Author Topic: 66 Bonneville  (Read 289 times)

Offline Grunt

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Re: 66 Bonneville
« Reply #15 on: September 12, 2018, 04:43:42 PM »
Have you got two studs with nuts on between the two rocker covers in the middle web of the head.

Offline Oggers

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Re: 66 Bonneville
« Reply #16 on: September 12, 2018, 07:15:35 PM »
Clarifying further - hopefully....Barrel is stamped E6305. and some old pistons which I have since found, and for which I have been assured went within said barrel are @70mm diameter.  Thus it appears I have a 650 barrel - though it is squared off at the RH front of the flange.

Head - One stud and nut only between the two rocker covers, but where the other should be about an inch rearward, there is a circular blank off in the casting itself. Definitely only one oval shaped finned rocker cover for both exhaust ports and similar for inlet ports. I know the head of a 140 should have 10 studs, but clearly the barrel being a 650 would have only had the 9. That said, why does the head not have the hole for the 10th stud rather than a cast blank off....all very odd!

Offline mini-me

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Re: 66 Bonneville
« Reply #17 on: September 12, 2018, 08:26:06 PM »


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That said, why does the head not have the hole for the 10th stud rather than a cast blank off....all very odd!

No mystery, common enough if casting was meant to do two different years, probably a later replacement.

Personally I don't like the sound of your engine, but that's just my cynical mind; if it was up to me the engine would be on the bench in bits being checked out now.

Offline Oggers

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Re: 66 Bonneville
« Reply #18 on: September 12, 2018, 08:52:30 PM »
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No mystery, common enough if casting was meant to do two different years, probably a later replacement.Personally I don't like the sound of your engine, but that's just my cynical mind; if it was up to me the engine would be on the bench in bits being checked out now

Ok so is it a T140 head or a T120?

Engine rebuild documentation is fully comprehensive and work was undertaken by Peter Palmer - of some repute I believe in the Triumph world. No issues there I feel.


Offline Grunt

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Re: 66 Bonneville
« Reply #19 on: September 13, 2018, 07:57:25 AM »
Could the tenth hole be a well made plug rather than a cast in blank. Come to think of it, for that size hole I doubt it would have been incorporated in the casting.

Offline mini-me

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Re: 66 Bonneville
« Reply #20 on: September 13, 2018, 10:05:02 AM »
you seem to have missed the point, same casting would do a 9 or 10 stud barrel just drilling as necessary.

If their is any other difference its probably internal.
Never heard of this Palmer bloke, lots of Triumph 'experts' out there, one or two may even have been born before Triumph went bust.
Me, I have owned ridden and worked on Triumphs since 1965, seen most of the bodges but there is always more.

Some pictures would be a great help, does it have push in or stub fit at the head?

Send pics of the muck oozing out the gaskets for a gloomy assessment. ;)



Offline Oggers

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Re: 66 Bonneville
« Reply #21 on: September 13, 2018, 11:45:49 AM »
Quote
you seem to have missed the point, same casting would do a 9 or 10 stud barrel just drilling as necessary.

If their is any other difference its probably internal

No, since reading around somewhat you are correct in that the same casting appears to have been used for both. 10th hole cast-plugged for the then 120, drilled open for the 140. What I was getting at is that this head is different to the head used for a 66 120 - slightly larger exhaust vv head, stellite tipped vvs and possibly slightly different compression. Considering I have what appears to be the correct barrel, does this give rise to concern? I would have thought not...... 

No leaks anywhere, and I have no issues with the guy who did the rebuild. 
« Last Edit: September 13, 2018, 11:47:28 AM by Oggers »

Offline mini-me

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Re: 66 Bonneville
« Reply #22 on: September 13, 2018, 01:06:39 PM »
Why not ask the Palmer guy who built it?
seems the obvious way to get a definitive answer?

Quote
since reading around somewhat you are correct in that the same casting appears to have been used for both


It's good to know that that the internet agrees with my 50 plus years of mechanic-ing Triumphs ;)  much of it for a living.
« Last Edit: September 13, 2018, 01:09:34 PM by mini-me »

Offline Oggers

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Re: 66 Bonneville
« Reply #23 on: September 13, 2018, 03:20:15 PM »
Since asked, he thinks not.

Internet? I read books or manuals, I skim the internet.