LS2 / 403 Piston Recommendations

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Feb 14, 2019 | 06:25 AM

hiltsy855

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LS2 / 403 Piston Recommendations

I'm building a 402/403 using a new GM LS2 block for my '02 Z28. The car will be a Power Tour / fair weather driver with a road race thrown in a few times in the summer. CR will be ~11.7:1, no nitrous or boost. I'm using a Compstar 4" stroke crank and 6.125" rods. I'll bolt-on my existing PRC LS6 heads. For pistons I'm leaning towards a 4032 flat-top forging like JE/SRP #279585. I would think reduced piston-to-wall clearance will keep the piston from rocking at the bottom of the stroke. I don't need a noisy oil burner. Let me know what you guys think of these pistons and / or anything else you recommend.

Feb 14, 2019 | 08:34 AM

KCS

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Quote:

Originally Posted by hiltsy855

Either 2618 or 4032 works fine with 4" or more stoke. The piston rock issue was caused mostly by improper skirt design back in the day. Modern pistons, like the ones from Wiseco and Summit, don't have those problems. You just have to make sure to deburr the sharp edges at the bottom of the cylinders to avoid skirt damage and they'll last.

Feb 14, 2019 | 11:01 AM

hiltsy855

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I wish Wiseco made their Pro Tru Street piston for my application. The Summit line looks interesting.

Feb 15, 2019 | 06:27 AM

hiltsy855

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KCS - Are you saying the JE / SRP pistons I referenced have the "improper" skirt design?

Feb 15, 2019 | 12:02 PM

KCS

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Quote:

Originally Posted by hiltsy855

KCS - Are you saying the JE / SRP pistons I referenced have the "improper" skirt design?

I don’t use JE/SRP so I wouldn’t know. All I’m saying is that the skirt design is more important than the material selection. Brian Nutter at Summit Racing has a very good explanation of how it all works.

https://www.onallcylinders.com/2019/...s-engine-easy/

Feb 15, 2019 | 12:45 PM

pantera_efi

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Racetech Forged pistons = OK

Hi 855, I can supply a Forged Racetech piston (4032).

I have done this often with a 4.0" shaft and 6.125" rods.(flat top piston)

A TOP Quality part at a FAIR price.

Lance 949-250-1797