was kindly donated by someone on here but sadly I can't remember who.
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Most likely the thread in the crankcase is stripped. I think it unlikely there's a nut underneath. Getting the head & barrel off will only take half an hour or so.
Re the spitting back - I had a similar problem with my ES2 fitted with a monobloc and found that a richer slide cutaway (lower number) sorted it out, as the cutaway controls the mixture on transition between idle and the point that the needle jet takes over. The slide was kindly donated by someone on here but sadly I can't remember who.
I "believe" that I need to get into the timing chest, rather than the crank case volume itself - so need to get the timing apparatus off the rhs, rather than the head and barrel off, but need to find some internal schematics first to check that.
It looks to me like the pushrods are actuated by the cam-followers in a side-chest.
(https://live.staticflickr.com/65535/53099753484_77ea83342b_z.jpg)
Would be seriously useful to have a 2nd engine to play with and see where everything goes!
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Yes, it's just like 99% of old motorcycle engines.
I don't know what the problem bolt does: I assume that holding the head and cylinder down is left to the four main studs, which are suitably symmetric, in which case is the problem bolt just filling a hole used for an oil inlet or breather? If it turns, what happens if you turn it and pull it up? There is no way it has a nut underneath inside the timing chest.
Leon
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I'm with Leon.
Although I no longer have a JAP engine, I'm sure that there is no actual function from a bolt there between the pushrods. I suspect that it is a breather someone has added at some point, and that brass "bolt" is actually a plug. As Leon suggests, try lifting and un-doing it; it will probably screw out to reveal an ill-fitting plug.
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Yeah - that's the first thing I'm going to try when I'm next in the workshop. The engine was very hot when I first observed the issue so I was struggling to get at the thing!
I seriously hope that there isn't a nut underneath it... but knowing my Dad..... there's a possibility....
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oh yeah - there's one other weird thing...happening:
On the Monobloc carb, although I've cleaned it all up, when I use the tickler to push the float down, it "works" - but the fuel doesn't overflow through the ticker - it eventually overflows out of the bellmouth! (or possibly a tiny hole in the inlet manifold).
The tickler is imply a metal tube, closed at the top end, but with a small hole on the side about a mm down from the top. The bottom of the tube is squared off, but not closed up, and it's completely clean - it's not blocked in anyway.
The top of the float - which the tickler pushes down on, is rounded, so there's no "flat plane" on which the end of the tickler could possibly "seal".
So I'm highly confused as to why the fuel isn't exiting out of the tickler!
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Managed to unscrew the bolt this evening.
The threads on both the bolt and the case are "tired". But i found a bolt in my grab bag of Imperial bolts that actually screws in and will go "tight".
https://flic.kr/p/2oUxRsd
https://flic.kr/p/2oUwLGC
Old bolt on left....
So I'm going to cut it a bit shorter (both bolts are twice as long as they need to be), and smother the top end of the threads with silicon and put it in with an ally crush washer (unless i can find a suitable fibre, but i detest fibre washers).
Before that though, I'm going to stuff an endoscope into the hole!
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Ive sort of wanted a copy of "The JAP Engine " by Fenner for years ,but never going to pay a silly price .........then I just happened to see an as new copy with the red dust cover intact for $10 at a flea market .........anyhoo,this book includes a section by Wal Phillips on the speedway engines .........and thats where the photo of the timing gear comes from .
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Ive sort of wanted a copy of "The JAP Engine " by Fenner for years ,but never going to pay a silly price .........then I just happened to see an as new copy with the red dust cover intact for $10 at a flea market .........anyhoo,this book includes a section by Wal Phillips on the speedway engines .........and thats where the photo of the timing gear comes from .
Wow! That's an excellent find!
I have both the Fenner, and 2 copies of the Pitman "The Book of the J.A.P. Engine" (2nd and 3rd editions). My Dad always like to check the definitive sources as much as he could. The problem is that I think a lot of his notations were for his other J.A.P engined bike... a 1930 HRD Vincent, which had an earlier J.A.P. engine in it, than the one in the special I've got.
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last week I "fixed" the hole in the JAPtons crank cases (timing chest actually).
I did stick an endoscope down it, but there wasn't a lot to see!
I cut down the new bolt so that it was roughly the length required to fill the cases, with a crush washer on top:
(https://live.staticflickr.com/65535/53124941883_658a497e38_z.jpg)
Then fitted it in with a good amount of Soudall Fix-All smeared into the threads and around the crushwasher and head. With any luck that will act as a seal and thread-lock even though the bolt isn't done up that tight. I tried very hard NOT to strip the threads so only did it up as tight as I dared....
(https://live.staticflickr.com/65535/53123859002_d901c0f550_z.jpg)
Obviously will be keeping an eye on it, but I can't move it with my fingers... so it's an improvement
I had an idea that the issue with the carb tickler might have been the paper gasket between the jet block and the main body (the surfaces this gasket mates to are not the smoothest....). So I stripped the carb down and put a small amount of blue-hylomar on each face of the gasket and reassembled it.
No difference. Whatever is preventing the tickler working correctly is still evading me. Next attempt will mean going into the float bowl itself and seeing there's something odd about the interface between the tickler and the float. I've been doing some reading up and it seems that the new nylon floats sometimes cause minor problems so it's worth taking a look.
(https://live.staticflickr.com/65535/53125829705_e846708bb1_z.jpg)
Took the JAPton out for a spin round the block this evening.
It might run ok at less than 1/4 throttle, but any more than that and it starts bogging down, won't fire at all, then after 2 or 3 deafening explosions from the exhaust it'll pick up and run well for about 10 seconds before it starts bogging down again.
Rinse and repeat again and again if I try to ride it anything more than 1/4 throttle (ish).
And obviously it's still pissing oil....
(https://live.staticflickr.com/65535/53124831057_0cc94bcab7_z.jpg)
(https://live.staticflickr.com/65535/53125910768_8dc89ff773_z.jpg)
So... Back to to the tuning leaflets....
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I wonder if the bolt should be a breather? Earlier JAPs were very clever in how their engines breathed, and the timing chest was vented directly to the atmosphere. Oil will be forced out randomly if there is no method to relieve excess pressure from the cases/timing chest. I know all about the early engines (where venting the crankcase will cause the entire oiling system to fail), but unfortunately I don't know the details of the later oiling systems, other than to say "be careful of what you vent and what you don't".
Leon
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JAPs traditionally breathe only through the oilbox ......if you put breathers anywhere else ,you upset the lubrication system,and may even cut off the big end feed
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No difference. Whatever is preventing the tickler working correctly is still evading me. Next attempt will mean going into the float bowl itself and seeing there's something odd about the interface between the tickler and the float. I've been doing some reading up and it seems that the new nylon floats sometimes cause minor problems so it's worth taking a look.
I seem to recall that the tickler on Monoblocs can be "adjusted" slightly by tapping the central tube down or up in the carb body. Maybe the current position is too high for juice to appear at the tickler before it drips from the carb itself?
Or maybe I'm thinking of another carb... ???
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JAPs traditionally breathe only through the oilbox ......if you put breathers anywhere else ,you upset the lubrication system,and may even cut off the big end feed
That's pretty much my understanding too.
This bike "has" run well in the past, but was parked up for a few years (my Dad's health deteriorated and he died in '21, it took me a year or two to be ready for looking after the bike).
Last Friday I Took the JAPton out for a spin round the block:
It might run ok at less than 1/4 throttle, but any more than that and it starts bogging down, won't fire at all, then after 2 or 3 deafening explosions from the exhaust it'll pick up and run well for about 10 seconds or so before it starts bogging down again.
Rinse and repeat again and again if I try to ride it anything more than 1/4 throttle (ish).
I've been pouring over the literature I've got (the JAP books, and the AMAL tuning leaflet) and I still can't get my head around whether these symptoms are the carb set too rich, too weak, or something else completely.
The Amal booklet seems to suggest that issues with firing in the exhaust are ignition related.... But that doesn't balance with the fact that the engine WILL run properly for a few seconds before it bogs again, so I'm somewhat confused.
As I say, it'll run ok for a bit, then it seems as if something "builds up" and it stops firing, until the fuel in the exhaust detonates, and it clears up and runs again.... Until the "blockage" builds up again. That's what makes me think it's not ignition or timing - because presumably it wouldn't run at all at lower throttle openings etc if the timing had shifted?
Next thing I'm going to do is go over the inlet manifold and exhaust joins and check there's not gaps or holes in the system.
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Well, I've still not figured out what's wrong with the JAPton. Did some checks last week and fuel flow is good ( more than half a litre per minute, which ought to be fine).
Raised the needle by one because i thought it might be a bit weak, and tried starting it up and although it started easily enough, its still spitting back and backfiring.
I'm beginning to think the ignition timing has slipped, so i took a cover over the magneto drive sprocket to check it.
Seemed fine so went to put the little cover back on, and bugger me if the sodding thread didn't strip.
GAH!
So I'm going to put the JAPton aside for a bit and concentrate on the other projects i need to get done before winter, and will very likely spend the winter stripping the thing down and learning more of its foibles.
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That'll be fun.....
I am considering a Chinese pitbike carb for my Tri-Greeves. I have the correct monobloc but it's missing bits and is in poor shape. For £15 must be worth a punt......
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Have you tried tickling it while its running.
The amal, the amal.
(Not while riding it either.)(could be a risk to life and linb)
If its fuel related, this should tell if its starving for fuel.
There is some chat about viton tipped fuel needles, or not, in monoblocs.
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The obvious answer is to fit another carb that is known to work OK.
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There is some chat about viton tipped fuel needles, or not, in monoblocs.
Yep, some claim that the Viton needles are prone to sticking "up" and shutting the supply of juice off.
Re the pit bike Choagy carbs, an old boy I know paid £14 for one off Ebay, and stuck it on his reluctant Tiger Cub. Apparently it started second kick and even ticks over fresh out the box.
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The obvious answer is to fit another carb that is known to work OK.
Its certainty a thought.
Do you have one to lend? ;)
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There is some chat about viton tipped fuel needles, or not, in monoblocs.
Yep, some claim that the Viton needles are prone to sticking "up" and shutting the supply of juice off.
Re the pit bike Choagy carbs, an old boy I know paid £14 for one off Ebay, and stuck it on his reluctant Tiger Cub. Apparently it started second kick and even ticks over fresh out the box.
I've heard this myself which is why I'm considering it. Ebay also has sets of main & idle jets for a couple of quid or so. I've never had the experience if viton needles sticking despite using them for decades.
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There is some chat about viton tipped fuel needles, or not, in monoblocs.
Yep, some claim that the Viton needles are prone to sticking "up" and shutting the supply of juice off.
Re the pit bike Choagy carbs, an old boy I know paid £14 for one off Ebay, and stuck it on his reluctant Tiger Cub. Apparently it started second kick and even ticks over fresh out the box.
I've heard this myself which is why I'm considering it. Ebay also has sets of main & idle jets for a couple of quid or so. I've never had the experience if viton needles sticking despite using them for decades.
Got any links for the jets?
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https://www.ebay.co.uk/itm/404463872342
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Yes ,im tossing up whether to get a 28mm RE carb ,which will be jetted correctly ,or a cheapy PWK a bit bigger ...maybe 30mm.........from what Im told ,if the cheapy isnt jetted right ...or at all......buying bigger jets is a no go ,and the jets are different thread from mainstream carbs that the Chinese ones are copied from.
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I've bitten the bullet and ordered a 20mm device (equivalent to the standard 3TA monobloc). I'm emboldened by the fact I just bought a complete CDI / coil package for my Honda XBR500 and it seems to work as well as the Dutch one I paid £110 for. How much for the ebay item? £10.56. And it arrived today after ordering on Sunday......
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Just seen a very tidy 1971 Triumph Daytona with a few bits missing (mufflers ,covers ,speedo/tach) go for $5000..........reckon some dealers will be sweating a bit............see some auction results from UK too .......owners here asking $20k + for Velo Venoms far of the mark.....UK auction sales of tidy Velos and Gold Stars around $10k A.
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I've just seen on a F-B group I'm on a tidy running Venom in the unusual red and black colour scheme on sale at £5750. No idea how that relates to Oz dollars but I'll bet it's less than 10k's worth.
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A bit over $10k on todays rate......the card co gave me 49 p when I bought the valves .........anyhoo,you wont find any kind of 500 Velocette here under $25k (12k GBP).........there is a 350 AJS on ebay now with a start of $16k/8000GBP.....and no ,its not a 7R.
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.there is a 350 AJS on ebay now with a start of $16k/8000GBP.....and no ,its not a 7R.
Imported from the UK. !
That alone would have cost him an arm and a leg.
The "1938" Norton there for $25k would take some beating. ?
The days of pirates about may not be be over....
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You should check out the results achieved for old British bangers in the latest Shannons sale that finished a week ago.
Lot 108, 1950 Matchless G80, $7,200. Lot 109, 1953 Matchless G9 500cc twin, $5,100. Lot 115, 1952 Triumph Thunderbird,$14,500. Lot 116, 1953 Ariel Square Four$17,000. Lot 121 Triumph X-75 Hurricane, $40,500.
The other eight Brit bikes didn’t sell
Those are actual sale prices, not eBay dreamer stuff. $16,000 for a 350 Ajay! Tell’im ‘e’s dreamin’.
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Anyone know what Shannons sellers comission is? ...........have to be at least 10% ,Id imagine ,possibly more .
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To carry on the Saga....
I've been tinkering with the bike recently and reduced the size of the main jet down 1 size. This seems to have helped when WOT. I've a feeling that giving the carb a good sitz clean has affected some of the fuel pathways and they're now more open than they were - thus messing up the ratios.
I'm going to reduce the size of the needle jet next - to see if that helps the lower-throttle openings - obviously after seeing what the needle is doing.
However I may also be having electrical issues: I took the bike round the block and it ran fine at WOT, roughly at lower throttle, but after about 2 miles it just died a death and I couldn't get it to fire at all. The plug seemed nice and dry (and not sooted) when I pulled it out on the side of the road, so I don't know yet why it wasn't re-starting.
I also have the issue that the kickstarter splines seem to be going - no matter how tight I bolt up the kickstart lever I seem to able to twist the lever on the shaft after about 10 or so kicks. :( Fingers crossed it's just the splines on the lever, and not the shaft....
I'm also going to take a good look at the coil - see if it's still measuring the correct resistance.
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Might be time to file the slot on the kickstarter a little wider enabling the bolt to clamp more.
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Might be time to file the slot on the kickstarter a little wider enabling the bolt to clamp more.
I've done that already - the slot physically can't close up.
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(https://live.staticflickr.com/65535/53699366162_0f96e53e81_z.jpg)
I'd say that's more than tired.
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Desperation being the mother of invention, I have taken a triangular file and a hacksaw,
and worked on something similar until it had a (short ?) another life !
Be aware that the quality of steels is a major factor here.
Really good stuff is likely to be more responsive than something akin to butter.
I must say I have met both, so Good Luck ??
Finding someone with a suitable broach may (possibly) provide better results.
Bear in mind these don't grow on trees ...
Took me a wee while to orient the photo.
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Tread recutters were a common tool way back when, but in those days the tyre carcase was so stiff the bike stood up and rode with a flat tyre. Modern rubber is much more pliable but seems to rot quicker, as the three year old tyres on my car will attest.
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I assumed that was the spline (remains) on a kickstarter ?
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Looking again I'm sure you're right. I thought it was a poor pic of a perished tyre wall. ::)
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Eons ago,my boss' son had a Honda 350 with a knackered spline on the kichstart (if thats what the pics about) ...anyhoo they were going to weld it on ,however I dissuaded them from such a bodge ,and by simply drilling a hole that was more or less 1/2 and 1/2 ,and driving in a roll pin ,the k/s was persuaded to work properly again.
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A previous owner of my Norton ES2 did something similar and it seemed to work for them. I replaced the kickstart with a new one and it doesn't flap about.
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Knackered is knackered. No matter what little bodges you perform the need to replace the worn parts remains. It’s one thing to do a temporary repair to get home or until replacements are available but anything else just makes the bike a misery.
Do a proper job of it. New parts.
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Way back when these were just old bikes and things were done to eke out a little more life from them, the fix of drilling along the spline/kick starter interface and fitting a bolt, screw, roll pin whatever often featured in the "ten bob tips" columns.
Don't know that I'd want to damage old parts in this way now though. :'(
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Not strictly relevant ,but if you have a fine spine shaft and close down a matching spline with a clamped split ,the spline will eventually be sheared off as wear occurrs .............I used to see this quite often in a particular large truck steering ,where the sector shaft and drop arm were fine splined parallel,and eventually all the spline would disappear ...with noticable effects on the steering.
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Well - I finally got back into the forum after lots of trying. (Many thanks Admin!)
The JAPton is being stripped down because the magneto ran out of sparks, and the head decided to give up retaining compression.
Issues found so far :
Timing chain was a bit loose...
(https://live.staticflickr.com/65535/54386761799_182520e298_z.jpg)
I wonder why....
(https://live.staticflickr.com/65535/54428911545_30c78c189b_z.jpg)
Rocker arm end-float was somewhat wide....
(https://live.staticflickr.com/65535/54405577970_9348cac5db_z.jpg)
They were both like that
This is roughly where it should be :
(https://live.staticflickr.com/65535/54405381129_e2e2e8489e_z.jpg)
And the amount of movement has caused this damage to the oil galleries in the rocker box:
(https://live.staticflickr.com/65535/54404328467_14fc049c30_z.jpg)
The engine sprocket was a git to get off.
(https://live.staticflickr.com/65535/54421572317_9936009a63_z.jpg)
The barrel skirt is damaged... but given the complete lack of damage to the piston/conrod, and the age/history of the barrel, we've concluded that this is old damage (I'm going to split the cases anyway).
(https://live.staticflickr.com/65535/54410272419_286fb8a430_z.jpg)
Exhaust valve seat was knackered - you could see daylight through it!
(https://live.staticflickr.com/65535/54423565562_25de3f03de_z.jpg)
errrrr.
(https://live.staticflickr.com/65535/54428911310_7434979e3e_z.jpg)
Ah.
(https://live.staticflickr.com/65535/54427681002_99f466941a_z.jpg)
Well - that explains the highly unimpressive performance of the valve-lifter.
(https://live.staticflickr.com/65535/54428728344_a13585c58b_z.jpg)
Cam follower probably needs replacing:
(https://live.staticflickr.com/65535/54428781363_0ea069fa2e_z.jpg)
Next series of steps will be to continue the strip down so as to be able to check the main bearings (I'm not expecting issues, but I've been advised it's worth doing). I'm not sure I'm brave enough to split the crank itself though.
Need to find an engineering workshop to weld some ally to that rocker box and tidy up the oil gallery so the exhaust rocker actually gets oil.
Then buy a few parts (hopefully), if not try to find them in auto-jumbles ( :o ), and reassemble.
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Thats corrosion pitting..........I wouldnt worry about it .............I can say one thing for sure .....do not replace the rollers with ball bearings ...... disaster when the bearings break up and wreck the cams...........My motor has new rollers and cam ,as the 500 motors use the same parts as the rotary cultivator engines ,and I was lucky enough to find a stash of NOS engine parts
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Thats corrosion pitting..........I wouldnt worry about it .............I can say one thing for sure .....do not replace the rollers with ball bearings ...... disaster when the bearings break up and wreck the cams...........My motor has new rollers and cam ,as the 500 motors use the same parts as the rotary cultivator engines ,and I was lucky enough to find a stash of NOS engine parts
I was going to talk to Speedway Spares about the roller - they sell both the assembly, and the individual components, but I'm not sure how easy it is to disassemble, and reassemble the roller arm group.
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The roller axles are rivetted in ,and probably a press fit as well ..........Ive never replaced one......but a while ago ,someone was selling off a well known stash of new Harley parts ,and the set of 4 tappet rollers from a shovel were around $10 ,so I got some ......the Harley ones have needle rollers Ive got a V twin JAP with really bad rollers ,probably 1/8" of losseness .......it was running like that ...but needs to be fixed.
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One engine Ive worked on ,the roller tappets had only half an axle ,the other 1/2 of the space in the roller was taken up by a spring looked like a paperclip .....the lifter body had half a hole broached into it,so there was no chance the axle could turn in the lifter ........very reliable system for an engine that would do a million miles.
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Hi RB
On some J.A.P ohv's the rockers are held in place by cast on "pip's" on the outer cover. In your photos I can see the protrusions on the rockers that would sit against the cover pips.
It looks wrong when you take the cover off and the rockers can push /pull , but is fine when the outer cover is fitted
John
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Hi RB
On some J.A.P ohv's the rockers are held in place by cast on "pip's" on the outer cover. In your photos I can see the protrusions on the rockers that would sit against the cover pips.
It looks wrong when you take the cover off and the rockers can push /pull , but is fine when the outer cover is fitted
John
Yeah - it'll be something to be checked thoroughly when I reassemble the box. Which won't be happening until I get that damaged oil gallery fixed.
In the meantime: while I'm not rushing, I've not been idle either:
The following is a conglomeration of progress:
When you think you have a large spanner....
(https://live.staticflickr.com/65535/54408088071_8be9cdeb4c_z.jpg)
But you still end up needing something larger!
(https://live.staticflickr.com/65535/54407217262_f739793c5a_z.jpg)
That nut came undone far more easily then I was expecting, but the threads cleaned up nicely. The exhaust is nicely patinated with spilt Castrol R, so I'm not going to polish it, just clean it up.
Next job is either to get the head off, or pull the engine out of the bike, just not sure which to do first.
pulled the head off :
(https://live.staticflickr.com/65535/54410273824_69fcb4c5c2_z.jpg)
(https://live.staticflickr.com/65535/54410095561_3446e6fdc4_z.jpg)
(https://live.staticflickr.com/65535/54410095211_d81f6e3287_z.jpg)
(https://live.staticflickr.com/65535/54410095176_ce7da9bd22_z.jpg)
This was most of the oil that had overflowed into the fins on the head.
(https://live.staticflickr.com/65535/54409222387_9d37274283_z.jpg)
(https://live.staticflickr.com/65535/54410472320_1fdcebf263_z.jpg)
(https://live.staticflickr.com/65535/54410340523_1982267789_z.jpg)
These scores look nasty, but tbh, I think they're actually just superficial.
(https://live.staticflickr.com/65535/54410272839_a4b4f61305_z.jpg)
So i thought I'd pull the barrel as well.
(https://live.staticflickr.com/65535/54409221862_c31db0f4d9_z.jpg)
Nice polished con rod there...
(https://live.staticflickr.com/65535/54410471800_2619fd5acd_z.jpg)
Nasty lump taken out of the barrel skirt though. :(
Funnily enough, I have the oddest feeling I've seen this before... Maybe in a photo or something. I need to see if there's any photos of this in the paperwork I have.
(https://live.staticflickr.com/65535/54410272419_286fb8a430_z.jpg)
(https://live.staticflickr.com/65535/54410471585_8298241cc7_z.jpg)
Next job is to fit a plug, or bolt into the head, then fill it with water to check the valve seals.
Oh, and see if that barrel is useable....
Oh yeah - I took a quick video of the movement on the big-end.
https://youtu.be/3hB3lH5znKU?feature=shared
Not the steadiest of shots I'll admit - but hopefully you can see the movement left to right of the conrod.
This seems a lot to me..... but is it a lot for a an engine designed in the 1930s?
(https://live.staticflickr.com/65535/54410272419_286fb8a430_z.jpg)
Concerning this damage to the barrel skirt.....
I've chatted to one or two mates of my Dad today, and although no-one remembers anything about this.... we sort of agree that:
a) IF this damage had happened during the current "build" of the engine... then that damage would be apparent elsewhere: ie, the conrod would be dis-attached to the piston and in several pieces itself: it's not. and;
b) Using this barrel would be exactly the sort of thing my Dad would do, if he considered that the piston is unlikely to be affected and the barrel wasn't going to start cracking up any further.
I've got a boroscope (ish) somewhere around, so I'll have a poke around in the cases, but I think that the barrel will be useable, and the damage was from a previous useage: ie some racer (possible a Formula 500 car) blew the engine, caused the damage, but then discarded the barrel to scrap/sale. The damage is likely 50 years old.....
any road - next jobs are to continue stripping the engine, and figuring out how the hell to mount the timing disc onto the drive-side of the crankshaft so I can attempt to check the timing on the thing. I also want to get the drive sprocket off - but can't figure out how to lock the crank in one position (tbh - I'm not even sure if the drive-sprocket nut is right- or left-hand threaded....)
I figured out how to get the nut off the engine sprocket...
(https://live.staticflickr.com/65535/54421572977_f6f7e64496_z.jpg)
(https://live.staticflickr.com/65535/54421572317_9936009a63_z.jpg)
The jaws on this clamp fitted into the sprocket carrier splines perfectly.
(https://live.staticflickr.com/65535/54422618614_9d4d1bec80_z.jpg)
The nut came off with a LOT of torque required... because the $%^&&er was loc-tited.
Tidied up the edge on that barrel liner skirt. It's usable because the piston is on a short stroke length.
(https://live.staticflickr.com/65535/54422806905_2a503c578b_z.jpg)
I also had a long call with a lovely old feller who is a bit of a guru with these engines, and he definitely have me some good advice and warned me about some things I wasn't aware of.
It turns out the conrod in the engine is most likely an aluminium one, which is not as strong as the steel ones (obviously), and they haven't been made since the '70s, however, given that the engine is setup as a 400cc, running 9:1, on regular petrol, instead of 15:1 on meth... We reckon it should be okay for road use.
He also gave me some directions on the rocker box rebuild, and described how to do the valve timing using "split timing". Apparently he's never seen a JAP cam that was actually manufactured to the exact correct shape! :D
Oh yeah, and the valves need lapping...
https://youtu.be/qFme0sPGCp0?feature=shared
Especially the exhaust! :D
Stripped the valves out of the head tonight.
(https://live.staticflickr.com/65535/54424670418_2f3fe8dda4_z.jpg)
(https://live.staticflickr.com/65535/54424810050_a4e49bc750_z.jpg)
(https://live.staticflickr.com/65535/54423565722_aa0f75b7d7_z.jpg)
The inlet valve had a good seal. You can see the shiny ring around the head of the valve, that's indicative of a clean seal to the seat.
The odd broken/tired rings are the mica washer(s) that sit under the spring cup. I'm not sure about these. I don't know if this is multiple washers, or one washer that has delaminated. I know nothing about the material mica.
(https://live.staticflickr.com/65535/54424809865_3f3bfca36e_z.jpg)
The exhaust needed a little... "persuasion" ... to separate the collets from the spring cap.
(https://live.staticflickr.com/65535/54424420091_dfb58f9a8e_z.jpg)
You can see that the exhaust seat isn't shiny like the inlet.
(https://live.staticflickr.com/65535/54423565562_25de3f03de_z.jpg)
Lots of crud around the valve stem tube fitting on the exhaust side
(https://live.staticflickr.com/65535/54424809645_80a49a86ec_z.jpg)
Needs a clean
(https://live.staticflickr.com/65535/54424669873_b00c79f8f1_z.jpg)
And, guess what.....
There's a video too! :D
https://youtu.be/h3auMMXjmrQ?feature=shared
(please pardon the language....)
Obviously I now have to decide if I need to get that inlet stem tube replaced, (They're pressed into the head, so I need to find someone to do it for me), or if I live with it. The exhaust side looks a lot newer than the inlet one.
I'm going to hold off on lapping the valves in until I make that decision.
Still pondering the best way to clean the burnt on carbon from the inside of the head and barrel (and piston), without damaging any of the surfaces.
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... cont.
Got into the workshop this afternoon, and took the decision to just fuggin do it.
Timing chain cam off easily enough, the two sprockets were well jammed on, but I eventually got them off with the bearing puller.
There's no keyway or anything on these, so the ignition timing needs to be done by "eye"...
(https://live.staticflickr.com/65535/54428728699_f1dff1ed1e_z.jpg)
The platform the mag sits in is pretty mullered....
(https://live.staticflickr.com/65535/54428911545_30c78c189b_z.jpg)
Probably why it wasn't exactly firmly located.... :(
It was also only held on by 2 studs.
Here's the Mag drive shaft - note complete lack of keyways...
(https://live.staticflickr.com/65535/54428911560_fc1701c575_z.jpg)
But nice modern seal.
The foam on the Mag is to stop oil flying about from the timing case, because the hole the mag shaft pushes through is about an inch square....
This frigging engine mount bolt was the main reason I was swearing all afternoon....
(https://live.staticflickr.com/65535/54428781993_8d4961ca84_z.jpg)
The nut on the end was tight as hell and so I couldn't pull the stud out of the plates on the other side.
When I was talking to the guru the other day: he mentioned the "bible" for JAP speedway engines is the "Greenwood" manual.
So - I popped a search into ebay, and one came up! Score! It turned up today, and as I was reading it (it's only about 8 pages), I was thinking.... this is all very familiar.....
Checked the books/manuals in the workshop and ....
(https://live.staticflickr.com/65535/54428534841_d085737493_z.jpg)
ffs.
Dad had a photocopy of the damn thing. :roll:
The interior of the timing chest:
(https://live.staticflickr.com/65535/54428911455_cd3f87a550_z.jpg)
Note shonky paper gasket and crap.
See if you can spot the wtf...
Inlet cam roller
(https://live.staticflickr.com/65535/54428911385_285467b093_z.jpg)
Exhaust cam roller
(https://live.staticflickr.com/65535/54428534706_45a9686184_z.jpg)
WTAF?
(https://live.staticflickr.com/65535/54428911310_7434979e3e_z.jpg)
No - I could NOT figure out what that was.... took me an hour.
This is the inside of the timing chest cover - with the exhaust valve lifter gubbins:
(https://live.staticflickr.com/65535/54427681287_3171a697bd_z.jpg)
(https://live.staticflickr.com/65535/54428728344_a13585c58b_z.jpg)
(https://live.staticflickr.com/65535/54428781728_1cfe952dc3_z.jpg)
This is the cam-shaft in place in the timing chest cover
(https://live.staticflickr.com/65535/54428911030_7f351b0f54_z.jpg)
Close up of the cams:
(https://live.staticflickr.com/65535/54428728234_34a20a5b15_z.jpg)
(https://live.staticflickr.com/65535/54427681077_5805dbaa64_z.jpg)
I was looking at the valve-lifter assembly above, and comparing it the position of the valves... and I couldn't for the life of me figure out how on earth it was meant to do anything. The lifter assembly is the same "thickness" as the cam-shaft gear, and the exhaust roller is tucked away behind that gear when the chest is assembled ... so ... what did it "act" on??
I eventually worked it out when I got to pulling out the rollers :
(https://live.staticflickr.com/65535/54428781488_53096dce11_z.jpg)
(https://live.staticflickr.com/65535/54427681002_99f466941a_z.jpg)
That little stub of metal "was" a pin that had been driven through the exhaust roller arm, and which would then stick past the cam-shaft-gear and the valve lifter could act on that pin to lift the exhaust valve. But: the pin has obviously snapped at some point in the past: no wonder the valve lifter was utterly useless!! :D :D
TBH I'm probably going to just strip the lifter mechanism out completely, rather than try to get a new pin driven into the roller. It's only 9:1....
Inlet, and exhaust rollers:
(https://live.staticflickr.com/65535/54428728099_5dd947b891_z.jpg)
However... I think a new inlet roller may be in order, not sure, but I think they come as a pre-assembled part. :
(https://live.staticflickr.com/65535/54428728089_c73738f0b1_z.jpg)
(https://live.staticflickr.com/65535/54428781363_0ea069fa2e_z.jpg)
EVENTUALLY.. after quite a bit of twisting, looking, perusing, swearing and general $%^&&ery....
(https://live.staticflickr.com/65535/54428728049_caa90dddb0_z.jpg)
IT'S OUT!
(https://live.staticflickr.com/65535/54428534176_238f129fee_z.jpg)
And that was about all I really had time for. Next jobs are to continue stripping down the cases to check the crank bearings are still in good shape. Ideally I'd split the crank.... but I'm REALLY sure not sure I'm brave enough for that....
This frame really has been bodged about.
(https://live.staticflickr.com/65535/54428534101_54a76ef081_z.jpg)
(https://live.staticflickr.com/65535/54428534091_c8200df457_z.jpg)
This is the hole we were talking about... all the way back on page 1...
(https://live.staticflickr.com/65535/54427680832_ccedd9ebb1_z.jpg)
Hadn't noticed this nick on the conrod before.
(https://live.staticflickr.com/65535/54442889607_b4b4bc10e5_z.jpg)
I'm thinking this conrod is likely to be second hand, so the nick is likely old too. I hope...
(https://live.staticflickr.com/65535/54444120925_b7c6ed854c_z.jpg)
Some carbon on the piston.
(https://live.staticflickr.com/65535/54443932204_fe21f897c9_z.jpg)
(https://live.staticflickr.com/65535/54443746296_38a665a784_z.jpg)
(https://live.staticflickr.com/65535/54442889522_b7f2e92023_z.jpg)
From the pile of tools I brought back from Dad's workshop I eventually unearthed this, among the 5 or 6 other "pullers". Put a new bolt in it, for some totally unknown reason he had a carriage bolt in it.. :wtf:.
(https://live.staticflickr.com/65535/54443746241_b0acb529f2_z.jpg)
I had to file it down a touch, but it worked perfectly.
(https://live.staticflickr.com/65535/54443932024_dd2e95eedc_z.jpg)
One of the other pullers to remove the crank sprocket from the timing side.
(https://live.staticflickr.com/65535/54442889472_d56a9fe825_z.jpg)
This plate needs to come off, but I've no idea what it's been such on with, or what's behind it that I don't want to damage while removing the plate.
(https://live.staticflickr.com/65535/54444120755_6c190326cf_z.jpg)
Timing side of the crankshaft
(https://live.staticflickr.com/65535/54443986878_0246f78afa_z.jpg)
Piston is cleaning up nicely, but I'll keep at it.
(https://live.staticflickr.com/65535/54443931944_04346c7a48_z.jpg)
(https://live.staticflickr.com/65535/54444120645_dc1de82309_z.jpg)
(https://live.staticflickr.com/65535/54442889412_4c85f72451_z.jpg)
(https://live.staticflickr.com/65535/54443746126_72d1487abf_z.jpg)
Bit more progress on the JAPton strip down yesterday:
Stripped off the oil seal plate on the crank output shaft :
(https://live.staticflickr.com/65535/54485873075_062d75e8b3_z.jpg)
(https://live.staticflickr.com/65535/54485520021_1547d69a68_z.jpg)
I wonder if that's a modern update. I don't remember seeing anything about it on any of the diagrams or books, and the thing is held on with metric cap-screws... (well, I didn't check the threads, but they take a 3mm metric Allen key, and none of my Imperial Allen keys would fit....)
While I was fiddling with the output side.... I heard a "clonk" from the other side of the cases....
(https://live.staticflickr.com/65535/54485872490_ae161fcf46_z.jpg)
The oil drain box cover fell off. :D :D :D :D
I'd already removed the screws last time, but it had appeared to have been solidly glued down with silicon sealant... Apparently not so solidly! :D
(https://live.staticflickr.com/65535/54485872630_7e89d506ab_z.jpg)
(https://live.staticflickr.com/65535/54485794093_ec69edcc90_z.jpg)
Kellogg's still make the best gasket paper. ;)
The gunk inside the oil drain chest.
(https://live.staticflickr.com/65535/54484674977_79b0bb7c02_z.jpg)
(https://live.staticflickr.com/65535/54485519196_8e3f2b24cb_z.jpg)
This is the underside of the oil drain chest - it's a one-way valve of some sort - I'm going to clean up the mating edges for the outer covers, but otherwise leave this alone.
(https://live.staticflickr.com/65535/54485870975_58318c0479_z.jpg)
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... cont.
The scary part!!
(https://live.staticflickr.com/65535/54491208509_3c09ce2172_z.jpg)
Plonk! (tinkle tinkle tinkle..... feck where did the pins go!)
(https://live.staticflickr.com/65535/54490159172_c110b68a3f_z.jpg)
There's 10 of the little buggers each side.
(https://live.staticflickr.com/65535/54491291303_74daf1150c_z.jpg)
Output shaft:
(https://live.staticflickr.com/65535/54491208479_664edd77e0_z.jpg)
Magnet to pull the pins out when they refuse to fall out by themselves.
(https://live.staticflickr.com/65535/54491291288_7f359898fd_z.jpg)
Simple engines are great.
(https://live.staticflickr.com/65535/54491208429_39952dc244_z.jpg)
Timing side: ALL the pins fell straight out!
(https://live.staticflickr.com/65535/54491208419_4d28fb7fc1_z.jpg)
Timing side bearing liner is ok.
(https://live.staticflickr.com/65535/54490159127_67b2dbbfff_z.jpg)
Output side not so much....
(https://live.staticflickr.com/65535/54491018651_9af92e116e_z.jpg)
That patch feels rough as hell. New liner time.
I'm currently mentally debating the wisdom of breaking the crank down... looks simple enough... it's the reassembly that scares me!
(https://live.staticflickr.com/65535/54490159082_cc2cc5774a_z.jpg)
(https://live.staticflickr.com/65535/54490159077_0284ce1414_z.jpg)
Insides of the cases are epoxied to buggery. I don't know if this is my Dad's doing... but it's likely.
(https://live.staticflickr.com/65535/54490159092_96b5149b21_z.jpg)
(https://live.staticflickr.com/65535/54491361785_83d4d94ef3_z.jpg)
(https://live.staticflickr.com/65535/54491361790_2d3f55ca88_z.jpg)
(https://live.staticflickr.com/65535/54491208234_4f61f4e77e_z.jpg)
Another view of that liner.
(https://live.staticflickr.com/65535/54491361725_9ce1b4a803_z.jpg)
These "thimbles" screw into the cases and provide the base for the screw-down head rods
(https://live.staticflickr.com/65535/54491208204_b7cdfc1c82_z.jpg)
They're a git to get loose...
(https://live.staticflickr.com/65535/54491291043_4fe802ef98_z.jpg)
Paper gaskets infused with oil take heat well....
(https://live.staticflickr.com/65535/54491208179_9d8bf0edcd_z.jpg)
I'm reliably informed that the thimbles come out a lot easier if they're assembled with coppa-slip. Luckily, I've got plenty! :D
The thimbles have these little pucks underneath to stop any galvanic reactions with the cases (or that's what I've been told - it could be just to provide a flat step for the thimble to wedge down onto).
(https://live.staticflickr.com/65535/54490158892_8b31777f91_z.jpg)
Epoxy:
(https://live.staticflickr.com/65535/54491361645_9fda52cd97_z.jpg)
I'm glad to see that the drain plug hasn't been epoxied over....
(https://live.staticflickr.com/65535/54491018481_e6f6e07eb8_z.jpg)
Blue hylomar... my old friend!
(https://live.staticflickr.com/65535/54491291013_8e14a13dda_z.jpg)
You can sort of see the "lip" that JAP used to create a labyrinth seal on the cases here.
As said - I'm just pondering the wisdom of splitting the crank up to check the big-end bearings - they "feel" ok - but while I'm here it might be worth doing. I'm just being cautious about that because bolting it back up "straight" is going to be paramount.
All that only took me about 90 minutes, and I managed to finally get down to the local "Classic vehicles" club night and join the club - they do a monthly meet only about 3 miles from me so it's dumb really that I've not joined before now. Already hopefully got leads on a couple of hopefully useful contacts.
Just in case anyone is wondering: I'm using this thread mostly for myself to provide my thoughts and notes as I go, for reference to when I put it back together, or do it again! Pretty sure there's no-one else on the forum with a JAP speedway engine to dismantle.. :D (happy to be proven wrong though! :D )
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Ooops - looks like I've repeated some details there - sorry about that. :D
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"I'm just pondering the wisdom of splitting the crank up to check the big-end bearings..."
Yes it's a tricky one, perhaps depending on what you want to do with the bike. If you do pull it apart keep in mind that it is tricky to get it back together and running dead true. If you've not done it before best left to an expert? I've done it lots of times, and most often it's gone ok. Only once did it defeat me entirely (i.e. no better than a couple of thou run-out on the shafts after trying everything I know) and I had to pass it on to the expert who used appropriate (unknown to me) magic to get it running just so.
The epoxy is interesting. Often cases an an engine can be quite porous to oil and painting the inside with something (glyptal, expoxy of some kind) can keep the outside clean. Hopefully there's no major corrosion being covered up.
Leon
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"I'm just pondering the wisdom of splitting the crank up to check the big-end bearings..."
Yes it's a tricky one, perhaps depending on what you want to do with the bike. If you do pull it apart keep in mind that it is tricky to get it back together and running dead true. If you've not done it before best left to an expert? I've done it lots of times, and most often it's gone ok. Only once did it defeat me entirely (i.e. no better than a couple of thou run-out on the shafts after trying everything I know) and I had to pass it on to the expert who used appropriate (unknown to me) magic to get it running just so.
The epoxy is interesting. Often cases an an engine can be quite porous to oil and painting the inside with something (glyptal, expoxy of some kind) can keep the outside clean. Hopefully there's no major corrosion being covered up.
Leon
Yeah - I think I may have a contact with someone locally who runs a Cooper 500 car, so hopefully will have experience (or knows someone else) in doing that job. Even though the bike is only a road-bike, and is running low compression (9:1 and petrol as opposed to 15:1 on dope), I'd like it to be "as good as I can get it". Ideally I want to get into the cycle of "ride in summer / maintain in winter", however the learning experience of my first full strip down is taking longer than I had expected, mainly due to the unexpectedly poor condition of some components, and the lack of time I'm getting in the workshop. :D
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Small update.
I haven't really made much progress, but things have happened.
I found the ONLY piece of JAP hardware at Beaulieu Autojumble: a head, complete with fitted valves! Snapped it up for £130 and kindly refused the same seller's offer of £475 for an AMAL Type 27 twin float-chamber dope-sucker!
I think the Head was made up for use, and then either only used very briefly, or put to one side as a "ready spare".
It holds water :
(https://live.staticflickr.com/65535/54565385394_d1a424f27d_z.jpg)
But I want to be sure that's it's fully-functional condition so I've started stripping it down to check valve-stem rattles etc:
(https://live.staticflickr.com/65535/54565201521_6e3671abfe_z.jpg)
It's pretty clean.
(https://live.staticflickr.com/65535/54565435378_eb5a33a4d0_z.jpg)
But there's always room for improvement... (that's the exhaust outlet)
(https://live.staticflickr.com/65535/54565201476_04221774e9_z.jpg)
The valves springs sit in these cups:
(https://live.staticflickr.com/65535/54565435313_9e17d460c1_z.jpg)
And you have mica washers that sit underneath the cups to adjust the valve-spring compression. LIttle bit of verdigris here...
(https://live.staticflickr.com/65535/54565385279_36d5cc029e_z.jpg)
I've also arranged to take the crank up to the JAP speedway guru in a few weeks to strip it down, check the bearings and rebuild it (it's beyond my equipment and capabilities to rebuild the crank!) I'll hopefully be able to take some photos of the process, if I'm allowed. :D
I've also just put in an order for a few bits..... around £600s worth..... (new main bearings, new big-end bearings, new cam-roller, etc etc).
every step is a step forward.... (even if they're not very often!)
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In the interests of keeping up to date.... I also did some work last night.
Finished stripping down the "new" head. It's tidy.
(https://live.staticflickr.com/65535/54566829624_ccd379db2f_z.jpg)
The valve stems aren't the same - the inlet especially looks to have been either cut short, or made that way to reduce interference on the flow of the charge?
(https://live.staticflickr.com/65535/54566880888_85e7f53a63_z.jpg)
(https://live.staticflickr.com/65535/54566980555_e70e76c87c_z.jpg)
About an hour or so later after a dubious application of Solvol and a toothbrush...
(https://live.staticflickr.com/65535/54566880868_ea3f945be5_z.jpg)
(https://live.staticflickr.com/65535/54566880848_247ccf48a1_z.jpg)
(https://live.staticflickr.com/65535/54566650671_cc2c537dbf_z.jpg)
Bit nicer. :D
Polished up the back face of the valves too...
(https://live.staticflickr.com/65535/54565773702_8857a4a4a2_z.jpg)
(https://live.staticflickr.com/65535/54566880768_74299f99b9_z.jpg)
and then gave them a bit of a grind. I only used the "fine" grinding paste because they were sealing nicely before, and I just wanted to ensure the mating face was good after the polish. Obviously I'll test the seals again after reassembly.
(https://live.staticflickr.com/65535/54566650646_877fbc2c50_z.jpg)
Terrible photo of the excellent valve tool I inherited from my Dad. :D
(https://live.staticflickr.com/65535/54566880813_c64274197e_z.jpg)
(https://live.staticflickr.com/65535/54566980485_a55d28979d_z.jpg)
(https://live.staticflickr.com/65535/54566980460_6ee5ccac02_z.jpg)
That's a big hole....
(https://live.staticflickr.com/65535/54566829544_cc71e21bf0_z.jpg)
I also took some measurements of the inlet manifolds on each head. I'd read something about the evolution of the engine recently (must dig it out again), and that last photo made me curious....
Yup - they're different.
Head 1 (current) is 28.5mm / 1 1/8" internal diameter
Head 2 (new) is 32mm / 1 1/4" internal diameter.
I "believe" I'm right in thinking that if I want to use Head 2 (it's in better nick, has better valve stems and would appear to be "less old"), then I'm going to have to look for a new carb. IIRC the inlet manifold needs to be a consistent diameter/cross-sectional area for as much as is possible - which would mean that the carb would need to be consistent with that too. The current carb is an AMAL Monobloc (389/229) (http://"https://amalcarb.co.uk/carburettor-for-a-bsa-a65-lightning-hornet-1.html") which measures 1 1/8" across the "exit" hole (ie where the fuel/air mixture exits the carb). (Oddly, the AMAL website suggests (although they've taken off the details now) that that model Monoblox is a 1 5/32" which is ... err... 1 2.5/8" (I think...)). So... I'm a little confused about that .....
It does mean I have a reason to potentially get a better carb though.... According to this site (https://surreycycles.com/carburettors/amal-monobloc-376-389/) there is no 1 1/4" Monobloc so I don't believe I can get the same carb and therefore have use of my now extensive collection of jets...) Something different then.... probably something like a Mk1 Concentric or something. I do have to say it's very tempting to look at some throaty Dellorto or something equally esoteric though.... might suit the "crazy ... like a fox" nature of the bike. :D
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Wow, that's quite a nice piece of hardware. Particularly for £130, which probably wouldn't cover the cost of supply/fit new valves.
Re a potential new carb: If you're planning just to ride the bike on the road you might want to try the existing carb first. 1.25" is a seriously large carburettor; for example a 500cc works TT racer used a 1 7/32 carb - 1.2188" - in the 1930s, with a big megaphone, 6000+ rpm, bump start and very little idling. With a muffler and road riding, your existing carb might be fine.
Pleased the crank is going to an expert.
Leon
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That No2 head has had a lot of time sent on it. Polishing ports may look good but does very little extra in an engine for a road bike.
The carb will be fine (unless you are going to run it on methonal and throw it sideways around a dirt oval) and the small step from 1 1/8 to 1 1/4 wont be noticable on the road and the step will actually help with fuel reversion at low revs. Keep up the good work and enjoy the bike.
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That No2 head has had a lot of time sent on it. Polishing ports may look good but does very little extra in an engine for a road bike.
I know it won't make a huge difference - but the better I prepare it and assemble it now, the longer it should go before the next strip down. Hence new bearings etc going in.
The carb will be fine (unless you are going to run it on methonal and throw it sideways around a dirt oval) and the small step from 1 1/8 to 1 1/4 wont be noticable on the road and the step will actually help with fuel reversion at low revs. Keep up the good work and enjoy the bike.
In that case I just need to source a new manifold adaptor - (makes note to measure external diameter of head 2's mainfold)
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The exhaust seat has been well recut (several times) and pocketed ......not that it matters for road use ..........however it means that a new seating ring cant be fitted without major expense..........If your timing is extreme ,you need to be sure the valves wont collide ............Must say it seems strange to me that Burlen and others sell replica Amal carbs for astronomical sums ,when you can buy new carbs for 15 quid on ebay or temu.
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If anyone has been following this, I'm sorry for the hiatus: I lost my password and, for various reasons, couldn't retrieve it.... But I'm back now. :)
To continue....
(https://live.staticflickr.com/65535/54578426535_b670892e67_z.jpg)
The old head is slowly cleaning up. I resorted to violence last night (with the dental pick).
Old photo for comparison:
(https://live.staticflickr.com/65535/54423565562_25de3f03de_z.jpg)
(https://live.staticflickr.com/65535/54578278574_0e4aafa45f_z.jpg)
bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
(https://live.staticflickr.com/65535/54578323083_56feb83168_z.jpg)
They might not look it, but they're a lot cleaner!
Did the valves and springs in petrol, and the rest in paraffin (the only 2 solvents I had in).
Will get most of the rest of the components cleaned up as I start reassembly, once the crank is done. Off to Ipswich next weekend for that.
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Progress thus far:
First, the dinosaurs came, but they got all fat and sick and died and turned into oil, then came Mercedes Benzes....
ahem.
The visit up to the JAP guru in Ipswich went very well indeed. We got on very well and it was a fun morning of fettling.
I took up a few parts to get his opinion on their worthiness and discovered a few things.
Firstly - the 2nd head I bought is badly pocketed: the valves have been sunk into the head so far (by use and grinding in) that they're actually now "outside" the original hemisphere shape of the combustion chamber. I also found out the other day that the original head has had the valve-seats replaced (I think I knew this), so it's actually in better condition than Head 2 (despite Head 2 being cleaner... ).
In addition we dicovered that the exhaust valve for Head 1 is bent. That was a puzzler - because there's no evidence of it having hit anything within the chamber (the other valve, or the piston). It's why it wasn't sealing. Luckily he had a 2nd valve that slotted right in.
We also looked at the loose inlet guide, and he replaced it from his stock. I didn't know this... but the valve guides can just be hammered in and out! :wtf: The original valve fits in the new guide perfectly, so Head 1 will be back in action once it's fully cleaned up and re-lapped in. :D I'll probably by some flap wheels for my Dremel and have a go at the carbon build ups in the exhaust manifold myself, and then as a final resort take it to a media blaster of some sort. (walnut or vapour probably).
We also examined the rocker box : This is the best pic I could get of the issue :
(https://live.staticflickr.com/65535/54604466906_baa77296d7_z.jpg)
What I thought was wear caused by too much endplay in the rocker arms, is actually caused by the fact that the rocker arms are the wrong arms for the box! Well - not actually "wrong" - but they've not been fettled properly! The original forging patterns for the rocker arms make them too big for the rocker-box, and it's necessary to grind off a lot of the material. When he's doing race-engines apparantly he takes off quite a lot of the material on the rocker arms, including drilling lightening holes and a hole down the ball-end! (sounds painful!). So - I'm going to take off the material necessary from the rocker arms to ensure that there is clearance for the oil-gallery (shelf), and get that oil-shelf rebuilt up - that should ensure that the rocker-bearings get plenty of oil in the future. I'm hoping that I'll be able to do that to a reasonable quality using hand-tools... we'll see.
He also explained a good trick for checking the valve-spring weights, which I'll take photos of as I do it.
He checked the piston - it's fine (needs a clean), and the cam-shaft - which is a "standard", not a race item (which is fine), and also explained a few tricks for getting that aligned correctly should it need it. All stuff I'll be checking when I reassemble it.
Then we got onto the crank (and I remembered I had a camera.... )
Separating the big end shaft from the flywheel
(https://live.staticflickr.com/65535/54604769465_0fe09f1a39_z.jpg)
https://youtu.be/poGPWyDRhGg
:D
(https://live.staticflickr.com/65535/54604678668_e1aa0e5a7c_z.jpg)
Big end rollers - all looked ok
(https://live.staticflickr.com/65535/54603590042_19cb0732c0_z.jpg)
The big end cage is just ally - but it looked ok.
(https://live.staticflickr.com/65535/54604678628_80a56a7cc9_z.jpg)
Inner faces:
(https://live.staticflickr.com/65535/54604466786_036a99d237_z.jpg)
(https://live.staticflickr.com/65535/54604769355_e375a2b39e_z.jpg)
At this point there was a slight bit of confusion due to the distinct lack of balancing holes having been drilled in the inner faces, until I remembered it's a 350 crank (not a 500). :D Obviously new cage and rollers were fitted.
(https://live.staticflickr.com/65535/54604769335_274b824f7d_z.jpg)
Pressing the tapered big-end shaft back into the flywheel.
(https://live.staticflickr.com/65535/54603589972_be394d1370_z.jpg)
With some minor adjustments to get the outer diameter faces parallel :
(I now want a brass hammer!)
(https://live.staticflickr.com/65535/54604678483_72ed1714c9_z.jpg)
Things are much easier when you have the right kit....
(https://live.staticflickr.com/65535/54604678428_93a5ffab81_z.jpg)
More minor adjustments to the get the shafts aligned :
(https://live.staticflickr.com/65535/54604660164_766c256512_z.jpg)
This was very much an iterative process: take a measurement, squeeze the wheels, take a measurement, squeeze again... etc. etc
(https://live.staticflickr.com/65535/54604769090_6326fa0edd_z.jpg)
The for the first few checks the nut wasn't even done up as tight as it could be ... just f-ing tight. After getting it pretty damned close, he did the nut up even tighter (using a 4-foot breaker bar and a lot of bodyweight....) then spent another half-hour getting it just right: toed IN 3/4 of a thousandth of an inch on one side, and about 1 thou on the other side. Apparently under heavy load the crank can toe "out" and pinch the con-rod, so he sets them up toed in slightly.
At the end of the session he declared that it was a "good set of wheels". Which I'm very happy about! They should now be good for quite a while, and with the use I'm expecting from the bike (pottering about locally annoying the purists :D) they should outlast me.
As we were tidying up and nattering (another half hour at least... :D ) he realised that I didn't have a mag-platform steady bracket: it should look like this :
(https://live.staticflickr.com/65535/54604660089_8e94b406b4_z.jpg)
(https://live.staticflickr.com/65535/54604660079_4675fe3dfe_z.jpg)
(https://live.staticflickr.com/65535/54604769025_b6c4c13a07_z.jpg)
And this is how it's mounted : to the underside of the mag-platform, and to the crankcases.
(https://live.staticflickr.com/65535/54604466351_dcaf5349fd_z.jpg)
(https://live.staticflickr.com/65535/54604466291_72dac0f916_z.jpg)
(https://live.staticflickr.com/65535/54604659984_19b2ca5d3e_z.jpg)
The problem this fixes is engine vibration cracking the mag-platform supporting structure. So, while I have no idea why the engine didn't have one, it looks like a good idea to have one fitted so I'll try to either source one (I really should have asked him about that - so I probably will), or make one up. It needs to be good strong steel. (or whatever that fancy bronze-looking one is).
I now have all the parts ready, but still a lot of cleaning to do, and a few other optimisation jobs (eg lapping in the timing cogs to their shafts, and even lapping in the head to the barrel!).
-
I was reminded on Saturday of the existence of flap wheels....
So I ordered a couple up for the Dremel and attacked the carbon in Head 1's exhaust manifold
(https://live.staticflickr.com/65535/54611394986_88a16e8dd7_z.jpg)
(https://live.staticflickr.com/65535/54611610113_427799ca32_z.jpg)
Most of it was accessed pretty easily, and came off readily:
However - you can see the parts that the flap wheel wasn't getting to.
(https://live.staticflickr.com/65535/54611703530_fa167c65d2_z.jpg)
So I dug out some crap brass-brush accessories I bought a while ago for the Dremel - they're one-use only things (because the brass bristles come loose very easily), but they certainly worked:
(https://live.staticflickr.com/65535/54611610083_f280f67bf2_z.jpg)
I eventually gave in and started scratching away at the difficult to get to bits with a dental pick - you can see the scratches in the carbon here:
(https://live.staticflickr.com/65535/54610517267_876d8f3414_z.jpg)
Still got a fair bit to have a go at, but the worst is done. The main issue is trying to see what the f*ck I'm doing down there! :D
Oh yeah - I was also slowed down a bit by the Dremel extension constantly falling apart - either the central cable fell out of the driven spindle at the far end, or the outer rubber casing started melting and the fitting where the extension is screwed to the motor body fell off the end of the cable!
-
Bit of progress tonight.
I got fed up of picking away at the carbon deposits with a dental pick (it worked, but t's bloody slow), so I thought $%^&& it, and banged the valve guide out so I had unhindered access. And I could clean up the valve guide itself more easily. Having seen it done, and knowing that it's literally a hammer job, made me far more confident to do it. :D
Valve guide in improvised "gentle" vice (I really need to make up some ally / wood chuck covers for the big vice.
(https://live.staticflickr.com/65535/54616164590_5140eae4e4_z.jpg)
Much improved exhaust manifold!
(https://live.staticflickr.com/65535/54616054304_841ecb0396_z.jpg)
(https://live.staticflickr.com/65535/54616054279_edff9a5656_z.jpg)
I'm very aware that "polishing" the manifolds isn't going to gain me much, the engine is such low compression any gains are going to be minimal, but I wanted to do a "good job" on Dad's bike, and be proud of the end result (if I ever get there!), knowing that I did everything I could.
When I re-inserted the guide (it went in pretty easily, much as I had seen happen on Saturday), the outer end had been slightly peened closed (it happens) and I needed to ream out the guide. Luckily, I discovered that the 1 reamer I picked up from Dad's workshop was the right 11/32" size (funny that... :roll: ). Unfortunately it's a tapered shank, so I had to bodge it a bit and rotate it by hand using mole grips... :roll: But - it worked a treat and the valve is a nice snug fit in the guide. :)
I also polished up the valves (no photos, sorry), they're lovely now. :D
I then turned my attention to the valve springs. I wanted to check they were all still serviceable. The JAP guru I saw on Saturday had a lovely, expensive, american made tool for this - but he also described a manner of doing this using a drill press and a set of scales. So, I'd bought myself a set of postal scales that are up to the job: the desired spring weight is 145lb so a cheap set of kitchen scales ain't gonna cut it.
Unfortunately using it in the drill press didn't really work out, so I improvised...
(https://live.staticflickr.com/65535/54616164535_a4d9ce1b65_z.jpg)
(https://live.staticflickr.com/65535/54616164530_f480e809df_z.jpg)
:D
Might not be absolutely perfect to the micro-ounce.. but close enough for comparing the 4 different sets of valves that have against each other (at least).
I measured up all the springs I have - using a micrometer set to the correct length: 1.375"
The calculation is :
Desired spring length (compressed) : 1 5/16", Desired Spring weight at that length : 140-145 lb.
So - the cup and the plate within the cup that the springs sit in are 1/32" thickness each (where the springs bear) : added together that's 2/32" = 1/16"
So - add the cup & plate to the desired spring length and you get 1 6/16", or 1 3/8" = 1.375" (which is nice and easy to set on the micrometer, then lock off).
So - compress the springs, in the cups (with plates at each end), and measuring from the top of the outer spring (ignoring the top plate) to the flat sheet the cup is resting on. (In the head, you measure from the top surface of the head to the top of the outer spring, so this is the same measurement).
Results: Weight measured at spring length of 1 3/8" (inc cup & plate)
Head 1 inlet : 129 lb
Head 1 exhaust : 129 lb
Head 2 inlet : 151 lb
Head 2 exhaust: 145 lb.
So - the original springs are knackered. booo! :(
However - we have some nice springy springs from the "new" head. (albeit maybe a little over-enthusastic...)
I started mixing and matching to get roughly the right spring weight, but so far have only tried one combo:
Head 2 inlet outer + Head 1 inlet inner : 149 lb.
I'm going to play about with mixing the springs and get 2 pairs as close to 140/145 lb as I can. I think the measurement system is close "enough" for this. I was told on Saturday that if the spring weights are over 155 or so then they're too strong and they'll cause undue wear to the head. Given that head 2 is badly pocketed already I'm not wanting to take chances. Although Head 1 does had replacement valve-seats, so it's in a better condition.
Oh yeah - I also put the rocker arms and their accompanying accessories through the ultrasonic. Unfortunately I think I may have lost one of the frigging rollers though GAH! (mind you - I know I have a couple of spares because there were one too many in 2 of the assemblies!) Going to have to be a lot more careful with those little $%^&&ers.
-
Cleaned up the carbon in the barrel and gave it a hone. (Hoping I haven't over-done it tbh...)
(https://live.staticflickr.com/65535/54636935876_691b56c4f7_c.jpg)
I used a honing tool I bought at Beaulieu, and 3-in-1 oil (after doing a bit of research on cutting fluid/honing oil - from what I found it's basically just light oil).
I also had a god at the piston crown and it's now nice and shiney. (pics to follow)
-
Managed some time in the workshop yesterday.
Re-checked the valve springs.
(https://live.staticflickr.com/65535/54645264402_7d5283c71c_z.jpg)
Picked the two pairs that seemed to give the right spring weights and threw the into the ultrasonic.
Here's the shiny piston:
(https://live.staticflickr.com/65535/54646429230_d4953be982_z.jpg)
(https://live.staticflickr.com/65535/54646356183_26fd357eea_z.jpg)
Next step is to get the valves lapped, so I prepped the seats with a Sharpie
(https://live.staticflickr.com/65535/54645264322_8071406f25_z.jpg)
Loaded the valves..
(https://live.staticflickr.com/65535/54646356118_d79779d48a_z.jpg)
And did the Twist again!
(https://live.staticflickr.com/65535/54646356093_f90df85aba_z.jpg)
After a coarse grinding...
(https://live.staticflickr.com/65535/54646429070_53cf8b9f8b_z.jpg)
Then cleaned off the coarse paste, and prepped the valves..
(https://live.staticflickr.com/65535/54646356008_5b82ee1660_z.jpg)
After a fine grinding.
(https://live.staticflickr.com/65535/54645264152_1e7a948744_z.jpg)
(https://live.staticflickr.com/65535/54646428985_54440d8a38_z.jpg)
Next job ideally would be to lap in the head to the barrel, to ensure the mating surfaces where the copper head gasket sits mate really well, but there's a complication I need to discuss with my guy.
Where the head gasket sits is in a depression in the barrel, and the head has a matching "protrusion", and where the studs run is in the"outer ring". I'm not sure if the faces on the "outer rings" are supposed to meet or not.
Problem is that if the gasket is not in place, the "inner ring" faces don't meet when you sit the head on the barrel.
I'm not sure if I need to get some material machined off the top surface of the barrel or not.
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Closer inspection of the exhaust valve seat revealed a narrow part, so had another go.
(https://live.staticflickr.com/65535/54653811477_7201bdf317_z.jpg)
I think that should be usable now.
-
Decided to actually get into the workshop yesterday! (other things have been happening, or putting me off), and figured I'd have a tinker with the timing chest because I was advised to check the cam-wheel/cam-follower end play before I assembled the crank.
Firstly it took we a while to find the studs, then I realised that none of the threads were very clean, so gave them a good brass-brushing.
(https://live.staticflickr.com/65535/54871261023_340bb098b6_c.jpg)
But even then it seemed that none of the studs would cleanly go into the case, and some of the nuts refused to go down the studs easily. So I ran taps and dies over everything (took me at least 20 minutes to actually figure out the thread form and find the right taps & dies, which I DID have amazingly: turns out it they're 1/4x26tpi BSF).
(https://live.staticflickr.com/65535/54871275974_e274a0dc5b_c.jpg)
(https://live.staticflickr.com/65535/54871275694_dbe5f15ab4_c.jpg)
Eventually I managed to get everything spun down and tight.... then realised that one of the allen head cap bolts that are used inside the timing chain case was too long for it's hole! I can only imagine that Dad never noticed this bolt was the wrong length (nothing surprises me anymore...) so I cut them both down by about 5-6mm (well - the thickness of a nut) : I did both of them so I didn't have to faff with picking up the "correct" bolt for the shorter hole each bloody time.
(https://live.staticflickr.com/65535/54871025371_8bbbfb3723_c.jpg)
So - eventually I got the case to tighten down on the timing chest.... and the camshaft is jammed.
:wtf:
The Cam-followers are rattling around on their shaft as well - there's at least a mm of movement, if not more.
:wtf:
But it's the camshaft being jammed that is confusing the hell out of me. The bushes that it sits in are open ended so it's not like the saft is running up against the end of a closed hole.
The timing chest case DID have a paper gasket fitted when I stripped it down.... so I'm currently thinking that "maybe" the thickness of the paper gasket is what is providing the end-play gap offset for the cam-shaft itself.
Photos from the strip-down: you can see the paper gasket clearly.
(https://live.staticflickr.com/65535/54428911385_285467b093_c.jpg)
(https://live.staticflickr.com/65535/54428534866_426fcdcc9a_c.jpg)
So - the next job, I guess, is to make up a new gasket and see if that frees off the camshaft, and look for a proper shim for the cam-followers. I did find a ~1.5mm thick washer that was exactly the right internal diamater (1/2") to fit the cam-follower shaft, but the cam-followers did get "tight" when fitted - so again - if the paper gasket provides the offset.... this might work...
Oh yeah - also - over the summer I got some repairs done on the rocker-box parts:
(https://live.staticflickr.com/65535/54872303040_f0bce0b2a1_c.jpg)
(https://live.staticflickr.com/65535/54872254739_7e7eb93043_c.jpg)
(https://live.staticflickr.com/65535/54872239033_9d9e2c0f49_c.jpg)
(https://live.staticflickr.com/65535/54872302980_44977dd2a6_c.jpg)
The oil-galleries need to be machined back down to approx 3mm high and a similar thickness.
See here :
(https://live.staticflickr.com/65535/54871153397_9937d97e3e_c.jpg)
(https://live.staticflickr.com/65535/54404328467_14fc049c30_c.jpg)
TBH, I'm probably going to do this by just fitting a dremel-esque grinding tool into the piller drill and using it as an ersatz "single-axis machine-tool" and gently take the aluminium off flake by flake...
In addition the rocker arms themselves will be ground down to be narrower (and lighter), as previously mentioned.
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Another afternoon in the workshop, step forwards, step backwards.
(Actually, this was a few days ago)
Stripped down the Concentric I bought, it's not a Premier (which has a removable Pilot Jet, where the original Concentric has a fixed size bushing, and drainable float-bowl).
(https://live.staticflickr.com/65535/54888711340_b0cedc24fe_c.jpg)
It's "tired", which I expected, but all there and will make a reasonable back up if the Monoblock proves to be too much of a pain in the arse.
If I decide to try it, I'll probably invest in some updated components, gaskets, etc, and will give it a proper bzzzzzzzzzzzzzzzzzzzzzzzzzt.
The jets (at least) looks identical to the ones for the Monobloc, of which I have found quite a few in Dad's old bits so I can experiment with the main jetting at least (which is only really effective at full-bore.... ;) )
Yesterday I had a go at making the gasket for the Timing Chest
(https://live.staticflickr.com/65535/54888662964_c599193ccb_c.jpg)
Simple enough: the ball end of the hammer sheers the paper gasket on the hard edge of the facing with only gentle taps. These faces weren't really designed to have a gasket. Remember this is a race-engine designed for shale and grass-tracking with a total-loss oil system... weeping cases were a feature. :D Not great for the road or proper tracks though, so gasket making is something I feel I'm going to get lots of practise at.
Assembled up the cam-shaft and cam-followers again and its.... "better". the cam followers aren't sticking, but there's still resistance to movement from the cam-shaft itself. Stripped it down and smeared some R40 onto the cam-shaft and bushes and reassembled it
Liquid gold.....
(https://live.staticflickr.com/65535/54888647053_d5759b8dff_c.jpg)
That was an improvement, but still some stiction. So I stripped it again and smeared a lot more oil onto the camshaft, reassembled and just as I wsa tightening up the very last nut on it's stud.... $%^&&. I felt the thread go. Tried the camsaft rotation while it was all assembled and it's a tad better, but I still think it's a little tight, so will order up some 0.8mm paper (the gasket paper I had was 0.4mm) and see if that makes the difference.
In the meantime... stripped it all down again carefully... and $%^&&sticks.
(https://live.staticflickr.com/65535/54888421711_b66342d48c_c.jpg)
(https://live.staticflickr.com/65535/54888711090_3723c98576_c.jpg)
(https://live.staticflickr.com/65535/54888661048_4c7eaa7d15_c.jpg)
"Luckily" it's the hole at 5-o-clock on the face, which means it's got plenty of wall, and it's a blind hole (so no chance of crap falling out the other end later).
Hit the TracyTools website and found a 1/4" BSF thread repair kit which will hopefully turn up next week (grabbed some Imperial sized drill bits too, seeing as I don't have any at all, the sort of thing I'm sure to need at some point). Also ordered some more gasket paper.
Hey ho, not really that much of a surprise, but still a tad irritating.
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For someone with the same issues as Arthur Dent, I do seem to spend a lot of Thursdays in the workshop....
Decided yesterday to stop faffing and get on with some stuff.
First, I cleaned up the drive-side crank case where the main crank bearing liner was removed:
Before.
(https://live.staticflickr.com/65535/54890557233_e5c9da58e2_c.jpg)
After a few minutes with a brass brush and a wipe down
(https://live.staticflickr.com/65535/54889455577_7c3505f4d9_c.jpg)
I rigged up the hot-air blower in an articulated grabber (a digital tablet holder in fact), and took a preparatory reading
(https://live.staticflickr.com/65535/54890575104_7edd30a690_c.jpg)
After only a few minutes I turned it over to get a good spread of heat:
(https://live.staticflickr.com/65535/54890622845_14e85421f2_c.jpg)
Then I popped inside and retrieved the new liner from the freezer, where it had been hibernating for a few months....
That's the OLD bearing liner in the background of the photos.
When I got back, the temperature was even higher than this....
(https://live.staticflickr.com/65535/54890556753_42b7eb8c66_c.jpg)
The inside was a little cooler after I took the heat off:
(https://live.staticflickr.com/65535/54890574894_fa513391a9_c.jpg)
The new liner literally fell straight in, I was so surprised I didn't even remember to give it a tap, it didn't need it.
The little locating screw went straight in too.
(https://live.staticflickr.com/65535/54890574834_1cc679850f_c.jpg)
Light at the end of the tunnel!
(https://live.staticflickr.com/65535/54889455042_960828fe66_c.jpg)
This is the "feed" for oil to the main crank bearing....
While it cooled off, I pondered what to do next..... then decided to go for it and dug out the new bearing cages and pins.
oh, and the grease.... LOTS of grease!
(https://live.staticflickr.com/65535/54891011444_ae884e9c03_c.jpg)
To be honest, I think I used more grease just on these bearings in ten minutes than I've used in any single year of working on bikes....
For some reason the original size roller pins aren't made any more so the accepted practise is to use 2 pins for each slot in the cage, and alternate the positioning - as you can see in the photo.
(https://live.staticflickr.com/65535/54891061200_92ba4a846b_c.jpg)
Almost as soon as I'd taken that pic and was pondering on the pins: I realised: hang on: the old pins I took off are the OLD ones! I actually have the proper old full-length bearing pins... a complete set! But, given that I have no idea just HOW old they are, I decided to stick with the fresh ones.
So - the cases went together relatively easily for the dry-fitting, to see what the crank end-float is:
Crank pushed fully to the left:
(https://live.staticflickr.com/65535/54891011319_e02bea76d2_c.jpg)
Crank pushed fully to the right:
(https://live.staticflickr.com/65535/54889891852_82b10a15a5_c.jpg)
I measured the difference using a micrometer tail and it appears to be a movement of about 0.065" - I measured a few times, obvously, and I think the extremes were 0.078" down to 0.050" - so the consensus is about 0.065.
I checked what I'd written down earlier and read "crank end float : 0.12" - 0.15" ".
Hang on.... (I thought).
How can my end float be LESS than the desired?? Did the Liner not go in properly?? Have I got to take the liner out again?? $%^&&sticks!!
So - I ended up having a quick call with the Guru, and while I was talking to him I took another look at the book....
which read:
Crank End Float : 0.012" - 0.015".
GAAAAH!!!! what a muppet!!! I apologised profusely to the Guru for wasting his time, he was very nice about it and we had a nice chat about things anyway, and I got on with it whilst kicking myself!!
In my defense - I'm a metric kid, I've no concept of what thousands of an inch "look" like!
I agreed with the Guru that all the crank needs is some gentle shimming (phnar) and dug out the collection of shims I've got : some new, (iirc supplied by the Guru) and some from the original build.
0.050, 0.040, 0.023(*2), 0.020, 0.010.
So - with any luck - the 0.023 pairing should be exactly what I need! :D
Required thickness of shims: 0.065" - 0.015" = 0.05".
Desired shim width if using 2 shims : 0.05" / 2 = 0.025"
I can also potentially use the 0.010 and 0.020 to get it a bit tighter if required. but I'll have an afternoon of tinkering with that no doubt!.
I'm probably going to reassemble the cases again, dry, and double check that end-float, before deciding fully, but the crank looked pretty central so that should do the job.
This whole job was made MASSIVELY easier because I found a pair of legs for the engine last time I was in Dad's workshop:
(https://live.staticflickr.com/65535/54889891787_db5b65c122_c.jpg)
While I as pondering things I also noticed that the cases have another set of numbers on the rear faces :
(https://live.staticflickr.com/65535/54890763671_6094101a74_c.jpg)
I have no idea what these would be (they're not the engine numbers, those are on the front, on the rhs), and I'm tickled somewhat that they match, given that the cases are from totally different sources!
After I'd dissassembled the crank again to put it out of the way, I figured I'd make a start on the rocker box...
Measuring up the excess that needs to come off...
(https://live.staticflickr.com/65535/54891060915_e3fa82501f_c.jpg)
Answer: a lot. These little shelves are supposed to be about 3mm high.....
Setting up the ersatz "single-axis-milling-machine" (dremel grindstone in the pillar drill!)
(https://live.staticflickr.com/65535/54891011034_d66b80a930_c.jpg)
I used the grind stone first just to test the concept, and it worked well.
So I dug out a pot of cutting wheels. :D
(https://live.staticflickr.com/65535/54891010929_fb219b60c2_c.jpg)
I should state that there was a good long session of faffing with a bubble level to quadruple check that the everything was as flat as possible (the drill stand, the drill plate, the clamp, the workpiece, etc etc etc)
The main faff with it is replacing the cutting wheels every few minutes, but the rod that holds the wheel is chamfered about half-way down, so it's actually very easy to put it back into the drill in exactly the same place each time: with the chamfer butted up against the outer face of the drill-clamp jaws.
I got the first shelf (the exhaust side as it happens) cut down somewhat roughly and put the rocker arm together so I could check it against the shelf. There was still a of interference, so I decided to have a go at the rocker arm as well :
(https://live.staticflickr.com/65535/54889891532_b8d010ea41_c.jpg)
This was filing down the sides of the arm, to help it clear the oil-gallery/shelf. I also took it over to the grinder and shaved off quite a bit of the metal from around the bolthole where the ball-fitting is fitted.
I'll take more photos of the rocker arm next time I'm in there. Still a lot to do, but some good progress made I think.
-
oh - another thing - I'm now kicking myself for not picking up a rocker box I spotted at Ardingly last weekend. The seller wanted 200 for it, and was full of a story where he'd just sold one for 250. But simply having another one, with another set of rocker arms would remove a lot of the "peril" involved in what I'm doing right now.
I was looking back at some old photos of the stash of parts my Dad had before he died, there was at least 80% of another engine there: 2 rocker boxes, another head, another barrel, cases, a single crank wheel... but becuase I had no idea what parts were needed at that time, it was decided to send them off to auction. :(
So: I'm going to start stockpiling what I find from now on.
-
Got into the workshop on Friday evening....
Made some progress on the Rocker box: I figured grinding down the inlet rocker arm wouldn't take too long, and it didn't, (well, not that much!)
Inlet on left, unmodified. Exhaust on right, modified.
(https://live.staticflickr.com/65535/54892865091_60941e8bcf_c.jpg)
What need to come off mostly, is the material on the "underside" (as seen above) so that the rocker arm clears the little oil-galleries.
Closer pic beforehand
(https://live.staticflickr.com/65535/54893157685_07c28b754a_c.jpg)
Working the underside of the arm with files. I did the material around the "head", where the screw thread is, on the grinder, then tidied up with files.
(https://live.staticflickr.com/65535/54892865061_2a07825bbc_c.jpg)
Afterwards:
(https://live.staticflickr.com/65535/54893111239_d8f4e4b2b3_c.jpg)
I think I probably need to take a bit more off in that inner curve near the shaft, but that will depend a lot on how the clearance looks relative to the oil-gallery once that is cut-down.
This is all "rough-work" just to get the required clearances. The rocker arms will be flap-wheeled smooth and polished before re-assembly. I'm only modifiying the push-rod end. The other half that pushes down on the valve stem doesn't need any work: I'm only going for "usable" rather than "light as possible for racing".
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Update from Tuesday:
Got a lot more done on the rocker box.
Working on the inlet side oil-gallery
(https://live.staticflickr.com/65535/54902410884_40828e7208_c.jpg)
(https://live.staticflickr.com/65535/54902410899_846837dbb2_c.jpg)
Assembled the rocker arm bearing assemblies (which is a right faff) to check the clearances.
(https://live.staticflickr.com/65535/54902158661_0afc5bd0d9_c.jpg)
(https://live.staticflickr.com/65535/54902158671_b457a7887f_c.jpg)
(https://live.staticflickr.com/65535/54902410524_9bc2b44c2e_c.jpg)
(https://live.staticflickr.com/65535/54902410389_9d7a18be1f_c.jpg)
This is the rocker arms pushed as fair "in" as possible - which is the "worst-case scenario", I now have clearance here (just!)
(https://live.staticflickr.com/65535/54902158311_874d4542bf_c.jpg)
(https://live.staticflickr.com/65535/54902466410_519bf042f8_c.jpg)
I lost count of how many times I assembled, checked, stripped, filed/ground, cleaned off, assembled, checked, swore, stripped.......
But eventually ended up with a satisfactory clearance.
I was going for a "not-touching" clearance if the rocker arms ever closed up to the galleries, but when you assemble the box, the end-float is initially set by the pressue from the "lumps" on the inside of the cover. You set up the box with the bearing liner on the push-rod side as far "out" of the box as possible, and then do up the valve-side of the box tight, but leave the push-rod side screws slightly loose, so the rocker-arm bearing liner can be pushed in as the cover is screwed down, and that sets the "end-float" of the rocker arm. The photos below show roughly what clearance you get now.
(https://live.staticflickr.com/65535/54902410184_b93d73f71b_c.jpg)
(https://live.staticflickr.com/65535/54902466280_5c40bb47a4_c.jpg)
Should be good! :D
You can also just make out that I chamfered off the outer edges of the oil-galleries to give a bit more clearance. (you can see the chamfer grow through the photos :D )
And finally, gave the little buggers a polishing:
(https://live.staticflickr.com/65535/54902293496_77b6d7a759_c.jpg)
(https://live.staticflickr.com/65535/54901422417_6dc5b6a3de_c.jpg)
(https://live.staticflickr.com/65535/54902529248_c06d140680_c.jpg)
(https://live.staticflickr.com/65535/54901422242_88ac985988_c.jpg)
The other ends (the valve ends) now look a little 2nd hand.. :D So I "might" give them a gently polish if I can be arsed.
I may also borrow the kitchen scales to see how different they weigh, but I'm not sure it'll be much of an issue.
-
Managed to fix the stripped thread in the timing chest last night.
I've done this fix a few times now and it's normally relatively simple:
Drill out the hole - I took it slowly, the cases are (iirc) magnesium alloy, so they're not hard to work (and not ferrous...)
(https://live.staticflickr.com/65535/54906422400_8a6f387db6_c.jpg)
Tap the hole
(https://live.staticflickr.com/65535/54906113726_023b09716f_c.jpg)
Wind the insert in: Instructions say to use a light downward pressure.
(https://live.staticflickr.com/65535/54905240827_2a082f817d_c.jpg)
Then ding the end of the insert off, invert the workpiece and the debris all falls out: simples!
Tested a stud in it... won't go in. eh?
Look closely:
(https://live.staticflickr.com/65535/54906422160_6c0f87b758_c.jpg)
f******* c*********!
The damned insert jumped the threads.
This is one of the other holes - you can see the threads clearly
(https://live.staticflickr.com/65535/54906113466_76446a30e2_c.jpg)
Here's the "fixed" thread : you can clearly see the "threads" are twice the pitch
(https://live.staticflickr.com/65535/54906363744_13ab0a82fb_c.jpg)
So - sat back, started searching t'internet for "how to remove a thread repair", and found a lot of bollox about other types of thread inserts and repairs - but then finally came across this photo :
(https://rivetfix.com/wp-content/uploads/2025/07/How-To-Remove-Threaded-Inserts-1.webp)
And I thought: Hey, I've GOT a tool like that somewhere!
Yup - dug it out and presto!
(https://live.staticflickr.com/65535/54906341848_5d0d9133a7_c.jpg)
(https://live.staticflickr.com/65535/54906363679_25c1a18ce9_c.jpg)
Came out easy. :D
The tapped threads were still useable.
(https://live.staticflickr.com/65535/54906113266_97338c6bdd_c.jpg)
Wound in a new insert (there were 20 in the box!) this time with no downward pressure at all, just gently rotated the tool, and it wound in easily and properly. :)
(https://live.staticflickr.com/65535/54906341708_a6e5dc8d32_c.jpg)
After tidying up all the swarf, which took a while, (I must sort out that air-compressor), I started gathering the bits for making a start on the new gasket, but realised I was running out of time for the evening so packed away again.
I also discovered that the oil-box cover (the volume under the timing chest), screws are also 1/4 BSF, so if any of them go, I know I've got repair inserts. :)
-
Made up the new Timing chest gasket last night.
Started out with locating the bolt holes
(https://live.staticflickr.com/65535/54917732244_09122fe6f1_c.jpg)
(https://live.staticflickr.com/65535/54917698078_fb234648bb_c.jpg)
Punched them using a 6mm punch (closest thing to 1/4")
(https://live.staticflickr.com/65535/54917480741_ef5f1ef846_c.jpg)
I hammered the edges round for about 20 minutes, and got the inner shape punched out, then tidied up the outside with scissors.
This is why kids get taught to make crafts....
(https://live.staticflickr.com/65535/54917480716_8fa40ec515_c.jpg)
Perfect fit.
(https://live.staticflickr.com/65535/54917731994_878e95654d_c.jpg)
The active components installed
(https://live.staticflickr.com/65535/54916620087_e26dd0df7f_c.jpg)
All perfect! The camshaft rotates freely and there's a little bit of play on the cam-followers, but not enough to worry about.
(https://live.staticflickr.com/65535/54916619997_c0d0f68fdd_c.jpg)
I'm still pondering on getting some cap-head bolts to use instead of the studs and nuts. Dad did have that on one of the earlier incarnations of the bike, but I've no idea why it's back to studs and nuts.
(https://live.staticflickr.com/65535/54917783620_a26371e28d_c.jpg)
So - here's another mystery. I dissassembled the timing chest again because there's still a lot to do before final assembly, and while I was doing that, a washer dropped out of nowhere into the chest.
w.t.a.f. ??
Where did that come from?
Cue about 20 minutes of utter bafflement and poking and prodding. The workbench was utterly clear before I started, and this washer definitely "fell" into the timing chest - I saw it and heard it happen!
It's NOT one of the washers from the outer casing - there's 4 of them and besides the fact that I count them all on, and count them all off again each time I assemble and dissassembly the thing: it's not the same diameter. It's 1/4" alright, but it has a slightly smaller outer diameter.
EVENTUALLY I worked out that it had come from the socket cast into the outer casing which the cam-follower-shaft pushes into.
In fact... there's 2 of them in there.
(https://live.staticflickr.com/65535/54917731864_7d1071fe96_c.jpg)
I can only surmise that they were "stuck" in the by a little bit of oil that was still in there, but still baffled as to "WHY" they are there. The cam-follower-shaft is pressed into the main cases, it's going nowhere fast (or at all!). I reassembled the chest with the washers removed to see if they were having any effect on the gapping: none whatsoever, then reassembled it again with them in place: no difference that I could see to anything at all.
I am confuzzled.
Given that they were there to begin with: I'll likely replace them on final assembly... maybe they stop vibration or something??
So. I stopped thinking about that, it was giving me a headache....
And I looked at my stock of old bits of metal, and decided to make up a mag-platform bracket.
I found a length of steel that looked about right - I think it was originally part of a foot pump...
Faced it up to the cases a few times and realised it just need a straighten and a twist.
(https://live.staticflickr.com/65535/54917697808_6aa9afe374_c.jpg)
5 minutes of heat (gas-can-torch) and some judicious heaving and belting with a hammer....
(https://live.staticflickr.com/65535/54917783335_967c0ea655_c.jpg)
Checking the fit with a stand-in bit of engine plate
(https://live.staticflickr.com/65535/54917783350_5d9a5d1201_c.jpg)
Of course I've made it so that it's bolting to the WRONG engine bolt.... the one I was shown by the Guru actually bolts to the smaller lug you can see on the photos. D'oh! BUT - it should do the job, and may even be a little easier to fit and means I won't need to compromise the engine plates (any further).
Obviously it'll be tidied up and (probably) polished once it's been proven.
Next, I turned to finding a plug for the valve-lifter-cable-hole. I'm not going to bother with the valve-lifter, at least to start with.
It may become necessary later, so I'm not throwing it away, I'd need to get the exhaust cam-follower modified again by someone with a proper machine shop.
However - all last year I managed to turn the bike over without the valve-lifter working (I always thought was as innefective as hell) so, despite a dodgy right knee, I'm hoping I'll be ok.
Rummaging through all the stuff I've got, I eventually found something that matched the threads in the casing:
(https://live.staticflickr.com/65535/54917697578_a6e17646f8_c.jpg)
No idea what this stud was from originally, but it was in the "odds and sods" box and the only person who might know isn't with us ( :( ).
it's 7/16" x 26tpi.... which makes it a British Standard Cycle thread. (anybody got Bingo yet?)
It's tempting to look for a bolt in that spec... but tbh, I'm going to just cut the stud down, saw a slot in one end to make it a flat-head-screwed grub screw and be done with it by using a lot of loctite. :D TBH, the threads at the bottom of the hole are knackered, so the stud only goes in about 3/4 of the depth, so it does "go tight" by itself. The loctite will be to guarantee permanance. (obviously I'll be using blue.)
I'm also going to redo the plug in the top of the main cases that is over the cam-follower shaft: the plug that's in there is loose and is only being held in place by silicon sealant.....
-
The Cycle taps and dies turned up yesterday..... :D (I ordered a set of 5 of each, 26 TPI : 1/4", 5/16", 3/8" 7/16", 1/2" as a loose set, far far cheaper than ending up having to buy them separately).
I first cut the end off the stud that I had found, tidied it up a bit and span the 7/16 Die down it to clean the threads. Then cut a nice deep slot in the top.
It fits perfectly.
(https://live.staticflickr.com/65535/54929542087_6d3769ef69_c.jpg)
Because the thread in the case doesn't go full depth, the plug does go tight.
(https://live.staticflickr.com/65535/54930413101_7409e66d36_c.jpg)
Internal view.
(https://live.staticflickr.com/65535/54930720365_157a925639_c.jpg)
Hmmmm decisions decisions.....
(https://live.staticflickr.com/65535/54930719965_3480129155_c.jpg)
In the end I went with the 248, and slathered it all over. Should keep it place!
Buoyed by that success, I turned to the magnesium engine case:
First I made up a sacrificial wooden block to stop the drill plunging into the cam-follower shaft:
(https://live.staticflickr.com/65535/54929541377_dfc7af56d9_c.jpg)
hmm - that ain't gonna fly: :(
(https://live.staticflickr.com/65535/54930658314_a3326c96f1_c.jpg)
So it got mounted in the vice.
(https://live.staticflickr.com/65535/54930617588_44e7d95b08_c.jpg)
Drilled the hole using a very specific imperial size (which I've now forgotten, albeit it is written down in the notes in the workshop) after about 20 minutes trying to find out what the correct tapping drill size should be for a 7/16" cycle thread.
My Zeus book is a Metric edition, so while it does have "some" Imperial information (ok, a lot), it's not comprehensive. And the tables in this book https://www.sunbeamland.com/wordpress/wp-content/uploads/2019/04/The-Vintage-Motorcyclists-Workshop.pdf which I am using quite a lot, have a gaping hole in the Cycle tapping drill sizes table. (see page 8) :(
I initially found information that suggested 13/32" but then found something else that suggested the next size down (XX/64 iirc) was suitable, and even that was a conversion from a metric measurement : ie the given measurement was a metric one, and I had to figure out the closest imperial drill.
So - drilled the hole, slowly and gently and when I hit the wood, it protected the shaft beneath adequately.
I re-oriented the cases for tapping the hole and remembered why I hate doing jobs like this:
(https://live.staticflickr.com/65535/54930617243_c08d38fb9c_c.jpg)
It looks a lot worse than it actually is....
TBH I think the hole was a little narrow and maybe I could have used the larger drill size and the tapping would have been easier - but then I am not sure if the thread would be actually deep enough (ie the peaks of the threadform could have been flattened if I'd used a larger drill bit).
Next time I buy taps I'm going to try to buy the drill-bit from the same supplier and order over the phone to make sure I get exactly the right bits.
So - anyway, this hole isn't used for anything, it just needs plugging so a slightly off-axis thread isn't going to stop that.
I moved to plug.
Because I had a stud to cut for this, I screwed the stud in all the way until it ran out of thread and started to go tight in the hole. Then marked the untheaded part that was sticking out, and the excess that was protruding into the timing chest, and cut the plug out. Ran the Die down the threads to tidy them and cut the slot in the top:
(https://live.staticflickr.com/65535/54929540422_f261e0f68b_c.jpg)
I seemed to have cut the plug a little shorter than I intended:
(https://live.staticflickr.com/65535/54930719100_64f6aca980_c.jpg)
(https://live.staticflickr.com/65535/54930657539_10168681e4_c.jpg)
But it descends to the right depth: Because it was cut from a stud, the plug threads don't go full length of the plug - so it can be done up "tight". (Given that the head of the plug is below the level of the casing outer this would indicate that the threads in the hole aren't 100% at the top of the hole - probably due to my cack-handed tapping :( But - it's a plug, it's tight, it's good enough and a learning experience for the next time).
(https://live.staticflickr.com/65535/54930616288_cb80d6849e_c.jpg)
Fitted and loctitied, after cleaning the cases out with (iirc) carb-cleaner and a lot of blue paper.
(https://live.staticflickr.com/65535/54930657264_3f665dbf40_c.jpg)
By that time I was reasonably happy with the evening's work and headed in for chicken kiev and chips. :)
Next job is (I think) either to re-assemble the head: I'm pondering whether to have another go at grinding the valves in but I had a look at them last night and I think they're ok; or to get the crank shimmed up and then assemble the crankcases together.
I may have to look for a taller pillar drill so that I can get large objects under it properly: if I'd had the tap in the pillar drill to begin with, that hole in the engine cases would have been tapped much straighter. My drill was a random find at an impromptu garage clearance and is a hobby-ist wood drill really.
-
I'd been dong some general tinkering the last couple of evenings, it's frigging cold out there so anything that requires proper thought is being put to one side.
I was going to reassemble the head, and made a start: I'm only going to put a couple of mica washers on each spring assembly because the spring weights are good:
(https://live.staticflickr.com/65535/54936859505_e25afba806_c.jpg)
But then I discovered that the valve-stem circlip I put on looked very tired, so I thought, bugger it - should replace them, and tidied the head away again for later.
I've been looking at the engine cases trying to figure out the best way to get the upper-surface as flat as possible (ie where the cylinder sits), and realised that the two small engine case bolts that are the first two that get used, and which hold the cases together while the engine is mounted etc really should be proper shoulder bolts, and I've got 2 set-screws. So I'be been trawling the net for a 1/4" BSC bolt with a long shank (7/8"). See my other thread for details : https://revtothelimit.co.uk/viewtopic.php?t=11380 .
So - while I was in the workshop last night I had a good furtle through my collection of Imperial bolts from random sources..... and lookee here!
(https://live.staticflickr.com/65535/54936859435_cc40d81d22_c.jpg)
"Bolt" ( aka "Partially-threaded-Bolt") on left, "Set-Screw" on right.
No idea where this came from... but I have a feeling it may actually be the exact bolt that Speedway Service sell!
(https://images.squarespace-cdn.com/content/v1/5128f249e4b006d82fb859dd/1516306735436-1ZAP5FLWHU87KQJTJCFB/34%2BChances%2Bclamping%2Bbolt%2Bfront%2Band%2Brear.jpg?format=750w)
Knowing my Dad, he probably didn't fit this because it's actually too long, and would look odd. It's longer, to allow the Magneto Platform Support Bracket to sit on it!
Win!
So - I spent the rest of the evening cleaning up the engine studs:
(https://live.staticflickr.com/65535/54936756688_b3e5903b86_c.jpg)
And then, because the Mag-Platform bracket was on my mind and something was feeling off.... I bolted up the cases (empty) and fitted them into the bike to check a few things :
This is how I was initially envisaging the Mag-Bracket sitting :
(https://live.staticflickr.com/65535/54936756828_1d88df22e7_c.jpg)
(https://live.staticflickr.com/65535/54936555516_6369e21736_c.jpg)
But... there's an issue:
The engine stud isn't long enough.
(https://live.staticflickr.com/65535/54936803409_89d3bec404_c.jpg)
I'm going to have to rethink that Mag-platform bracket. Even though it will be a pain making sure it clears the engine plates - I think I'm going to have to use the smaller bolt as per the usual practise, so I need to remake the bracket. With any luck I can use the existing piece of metal, but if not, I do have more of that stuff, which is quite handy.
This is the rider's view when in the usual riding position :
(https://live.staticflickr.com/65535/54936555331_eeddd24816_c.jpg)
The cylinder axis is directly in-line with your head! :D
Incidentally: You can see the longer 1/4" engine bolt in that photo.
While I was looking at less-fundamental things I also tinkered with the "saddle-bag" fitting that I have never been really happy with: it's a cruiser-style "yoke-bag" that uses two thick leather straps and I had it hanging by the side of the saddle, banging against the shock:
(https://live.staticflickr.com/65535/53125829705_e846708bb1_c.jpg)
I was never really happy with that arrangements, so spent some time trying to figure out a way to improve it, and found a length of Dural in the box of metal bits that Dad had drilled a large number of holes in: no idea what it was for - maybe an early attempt at a brake-tension-arm or something, but it's absolutely ideal for mounting this bag onto the bike. I'll do more photos when I do more on it, but I spent some happy moments on the grinder tidying it up somewhat for use.
So - as part of that I looked into where it would be mounted, and discovered something that made me both laugh and curse.
The bike has always been "bangy" at the rear end when riding. It crashes about and is noisy, not just from the engine. I now know why....
(https://live.staticflickr.com/65535/54936803249_9a8866848f_c.jpg)
(https://live.staticflickr.com/65535/54936859025_9140e9a7db_c.jpg)
(https://live.staticflickr.com/65535/54935678242_a302c243f8_c.jpg)
(https://live.staticflickr.com/65535/54936756558_fc0f9f6a7e_c.jpg)
The shock uppers have at least 1/2" of movement side-to-side!! :wtf:
I need to look into what a regular Featherbed frame setup uses here - but at the very least I need a couple of 1/4" spacers to hold the shocks in place properly! I also think that the bolts should again have longer shanks, so we'll see what can be found, or bought to bring these shock support mounts up to scratch.
$%^&&in ell....
-
Hmmm - looking at this....
(https://andover-norton.co.uk/img/imagescaler/ce/cedfde55a6347ab4b31cf8e1f8122032.jpg)
Those suspension mounting brackets are not standard...
The wideline frame doesn't have cupped shock mounts either :
(https://andover-norton.co.uk/img/imagescaler/16/16bf2f21b68e81d4af2c687f14774260.jpg)
Anyone got a lathe?
-
Did some more tinkering on Friday night:
This is the dural bar I mentionted previously:
(https://live.staticflickr.com/65535/54938712914_efba8359e9_c.jpg)
The intention is to use these two holes - yes, yes one of the bolts is the upper shock mount, but it'll be fine.... ;)
(https://live.staticflickr.com/65535/54937583187_643e8d3c9e_c.jpg)
Just a shot of the general arrangement of what's under the saddle unit:
(https://live.staticflickr.com/65535/54938712794_14ac22df76_c.jpg)
Current shock mounting bolt on bottom... hmmmm
Two found 3/8" bolts above - much better shanks!
(https://live.staticflickr.com/65535/54938460896_dee8c136f0_c.jpg)
"Found" bolts is pretty much the right length (2"), but not completely convinced that the shank is long enough.
(https://live.staticflickr.com/65535/54938460891_0a69e9bd1f_c.jpg)
Ideally the shank of the bolt should interface with the inner part of the shock mounting plates as well as the full width of the shock eyelet. This is to reduce shear forces on the bolt - thread forms are a weak point when dealing with shear forces.
The Allen-head bolts looks trick.... so if I end up searching for custom bolts I "may" go back to Allen heads - but the hex-head is a loer profile which bh, I think I prefer.
(https://live.staticflickr.com/65535/54937583002_55e4c18b6b_c.jpg)
I was cleaning up the botls and looking for possible bits and pieces to convert into spacers, but I had a bit of a blocker happen when I used one of the new Cycle thread Dies to clean up the thread on one of the bolts. They were a bit manky (but good), so I cleaned them in the usual style with a bras brush, but then decided to spin the Die down them as well. Loaded the die in the stock for the first one, and started running it down the thread.
Hm - this is a bit stiffer than I expected... but maybe the gunk in the bottom of the threads is harder than I though.... carry on...
Got most of the way down the thread and took a much closer look - and realised in shock that the thread had been destroyed! The top half of the thread form had been scraped off uniformly all the way down! I ran a cycle nut down the thread and it IS a cycle thread, checked the other found bolt against the TPI guage, yup - 26TPI, and the mutated thread on the bolt also checked out as 26tpi. Checked other known 26tpi bolts and nuts....
the friggin Die is damaged, or badly made. :angry-cussingblack: :angry-cussingblack: :angry-cussingblack: :angry-cussingblack:
Checked the other dies from the same purchase, and where I had a known good bolt - the dies ran fine (1/4" and 5/16" seems to be all I have in known good bits and bobs).
So - going to have to ring the supplier today and see what can be done. Thankfully I've only wrecked one bolt... but it's a tad frustrating. :roll:
I've also been thinking about these bolts and where to get bolts with a proper long shank, and I think I'm probably just going to have to get the longest 3/8" bolts I can find, with the longest shanks and turn down the thread to match what I need. Buying custom made bolts will most likely be ruinously expensive, I don't really need 1000+ of the bloody things. :D
-
I've had another project on the workbench for the past week, but managed to find myself at a loose end on Saturday morning.... always dangerous...
I found myself looking at the wiring "loom" on the JAPton and thinking how messy it looked....
Especially things like this connector block near the battery :
(https://live.staticflickr.com/65535/52683281294_9094c0ca35_c.jpg)
The connector block cable-tied to the cross-beam visible in this photo: (left of photo, lower part of cross-beam)
(https://live.staticflickr.com/65535/52682997936_c48d577061_c.jpg)
And especially this mess:
(https://live.staticflickr.com/65535/52683429075_e0be2fbd09_c.jpg)
In regards to this - I really dislike the way the horn (black button) wire just dangles down to the headstock.
So - I perused, and pondered, and tinkered and eventually...
(https://live.staticflickr.com/65535/54953288618_55d339feeb_c.jpg)
Yes the horn IS wired in.
(https://live.staticflickr.com/65535/54953288658_785279271c_c.jpg)
(https://live.staticflickr.com/65535/54953104681_2e1a133166_c.jpg)
(https://live.staticflickr.com/65535/54953401835_ef23e93571_c.jpg)
(https://live.staticflickr.com/65535/54953288463_393f860bbc_c.jpg)
No new holes were drilled - all these holes were pre-existing (for one reason or other...)
A make-do 'grommet' at each end
(https://live.staticflickr.com/65535/54952217097_441eab1f2d_c.jpg)
(https://live.staticflickr.com/65535/54953288488_9482b7f184_c.jpg)
At the other end - the feed wire to the brake light has always bothered me because it was pulled quite taut, so I soldered on an extension to the yellow wire (which is the wire between the brake light switch and the bulb), and gathered up the few wires that actually needed to be all together with a Wago instead of a shitty plastic screw block. The Wago is glued to the battery.
(https://live.staticflickr.com/65535/54953288283_da82213a89_c.jpg)
(https://live.staticflickr.com/65535/54953288188_3f0a81346f_c.jpg)
Much neater.
(https://live.staticflickr.com/65535/54952216922_d48b42ec6d_c.jpg)
The entire wiring circuit is simple 2 loops - one for the brake light:
Battery -- switch --- bulb --- battery.
And one for the horn:
Battery --- horn --- switch --- battery.
It's currently setup as a "positive earth" with the frame as earth - so both the horn and brake-light simply earth to their nearest bit of metal, and the battery has a wire from the + terminal to the frame. Nice and simple.
The 3rd "out" connection at the Wago is for a battery charger connection that I wired in so I could charge the battery directly without removing the seat.
I may try to do a bit more tidying up - the horn wires are just loose and could probably do with "looming" together at some point, and similarly the group at the Wago could be tidied, but generally I'm happy with the end result.
There is also the Kill-switch to be replaced - but that will be moving to the right handlebar and is part of the Mag/coil/plug wiring circuitry which are totally separate from the "ancilleries" wiring. Yes - there's no way to charge the battery, so it has to be charged up before a ride... but it's "only" powering the horn and brake light (the brake light will be replaced with an LED at some point) so it's just a case of making sure it's charged before use.
Nasty looking little home-made implement for hooking wires through holes.... may well come in handy. (made from a dentist pick that had lost it's end.)
(https://live.staticflickr.com/65535/54953288193_949c4aa98d_c.jpg)
(https://live.staticflickr.com/65535/54952216792_26487cde93_c.jpg)
-
Remembered I had some loom tape yesterday, so completed the job:
(https://live.staticflickr.com/65535/54957024107_d4c397dba1_c.jpg)
(https://live.staticflickr.com/65535/54957916611_7b6da7a847_c.jpg)
I also took some remediating action concerning the battery flopping about on it's single screw....
(https://live.staticflickr.com/65535/54958161979_77caa4b594_c.jpg)
Will help for now - but a better solution will be engineered eventually.
-
Managed a couple of hours yesterday in the workshop:
Polished up what I could get to on the conrod :
(https://live.staticflickr.com/65535/54964058733_6ba494bbee_c.jpg)
And the sides of the fly-wheels:
(https://live.staticflickr.com/65535/54963878021_e271efb505_c.jpg)
Probably won't make a gnat's chuff of a difference but it felt like the right thing to do. Someone's had a go at the flywheels with an angle-grinder by the looks of it, so a mirror finish ain't gonna happen, but they're a lot shinier now
Then turned my attention back to the mag-platform bracket. I want to get this sorted before I assemble the crank in the cases because dealing with the cases and how they fit in the bike is a lot, lot easier when they're empty!
I spent about an hour repeatedly heating and belting the hell out of the bracket I'd previously made to try to get it to reach the smaller case-bolt where it's "supposed" to mount to.
(https://live.staticflickr.com/65535/54964133714_3b33a72799_c.jpg)
This is as close as I could get it:
(https://live.staticflickr.com/65535/54964183615_90e5233889_c.jpg)
To be honest, I think that bit of steel has had enough of me hammering at it.
So, I dug out another couple of potential victims:
(https://live.staticflickr.com/65535/54964183605_02483397e0_c.jpg)
Will assess these for suitability and have another go next time.
-
Mag-Platform bracket mk2:
In progress:
(https://live.staticflickr.com/65535/54973372140_bcf0171ab2_c.jpg)
In place:
(https://live.staticflickr.com/65535/54973074551_b654a514cd_c.jpg)
To be honest.... I'm not convinced. I bent that bit of steel cold, with just a hammer and then twisted it with mole grips. I think it's just a bit of mild and may not provide the support that I would get with the thicker stuff. :(
But - it'll do initially and I can have another go if I decide I want to. At least now I have a "pattern" piece for reference when making another one.
I made this one by doing the bend first: after figuring out roughly where it should be with the bracket bolted to the cases; then I put the twist in to bring the upper hole (the mag-platform end) into alignment with the underside of the mag platform. However - that meant that the twisted part of the bracket works against getting the bracket flat against the mag-platform.
If I try again, I'll probably start at the other end - the mag-platform end, and work out what the bend needs to be from that end. I thinkt it could be done with a single bend, but at a funny angle across the bracket, it's not quite 45 degrees - maybe about 30 or so.
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A few more steps in the journey on Friday night last:
I ordered up some bolts for the rear-shock mounts, but there was a communications failure and they turned up with the wrong specs:
The shank length should be 1"5/8s, (1.675"): hey ho... more on the way... I'm sure these will be useful somewhere else.
(https://live.staticflickr.com/65535/54979194477_781ecf8eec_c.jpg)
I want the shank that length specifically so that the threads are not bearing on the inner mount plate, but the shank is.
New spacers for the rear-shock mounts: these are perfect (and a right git to fit).
(https://live.staticflickr.com/65535/54980260303_45a03563ea_c.jpg)
I inadvertently undid the nut & bolt I put into the valve-lifter pivot hole, so replaced it, and used a felt washer to attempt to make it a touch less prone to weeping.
(https://live.staticflickr.com/65535/54980324329_ef0f1eeace_c.jpg)
Thinking about it now... I may add a lock washer or a nyloc to that....
I also realised that I hadn't offered up the cases with the mag-platform bracket into the frame and engine plates. So after a bit of swearing and cajoling I put the empty cases back in the mounts (I'm really not looking forward to that job when the engine is fully assembled!)
The bracket clears the plates nicely.
(https://live.staticflickr.com/65535/54980078261_232e9a4176_c.jpg)
(https://live.staticflickr.com/65535/54980324199_0b36ec7fe8_c.jpg)
I also took the opportunity to drill a little hole in the flange that protrudes from the output side engine case:
(https://live.staticflickr.com/65535/54980078241_7f5413953e_c.jpg)
The reason for that hole is that the engine oil drain bolt has a lockwire hole in it, and it was lockwired before (for good reason...), but Dad had the lockwire attached to a cut down penny washer that was under the bolt on one of the engine case screws. It just always seemed untidy, so - this way, the drain plug can be lockwired to the engine case itself and it's a neater job.
I've no idea what the flange is for - there are some numbers on there, but they're not the usual place for engine numbers, and I've not seen that flange on any of the engine diagrams or drawings I've seen - I think it "might" be an extra flange used on the stationary engines, eg ditch pumps, lawnmowers, generators etc (which are pretty much the same engine cases) to indicate... something!
I've also seen a few more engines in photos recently and they do often seem to have mag-platform brackets that aren't hugely chunky, so I'm going to go with the one I've made for now, and try to make some more progress.
Next job is make a few more paper gaskets for various covers and things that mount to the engine: the oil drain chest and vent chest covers both need one, and the cylinder base.
I was considering whether or not to try to "lap-in" the cylinder base to the engine cases, but I think I'll just go for a .4mm paper gasket. I've got some compression plates which should serve as templates for that gasket (they're normally used for reducing the compression so I won't be using them!).
Also need to heat-treat the copper cylinder head gasket, and I've got a few more spares too, so I may well just do them all at once, so the spares are ready to go. Trying to remember if they need to be quenched, or just left to cool down after I heat them to pink...
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The new rear-shock mount bolts turned up.
Exactly as specced:
(https://live.staticflickr.com/65535/54992498248_2edd40f06a_c.jpg)
(https://live.staticflickr.com/65535/54992578024_f992031ea1_c.jpg)
The left side:
(https://live.staticflickr.com/65535/54992498118_2de2997597_c.jpg)
With the pannier-mount in place, the shank does reach through to the outside of the mounting plate - exactly as measured. :)
(https://live.staticflickr.com/65535/54992498038_88efe74168_c.jpg)
Did the nuts up loose, just to hold things together for now.
(https://live.staticflickr.com/65535/54992316611_0cc4dbb1b9_c.jpg)
On the right side I can either spin the die down one of the bolts to make the shank the right length - or simply pack out the nut like this, with a couple of extra spacers.
(https://live.staticflickr.com/65535/54992614255_50ccbab90c_c.jpg)
This is how the pannier will sit, but it will have a secondary nut and bolt to hold it straight as well. :)
(https://live.staticflickr.com/65535/54992577749_4c8f8c81eb_c.jpg)
Should be much better, out of the way, and won't interfere with anything that moves. :thumbup:
I'll probably use tie-clips or something similar to prevent the bag moving along the axis of the bike (currently it can do that - but it won't fall off the mounting bar, the bar is too long). I'll get it all mounted tight and see what the best solution for that is later on.
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err, not been in the shop much over the hoidays... but managed to get in last week for an afternoon of shivering.
It's been preying on my mind somewhat that the measurements I took for the crank play weren't very accurate... so I decided that I really ought to do it properly with a dial guage. It was with this in mind that I entered the shop....
.. and pulled out the toolbag support bracket to finish off that job first. :D :roll:
So - first the next hole up needed a little file so that I could get a small bolt through it inline with the hole in the frame
(https://live.staticflickr.com/65535/55036904117_5011bd56c6_c.jpg)
Top view of the assembly in situ:
(https://live.staticflickr.com/65535/55037807231_4b4ccbb734_c.jpg)
Internal view: Washer and lock washer in place
(https://live.staticflickr.com/65535/55036904017_b8684d79c2_c.jpg)
Just a view of the main shock support bolt in place.
(https://live.staticflickr.com/65535/55037986388_5bb2c13b21_c.jpg)
And this is the tie-clip just stopping the toolbag falling forward or backward during riding (it can't fall off)
(https://live.staticflickr.com/65535/55038060389_ef18581465_c.jpg)
SO - with that done.... I remembered the dial guages...
I currently have 3: an imperial one and 2 metric ones - all bought randomly from jumble shows ( why I haven't just bought a new one from wherever.com is a mystery.... it had just never occurred to me.)
The imperial one seems to move and work ok, the Draper one seems to have a sticky movement, and the other metric one is ...well... just iffy.
So - in the best bulldog spirit of pressing forwards with the most important jobs....
I prevaricated again and started dismantling the sticky dial guage to figure out what the problem is.... :D
Looked ok at first glance...
(https://live.staticflickr.com/65535/55038150460_5c9d85a458_c.jpg)
However..... the eyeglass reveals all... (this thing (https://www.amazon.co.uk/dp/B0BLGD8D3G?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1) is turning out to be really useful! )
(open the photo in Flickr and you can zoom in.)
(https://live.staticflickr.com/65535/55038150450_0a20ab3716_c.jpg) (https://flic.kr/p/2rRwUCs)
The teeth on the main shaft are $%^&&ed. :roll:
So - instead of hurling the thing across the workshop in a fit of pique (it was tempting.... )
I calmly placed it to one side to see what was wrong with the other metric guage.
Hmm - something missing from here... I'm sure of it!
(https://live.staticflickr.com/65535/55036903842_c43d379a9f_c.jpg)
...
...
Can you see where this is going??
Can you?
I bet you can.
Yup !
FIXED IT!
(https://live.staticflickr.com/65535/55038060239_a436eae548_c.jpg)
:D :D
In addition... the knackered guage had a mounting lug on the back, and the newly fixed one didn't... so I figured that while one lug may not be as good as two lugs, it's still better than no lugs if lugs are to be needed.... (ahem) so I decided to fit the back from the dead guage onto the fixed one.....
which has 3 equally spaced threaded holes to secure the backplate.
The backplate with the lug... has 4 .... equally spaced ... holes.
<sigh>
FINE!
Get the drill out, carefully layer the 2 backplates so the old one can be used as a template..
(https://live.staticflickr.com/65535/55037806951_457c3d5841_c.jpg)
(https://live.staticflickr.com/65535/55038150310_c8c7d528d0_c.jpg)
And bingo!
A fully functioning, belugged, metric dial guage! (sorry, no photo. :P )
I also dug out a nice bit of ally hanging bracket (or something) to use as the "stand" for the guage - I can screw it to a bolt-hole on the cases easily enough.
I just need to reassemble the crank in the cases and figure out the arrangement of the guage....
Which will probably happen this week at some point... hopefully.
in the meantime... I'd be a lying little toerag if I claimed I wasn't strongly pondering the purchase of one of these (https://www.amazon.co.uk/Neoteck-Indicator-Magnetic-Saw-90lbs-Pull-Black/dp/B0DV39NPY1/ref=sr_1_25?crid=16PY5Q2DLSWW9&dib=eyJ2IjoiMSJ9.LWufQUaK4t7jIbTNis0WpDDfmOw4oNHlZM0vPmHweFF_FS426MuP4O17oe6lXTyRu_W8rdZ6aFmifU3lZiUmxHtjszagRR8g1MA9DOC0XQPM9IwSROLk46hAvJAi8YzVFAVh742vxGrVrx_I8-ZcTOxGynWdZ8rb0saKc026cX_04zlnCzIywR4nXBlpRApNFgtpWvpv-hcM-lgf0hEkLtt-iUhaExY2v09YPo14Z7nLJV1WyWUZP1cLm95NXO6A17uAT094LnlouI0Oy2LTIo74s1Yn4iA7ANuhsoa-wrk.5o0hbdBw5C-O7wypE0v89LOhdq9s-HPOa0ra25pWBWs&dib_tag=se&keywords=dial+gauge&qid=1768242117&sprefix=dial+guage%2Caps%2C148&sr=8-25)...
(or similar)
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Had a fun afternoon yesterday fiddling with the flywheel (dem tings are heavy)
Parts assemble!
(https://live.staticflickr.com/65535/55054766092_c8f1bc6d57_c.jpg)
First assembly:
Yes - I did you a little video!
(yes, the music was too loud... my bad!)
https://youtu.be/C0fcM7KXcNU
(I initially wanted to do a time-lapse video... but I ended up just posting it as is)
This is how the dial guage ended up being mounted - seemed to work well and enabled a consistent (mostly!) location:
(https://live.staticflickr.com/65535/55055925869_cc2f5a93cd_c.jpg)
It took a bit of fiddling to get the dial to zero properly (with the crank pulled all the way to the left).
(https://live.staticflickr.com/65535/55056022380_1be3f80c69_c.jpg)
Finding the initial float:
https://youtu.be/E4PKg67gMYo
Correction: the end float should be 0.012" - 0.015" (I made the same misread last time - because it's written in the booklet as .012" (the initial 0 is missing so I keep misreading it!)
Maths.
(https://live.staticflickr.com/65535/55055852038_17d0ff6bcd_c.jpg)
I initially chucked in 2 0.023" shims, one each side to see where that got me - theoretically, that should have been very nearly there....
(https://live.staticflickr.com/65535/55055675781_7f37941513_c.jpg)
The results:
https://youtube.com/shorts/MKNfHrS-ffc
I was also trying to get the conrod as central as possible - using the crank-case split line as the centre-line (an assumption - but I think a relatively safe one.... I hope!)
The polished crank means it's "relatively" easy to see where the conrod is
Crank pushed to left
(https://live.staticflickr.com/65535/55056023290_ba9ed0c171_c.jpg)
Crank pushed to right.
(https://live.staticflickr.com/65535/55054765762_3793551648_c.jpg)
I then added a 0.020 shim to the Timing side (right side) of the crank, and still had too much float (0.02xx something IIRC)
So I added a 0.010 shim to the left side as well
(https://live.staticflickr.com/65535/55054765537_cde899a076_c.jpg)
Too much??
(https://live.staticflickr.com/65535/55056022485_dde296dc2f_c.jpg)
Or just right?
(https://live.staticflickr.com/65535/55055674906_17c9000fa8_c.jpg)
(https://live.staticflickr.com/65535/55055674836_82b97d17ef_c.jpg)
While I pondered that...
I pulled out the compression plates that I have (which would sit under the barrel), which I was going to use as templates for the base gasket, and luckily had the thought to try them on the cases while I had the cases together.
They're not JAP.
Well - they might be JAP.... but they're not THIS Jap!
GAH!
I suspect they're from one of the other bikes... the Matchless maybe?
So - I also checked the spare head gaskets I found... and THEY'RE not right either! I could possibly use them... because while the inner diameter of the gaskets is larger than the bore, the outer diameter is considerably smaller than the outer diameter of the depression the gasket sits in! GAH!
I also have a box full of piston rings that I know are wrong (I think they're pre-war JAP)
So - I did a bit of tidying up...
(https://live.staticflickr.com/65535/55056022015_6c3f829fc8_c.jpg)
TBH, I think the float is now acceptable, so I dry assembled the piston and barrel (no rings or gudgeon pins)
(https://live.staticflickr.com/65535/55055925494_3b9082c2ed_c.jpg)
On a full 500cc engine with 15:1 compression... the piston should come right to the top of that barrel....
https://youtu.be/jHgrizea2ik
There's a fair bit of play in the small end - so I figured I could see roughly how central the conrod/piston is by gently lifting the barrel and observing the small end :
(https://live.staticflickr.com/65535/55055925309_07bb910941_c.jpg)
It looks ok to me!
Happy Bunny! Didn't need to buy more shims this time around.
Next job is to do some light grinding paste action with the barrel and the cases - the faces of the cases where the barrel mounts are a little lumpy, so I'm going to use some light grinding paste just to get the barrel and crank meeting faces "flat" which will a) help the paper gasket seal better and b) maybe possibly increase the compression by a gnat's chuff?? hey - every little helps! :D
After that - make up the barrel gasket and the oil-chest gasket (the volume under the timing chest where the oil collects for dispersal post use), and the gasket for the fitting under the oil-chest. I'm thinking I'll probably make up 2 or 3 of each: so I have spares for the future, and in case I have any accidents in assembly....
Then it's <gulp> time to start final assembly....
Although - I do still need to assemble the head and check the valves are sealing: using meths or paraffin this time! :D
I hope it gets a bit warmer soon.... at the end of every evening like this the ends of my fingers are freezing. :(
-
I'm starting to think that I really need to get in the workshop a bit more often - there's still a lot to do, and I'm definitely taking my time with things.
So - last night I went in and made gaskets. ... I know, it's soooo exciting! :D
Some of the parts that need gaskets, with existing old ones:
(https://live.staticflickr.com/65535/55062764804_f6f8c13114_c.jpg)
I started with the output side shaft seal plate gasket - this is a "non-standard" fitment anyway to slow down the loss of oil around the output shaft.
(https://live.staticflickr.com/65535/55061614892_88ff4c0bd7_c.jpg)
The outer and the fitment holes were relatively simple - but I need to break out the school-boy drawing tools for the inner circumference.
(https://live.staticflickr.com/65535/55062517421_5f68ff2cbd_c.jpg)
Note to self... for f*cks sake draw on the OTHER side....
(https://live.staticflickr.com/65535/55062517276_3e6a75f1f7_c.jpg)
But a reasonable finished product. :)
(https://live.staticflickr.com/65535/55062692333_6db4bf3ca8_c.jpg)
Next - the oil-drain chest cover.
(https://live.staticflickr.com/65535/55062517286_3c8aced4ee_c.jpg)
Should be functional:
(https://live.staticflickr.com/65535/55062868085_85766a91fd_c.jpg)
Funnily enough - the oil-collection chest gaskets can be bought, but this is an older one that's been used, and I can use it as a "master" template: it's a bit out of shape, but not enough to be a problem:
(https://live.staticflickr.com/65535/55062692193_9a984cc0f9_c.jpg)
(https://live.staticflickr.com/65535/55062868055_082237c97c_c.jpg)
Much easier to work on the non-printed side of the paper! :D
(https://live.staticflickr.com/65535/55062692138_595552af2d_c.jpg)
(https://live.staticflickr.com/65535/55061614497_cb2562dd6e_c.jpg)
With the old one that I pulled off: I'm going to leave this one as is, and not bother to trim out the internal "web" - it's not necessary.
(https://live.staticflickr.com/65535/55062692098_6e528c28b0_c.jpg)
The last gasket is the base gasket, but first I wanted to get the surfaces a tad smoother, so I dug out the fine grinding paste....
(https://live.staticflickr.com/65535/55062692048_936e0da457_c.jpg)
(https://live.staticflickr.com/65535/55062764304_7b8d40e731_c.jpg)
It's an improvement (I hope).
(https://live.staticflickr.com/65535/55062516831_5abe8bb1f4_c.jpg)
The initial circles I drew out with a compass, then tested for fit on the barrel
(https://live.staticflickr.com/65535/55062764209_e8c26173b5_c.jpg)
I then put the barrel onto the cases and marked the cut-outs for the bolts that tie the head & barrel down, then trimmed them out and checked the fit
I also trimmed out a smalle cutout on the inner of the gasket to match the slight cutouts which allow the con-rod to not-hit the cases.
(https://live.staticflickr.com/65535/55061614247_ddf673df82_c.jpg)
I've put them in "storage" for now, (under a couple of books as well), and will very likely make up another complete set, using these as templates.
(https://live.staticflickr.com/65535/55062516651_7aaba69617_c.jpg)
I then decided to make another fix:
The timing chain cover has another little cover over the mag-cog to allow you to adjust the timing without taking the entire cover off: you can lock the mag-shaft, then loosen the pinion nut and tweak it through a hole in the timing chain cover.
BUT - the threads on the tiny holes were tired - so I found some new set-screws with wide heads in the box of bits: figured out what thread they were M6 as it happened, ideally it would be nice to use Imperial all over, but there's other Metric threads on the bike so I'm kinda beyond caring at this point; re-cut the threads in the timing chain cover and hey presto!
(https://live.staticflickr.com/65535/55062764049_b490c208e5_c.jpg)
I cut the set-screws down to ensure they don't interfere with the timing chain
(https://live.staticflickr.com/65535/55062691788_f69d35263e_c.jpg)
And there'll be another paper gasket going under that cover to reduce any oil weep (the timing chain isn't lubed much, I don't think..., so it shouldn't be an issue really).
Actually quite pleased with the evening's progress.
Like I say - I'm going to make up another complete set of gaskets and will use that 2nd set for the build, and keep the first ones (the ones made directly from the mating faces) as the "master-templates". I may well find there's other places where a gasket might be useful, but we'll cross those bridges when we get to them.
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Got any spare enthusiasm going spare? I could really use some this time of year...
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Good job Rockburner - it's a reminder of how much work goes into an engine rebuild. Pleased that you found someone knowledgeable to help with the big end and flywheels. An expert can make a tricky job look easy.
I have a couple of little worries.
I fear that not fitting a valve lifter will prove to be a mistake. Even if you keep the compression well down starting without one might be a problem. I guess you'll find out!
My other concern is about the grease in the roller bearings on the mains. Grease isn't a very good lubricant on rollers, and I fear it might stop the oil getting to the bearing. It might be worth chatting with your JAP expert about it.
Should be running again soon? Good luck!
Leon
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Got any spare enthusiasm going spare? I could really use some this time of year...
HAH! I wish! Those last 2-3 pages of posts represent about 7 months of real time! ::)
I tend to manage about 2-3 hours a week in the workshop. I keep saying to myself I'll get in more, but never quite manage to do it.
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Good job Rockburner - it's a reminder of how much work goes into an engine rebuild. Pleased that you found someone knowledgeable to help with the big end and flywheels. An expert can make a tricky job look easy.
I have a couple of little worries.
I fear that not fitting a valve lifter will prove to be a mistake. Even if you keep the compression well down starting without one might be a problem. I guess you'll find out!
My other concern is about the grease in the roller bearings on the mains. Grease isn't a very good lubricant on rollers, and I fear it might stop the oil getting to the bearing. It might be worth chatting with your JAP expert about it.
Should be running again soon? Good luck!
Leon
Good points both.
The valve-lifter i removed has been broken for an unknown period, possibly years, and i was able to start the bike anyway, so I'll see how it goes. Now I'm much more familiar with the thing, refitting it is far less daunting if i decide I need it.
Yes I am aware of the dubiousness of using grease on the rollers. I'll be cleaning them off and soaking them in R40 before final fitment. Using the grease does help to keep the assembly together during the repeated assembly/disassembly process while getting the shims sorted out. Its all good.
Thank you though for pointing out those concerns, this is my first complete rebuild of anything, and the deepest I've ever gone into the bowels of any engine, so there's lots I know I don't know, and even more that I don't know I don't know.
But the list of things I know is growing, which is good!