Misc: Everything Else Standard Comet Special

Oldhaven

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I am underway on what will likely be my last motorcycle project and two weeks ago a set of 1951 Comet cases and covers arrived from Australia. The Comet was originally delivered to Liverpool, so they have traveled a bit. Mal Hewitt bought them several years ago thinking he would build a Comet special, but his time has been otherwise occupied it seems. I will probably use this new thread to ask a few questions, and here is the first one. The crankcases at one time passed through the Horner's shop for some repair work on the main bearing bores, but I am puzzled by the spigots for the push rod tubes. They are threaded. Does this modification ring a bell for anyone? Perhaps some clever attempt at sealing?

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Bill Thomas

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I am underway on what will likely be my last motorcycle project and two weeks ago a set of 1951 Comet cases and covers arrived from Australia. The Comet was originally delivered to Liverpool, so they have traveled a bit. Mal Hewitt bought them several years ago thinking he would build a Comet special, but his time has been otherwise occupied it seems. I will probably use this new thread to ask a few questions, and here is the first one. The crankcases at one time passed through the Horner's shop for some repair work on the main bearing bores, but I am puzzled by the spigots for the push rod tubes. They are threaded. Does this modification ring a bell for anyone? Perhaps some clever attempt at sealing?

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Can't help you Ron, But does a standard pushrod tube seal fit what you have, In which case you may be able to drill the threads out and go back to standard ?.
Good Luck , Bill.
 

davidd

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Robert Watson used an O-ring. It would be interesting to know if he still uses it. It was a lovely job of cutting an O-ring in an aluminum tube and pressing it into the case. I thought it was brilliant because you could move the push rod tube up and down without yanking the seal out of place, which can happen with the stock set up.

David
 

timetraveller

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It looks to me as though they designed something which would go round the pushrod tube and compress an 'o' ring when it was tightened down. I can see that this would make a better seal than the original set up if there is lots of crank case pressure but for normal use the original set up works well if the tubes and the seal housings are in good order.
 

Oldhaven

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I think I have figured out what the modification is. I mentioned that the cases had been at the Horners for repairs, so I took a look at pictures here of one of their other projects and found this. The thread looks like a metric 22mm and the screwed or pressed in fittings in the cases of the Rapide must have some sort of seal like TT mentions above. I can almost see an o-ring or oil seal if I zoom in. they must have been experimenting with something like that. I wonder if the slight differences in angles of the tubes is compensated for. It also looks like the upper gland nut has been modified.

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Cyborg

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What's your plan for a frame, forks, brakes, etc? I have a set of Comet cases and have been mulling over what to do with them. One thought is a spine frame and some Japanese forks and brakes. Would that get me drummed out of the VOC?
 

vibrac

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VOC Member
What's your plan for a frame, forks, brakes, etc? I have a set of Comet cases and have been mulling over what to do with them. One thought is a spine frame and some Japanese forks and brakes. Would that get me drummed out of the VOC?
It didnt seem to affect the standing of a certain Swiss Gentleman:) of course if you are from an EU country you should be more worried about trying to get it registered rather than the aprobation of a few Vincent owners, but then again a certain French Gentleman seems to manage it....:cool:
 
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