Incomplete pistons on eBay.

[Tony Fearn]

http://www.ebay.co.uk/itm/2-Jowett-std- ... 2ee529612f
If I remember correctly, and it's a long time ago, Roy Braddock told me that a standard 8hp piston was the same as a 7hp 60 thou oversize piston.
I'll bet George knows.
These are on eBay and are missing some parts.
Tony.

[george garside]

I am pretty sure that's right Tony.

If anyone can calculate it from inches the standard 7hp bore is 2.970'' and the standard 8hp bore is 3.0325 so the question is does 2.970'' plus 60 thou equal 3.0325''

I would be wary about overboring to +60 (official overbore being +40)

george

[k. rogers]

If you take one from the other it equals 0.0625 or 62.5 thou, so it would mean boring out to just over the 60 thou! George, I always thought up to 60 thou was permissable for the bore and 40thou for the crank - I will have to consult my manual.

[george garside]

from The Jowett owners maintenance handbook 1935 - 1939 ''Cylinder reconditiiooning all models. the permissible maximum oversize is .040'' in stages of .010''

I once had one that broke the non water jacketed part of the cylinder whilst in motion about 2 inches from the flange. When examined it was overbored to +60 thou. Hence my note of caution!

george

[k. rogers]

Sounds like the only way for the Weasel, when the time comes, is to sleeve it back to standard size - she's already been bored out to 50 thou and has done an estimated 20 thousand miles (17,000 of them with me!) with the current pistons.

[PAUL BEAUMONT]

Those pistons concerned me as they look like Bradford ones not 8hp, but the bottom ring looks wrong - I suspect that they may be stationary engine pistons. We should not be influenced too much by what it says on the box. There has been plenty of time toy substitute!

Paul