Author Topic: A10 Pistons again  (Read 444 times)

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Jackson

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A10 Pistons again
« on: 04 January, 2018, 16:30:28 »
Sadly, I can't get away with using my existing (+060") pistons and now have to reline the barrels and get new pistons for my '53 Flash.
I realise that the lowest compression I can get is 7.25:1, but these mostly seem to be new Hepolite which I hear bad reports of (or at least the rings).
IMD are available complete with new liners, they say they are 5g lighter than the original, won't this mean I have to rebalance the crankshaft?
I would value any thoughts on good pistons and where to get them.
Thanks in advance,
 Adrian

JulianS

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Re: A10 Pistons again
« Reply #1 on: 04 January, 2018, 17:26:28 »
I doubt 5 grams per piston will have a significant effect on engine balance, your existing pistons may not be original BSA and if they are the old British Hepolite (not to be confused with new hepolite) then these were somewhat more sturdy in construction and heavier than the original BSA.

I have used the new hepolite, pistons seemed OK but new hepolite rings poor quality mine failed to bed in after just over 1000 miles when I gave up with them and after having the cylinders honed fitted Italian GPM which soon bedded in.

If linering the barrel in my view the lipped at the top liners make a better job than the unlipped. Others may disagree.

Linering can be an expensive job.

Bess

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Re: A10 Pistons again
« Reply #2 on: 04 January, 2018, 17:37:53 »
Hi,
      I agree with the use of lipped liners, they don't pull down if the piston seizes. Try SRM for pistons.

Best wishes...

Jackson

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Re: A10 Pistons again
« Reply #3 on: 04 January, 2018, 22:51:46 »
Thanks very much both.
Iíve just checked and the pistons supplied by SRM are the IMD ones referred to above.
They look like a good choice.
IMD also produce liners but Iím not sure if they are lipped, most donít seem to be, but Iíll find out.
Regards and thanks again.
Adrian

KEVZEBOY

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Re: A10 Pistons again
« Reply #4 on: 04 January, 2018, 23:06:07 »
itís the Hepolite stuff in yellow boxes that is to be avoided, by all accounts. You can still get UK Hepolite rings which are good and a totally different thing confused by the same name.


JulianS

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Re: A10 Pistons again
« Reply #5 on: 05 January, 2018, 09:13:38 »
The original Hepolite also came in yellow boxes ...................

You still sometimes see new old stock Hepolite pistons and rings offered.

JulianS

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Re: A10 Pistons again
« Reply #6 on: 05 January, 2018, 09:48:44 »
Photo showing original Hepolite ring set packing