viton o rings

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charles.bulloch
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viton o rings

Post by charles.bulloch »

Hi, all.
As it seems impossible to get push rod oil seals to fit, I an considering buying 8.4 mm viton cord with which to make o rings. This will have to be cut and glued. Will the glue withstand the temperature of an iron cylinder head?

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Re: viton o rings

Post by nevhunter »

I'd stick to a conventional type "O" ring made of viton and concentrate on having the right size and something to hold it in the right place. The "Originals" (thyrco) used to crush in and wear the alloy pushrods quite badly. Nev
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Re: viton o rings

Post by pete.collings »

Why not try the mod to lessen oil loss in this area, it consists of an aluminium carrier to fit in the cylinder head recess, with a viton O ring as a seal, adjusting the crush on the O ring to around 25 thou. I believe Triumph twins used a O ring to seal pushrod tubes.

The details of this mod, including dimensions, are somewhere on the forum, and although I cannot find them at the moment, I am sure someone else will advise.
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Re: viton o rings

Post by fpassmore »

I believe this is the mod you are talking about. viewtopic.php?f=7&t=11836&p=83538&hilit ... eal#p83538
'51 SQ4, '56 NH, '56 VH, '37 VH500 Red Hunter, '56 SQ4 (basket case), '49 Sq4 (basket case), '48 A7 BSA Twin, 12 other BSA's, 9 Norton's, 2 Triumph's, 3 Ducati's and 3 Japanese. Just crazed is all my problem is.
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Re: viton o rings

Post by JohnnyBeckett »

hi i use a good hi temp black silicone on the stranded seals and i have been OK with no leeks :D
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charles.bulloch
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Re: viton o rings

Post by charles.bulloch »

Thanks for the answers, folks. The suggested mod. is for the alloy head, I have an iron head.
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Re: viton o rings

Post by fpassmore »

Missed that, you did say iron head. I would probably go for a good quality sealant applied to the o-ring.
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Re: viton o rings

Post by Roger Gwynn »

Draganfly are belatedly altering the material of the push rod seals to withstand the high temperatures that make the existing material go rock hard after a few thousand miles.
Roger Gwynn, Membership Secretary, curator of the Machine Register and the works drawings. Director of Draganfly Motorcycles, Craven Equipment and Supreme Motorcycles mostly retired.
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Re: viton o rings

Post by nevhunter »

On the iron head I've stuck to original looking things wherever I can get them. Rubber is useless as it just expands and goes soft. I don't think round "O" rings would work especially at the lower ends where the rubbers go deeper. Not a lot of help but that's it from me. I'm keen to hear of other suppliers. Nev
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