Im currently Doing a rebuild and have a set of Hepolite 040 pistons Possibly High compression.

I have been told that there quite a good piston. Im just alittle curious to see what other people have thought of them through experiance?

Really good or average?

regards Matt

I have built a few 1275 motors with Hepolites.
21251 (8.8:1) are cheap but not very strong, they are OK for a stocko rebuild (non-S).
21253 (9.75:1) are a better, stronger piston, similar to a Hypatec but more expensive. I recommend get Hypatecs instead if you are buying new, they are heaps cheaper. Can also get these in 73.0mm and 73.5mm.
If you are going racing or building a big HP weekend warrior, check out Russell Engineering's pistons.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

they are 20747's

the also have stamped
413 and AE


if that says anything

they were out of my dads old engine which was built for a racing purpose. it did about 2 hours of running time

As the good Doc has said.....Go the Hypatecs or get a set of GR pistons if going over +60thou best you speak to the man first as to your requirements.

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http://www.youtube.com/watch?v=nDMkVq1jRGU

The main problem with Hepolite pistons as I see it is that you are limited in the type of piston rings you can use, As far as I know only Hepolite rings fit the piston.
They are not Chrome or Molly top rings and the ring gap is way to large straight out of the packet.
If you chose to use Hypertec pistons you have a far greater choice of quality piston rings from different manufacturers, eg Grant or Hastings.These companys offer a choice of a cast, chrome or molly top ring which can be gaped to the correct size before fitting.
Dave

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David Vazard says that 20747 is a forged piston with a 9.7CR 6cc Dish Excellent High Performance Race Piston

Will take Hastings Rings

Nippon rings fit the Hypatecs too, I run them in my 1412 stroker. GR uses these in his own brand pistons.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

20747 is "Econoguide Powermax" piston. Hepolite were the only piston manufacturer in the world to make this style of piston. On the thrust skirt of the piston there were 3 raided pads (less than.0005" high) that contacted the bore. These pads were formed when the piston was forged. This cut down friction.

You could not see these pads when the piston was new - only after the engine had been run for a couple of hours.

An extremely high quality piston.

Hope this helps.

There you go Leema,
Looks like you have a trick set of pistons there




Thanks for the tip on the Nippon Rings Kevin.
It's always good to have another option

Dave

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Trick set??

He means VF Good....

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I think i have found those 3 pads you talked about