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Hi guys i am in the process of rebuilding my rb30 i have got myself a set of je pistons 86.5mm(3.4055')and they recommend a .0045 piston to wall clearance. The machinist said he has put the bores right on 3.4055". When i measured up the pistons it shows i will have from .0046 -.0047 p2w across the set now it will see mid 30psi on e85 and be spun to 8200ish rpm the application is mainly street with some trips to the strip. The last set of pistons that were in the motor were a short skirt mahle piston made from 4032 with around. 004 piston to wall clearance and it had a fair bit of piston slap even when warm and drove me up the wall. The new je piston are a 2618 material so they will expand alot more once warm i am trying to lower the piston noise with out having problems with wall clearance.
I don't have any first hand Experience with JE, although I do have experience with Wiseco, last time I checked both pistons brand uses the same Material, I normally run 45-47 with Zero Piston slap although my engines are Honda, you shouldn't have any concern regarding piston slap with current setup
You should be fine with 0.0045" on a 2618 piston for your application. 0.004" is pretty generous for a 4032 piston which I'd say is the cause of your piston slap.
Thanx for the replys guys i thought that it was a little to much for a 4032 piston. Just wanted to hear from someone that had some experience with p2w to find out if it would slap around again with the 2618. I will run with the 4.7 clearance thank you for putting my mind at ease