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LS2 / 403 Piston Recommendations

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Old 02-14-2019 | 06:25 AM
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Default 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.
Old 02-14-2019 | 08:34 AM
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Originally Posted by hiltsy855
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.
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.
Old 02-14-2019 | 11:01 AM
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I wish Wiseco made their Pro Tru Street piston for my application. The Summit line looks interesting.
Old 02-15-2019 | 06:27 AM
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KCS - Are you saying the JE / SRP pistons I referenced have the "improper" skirt design?
Old 02-15-2019 | 12:02 PM
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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/
Old 02-15-2019 | 12:45 PM
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Default 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
Old 02-15-2019 | 02:58 PM
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Great info. Thanks guys!!!
Old 03-17-2021 | 12:12 AM
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Originally Posted by hiltsy855
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.
hey man I don’t know how else I can contact you so this is my best shot I’m building a 8.8 for my 3rd gen camaro and you used to sell a ta mount on eBay but I didn’t buy it in time the post is no longer available is there anyway I could still get one my emails nickrobns@gmail.com




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