arc_55

srp/je recommends minimum .0022"-.0028" and an additional .001" to .003" for endurance, supercharged, turbo and nitrous engines.

The srp 4032 alloy pistons i am looking at have a lower thermal expansion rate i am curious to know what others have used for PTW clearance on this alloy of piston.

I am using these on a 400whp z6 and 400+whp lsvtec

I am using this alloy as they are going in daily driven cars and with the lower thermal expansion they will be less if not audible at all.

Your insight/experience/advice is much appreciated!

Thanks

d16z6Tcrx

every srp piston ive heard is a little noisey until warmed up. im using a 4032 piston with a .0045 ptw. i wont car too much about the noise as long as it seals.

arc_55

I am using the 4032 alloy so there can be tighter clearances say then other alloys available. I am not so worried about the noise i am curious more about ptw clearance with this alloy.

Thanks for your insight!

at what power level are you at with .0045" ptw clearance? much blow by? bore size?

BigMike0147

I'm getting ready to get some Supertech 4032 pistons myself, and I just finished contacting them directly about clearances.

Their spec sheet recommends a minimum PTWC of 0.00315" for their piston, and subtract 0.0004" if you're going to do a break-in. So I had them clarify "break-in" since everyone feels differently about it, and this is what I got....

"For the first 600 miles try to avoid full throttle acceleration, keep it below 5,000 rpms and avoid long periods at the same speed."

Maybe this info will help some others....

d16z6Tcrx

im breaking mine in boosted. pump gas street tune then off to NRGTech for some q16