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Hepolite piston

Posted: Thu Aug 11, 2011 1:03 pm
by charles.bulloch
Hello all!
I have a NOS piston, Hepolite 5045, +20. What will the compression ratio be with this in my alloy head VH?
I am seriously considering relining my barrel to take this piston, to replace the +60 GPM 13246 which I am using, as at over 70mph I really have to hang on!
Can I expect more speed with the 5045?


Posted: Thu Aug 11, 2011 3:28 pm
by dave.owen

Is the piston Flat , dished or domed

these are usually 6.8:1,6.2 or lower ;1,7.5;1


Re: Hepolite piston

Posted: Thu Aug 11, 2011 5:06 pm
by charles.bulloch
Hi, Dave, its flat.


Re: Hepolite piston

Posted: Fri Aug 12, 2011 9:22 am
by adrie.degraaff
A flat piston is not good for speed if with an alu head.

Posted: Fri Aug 12, 2011 9:16 pm
by robin.parker
But, the Hepolite piston is probably the correct weight for the engine's balance factor, so you'd expect a smoother motor at high revs and would likely be able to go quicker.

Posted: Fri Aug 12, 2011 11:08 pm
by Simon.Gardiner
It's a 7.5:1.
If the GPM really is 7:1 (according to google) then I wouldn't think it would be any quicker, but it might be smoother if it's lighter.
Having said that getting the bottom end set up really well seemed to have a big effect on mine.
(How odd, there was a 5045 just like that on ebay not very long ago!!)