T100R

[Marky]

Right Rev-I'll go talk to the engineers!

[twolitre]

Reverse the valves in the guides, so the head touching the seat is not a problem. If you can feel ANY rock the valves and/or guides need replacing (most probably guides).
Too much inlet wear will increase oil consumption by burning. Too much exhaust wear will increase oil contamination and increase oil consumption by loss through the breather.
As for the bush, Tinning was offered as a possibly acceptable solution depending on damage/wear. Replacing the bush with a new one carefully sized is obviously the better solution and is so obvious that comment is really unnecessary.
It will be interesting to view the Loctite response. By the way there is a short video on the loctite site about re-fitting a key to a worn keyway. It looks though as if once fitted, it is there for good, which might compromise future dismantling. Reversing a woodruff (half moon) key will not work.

Addition.
Sorry I misread your post about tappet wear thinking the part about "guide wear" referred to valves. My apologies.
Any tappet face wear or rock will affect valve timing. Some wear is inevitable. The only way to determine what is too much is to refer to a valve timing diagram for that engine and to check using a timing disc and Dial Test Indicator (DTI). Rather awkward with the engine incomplete because allowance has to be made for rocker clearance.  

[Revband]

OK I have re read your post regarding worn tappets, and now after Twolitre's comment I am not sure if you actually mean the tappets or the valves and guides, if the tappets then my previous comment applies but if you mean the valves and guides then Twolitre is correct.

[Rex]

I've been around the C range Triumphs for many years now, and as I've previously said, I've never yet encountered a main bearing bush which as nipped up so tight that it's turned in the cases. The bush is usually lubed enough/loose enough that that wouldn't happen, but should there be some total oil failure, the harder-working D/S big end would be suffering too.
Not saying it hasn't or can't happen, just that it must be rare, so that said, if it's happened to you and you don't feel comfortable with a suitable repair, I'd let a machine shop have a look at it for you.
A bush like this turning in the soft ally cases could have done a lot of damage, and Loctite or tinning may be unsuitable for this level of repair. Never heard of any over-sized O/D bushes for this application either; it's not a usual wear problem, but a damage repair issue.
Any eventual replacement bush will need line-reaming to suit too. It's possible to get away without reaming (sometimes) if it's just  new bush going in, but if your cases need machining to take a custom-made bush it'll be essential, and that's something else a machine could do relatively easily, but you couldn't do at all without the proper tool.

I don't get the bit about "hand sliding fit" though. The bush is a very tight fit in the case, and needs lots of heat to expand the cases to remove it. We are talking about the same bush here, aren't we?
Equally "turning the half-moon over".... eh?
 

[Revband]

I have to agree fully with Rex's comments, this is no place to compromise, a full and correct repair is essential.

I have in the past had experience of this bush turning in the case on this occasion I line reamed the case as the hole had worn centrally and evenly I then turned up a new bush allowing two thousands of an inch oversize for the interferance fit, this bike has done 15000 miles since the repair and it is fine. 

[Duppy Conqueror]

Hi guys it would would be madness notto do the job properly we are at present waiting for the new bush to arrive in the meantime we we will be trying to get some quotes for the work from the engineering firms mentioned at the start of this thread

[Duppy Conqueror]

ok this post was originaly about end float it it is 25 thou the new  bush is goin to make it 17 coz the shoulder on the the bush is 8 thou thicker than the old one.

[Revband]

Hi Duppy

It is your other thread which is regarding end float, get's confusing with more than one doesn't it?.

[Rex]

ok this post was originaly about end float it it is 25 thou the new  bush is goin to make it 17 coz the shoulder on the the bush is 8 thou thicker than the old one.

Shouldn't be any problem with that, but how did you repair the bush location in the end?

[Duppy Conqueror]

The bush hasn't been fitted yet. It is still out off the case till the crankshaft has been reground but the diameter of the new bush is 4 thou up on the old one and wasn't going to go into the case without some force, the machine shop that is doing the other work is going to fit it and make a slieive to fit if they think that the new bush is not a tight enough fit. I full confidence in them they jave been working on bikes since I was in my teens and the guy's eyes lit up when we brought are box of bits up so I dont think they will do a botched job, should know with in a week.

[Rex]

I'm confused again...

If the new bush is 4 thou up on the old one and won't go in "without some force" why would the other machine shop need to make a sleeve if it isn't tight enough?
Sounds more like they'll be reducing the O/D of the new sleeve, but that would be an easy job.

[Duppy Conqueror]

A sleeve hasnt been made just talked about as a possibility, when we got the new one it wouldn't go in without heating the case up I assumed it would be lose like the old one.

[Revband]

As Rex says, this is becoming one confusing discussion,

It appears that you have now bought a proprietary bush and not had one made, if this is the case the bush will need to be two thou bigger on the outside diameter than the hole in the case, to fit the bush no force is used, the case should be heated in an oven to 180-200 degrees C and the bush should be left in a freezer to cool, the bush will then drop straight into the hole and should be left alone till the case cools.

[Duppy Conqueror]

Ok when I said "force" I meant the old bush can be taken in and out quite easily at room temp. Under the same conditions the new but the new bus wont, so the case needs to be heated to get it in so that looks like a good fit to me. I  may have been a bit alarmist over how bad things are and probably tried to paint the worst scenario. Like wnen I posted about endfloat it started out a mile but was only 25 thou. and for some reason I can't understand  why the wear on the bush, as a whole seams to be more than the aluminium the shoulder on the old bush is worn eonugh to give 25 thou. endfloat but the new one brings it down to 17 thou. on measuring the two shoulders with a mic. same for the od of the bush 4 thou. more than the old one.

[Revband]

Duppy

It's a strange fact of life but when a hard and a softer metal are rubbing together it is always the hard metal which wears.

A good example is the Gudgeon pin or wrist pin as our American friends call them, the pin always wears before the little end.