I have forged 2618 aluminum alloy pistons in 84.5mm and am looking for a gap end spec. I see of course on JE's webpage their piston install manual (http://www.jepistons.com/pdf/piston_instrc2618.pdf) where they give their standard formula of 'Bore x .0050" top, and 'Bore x .0055" second for street moderate turbo. I also see on their FAQ

8. What kind of ring end gap should I run?

We supply ring spec sheets with all of our pistons. If you misplace it, or would like specific gap specs for your combination, give us a call and tell us how your using our pistons so we can help you with gap specs.

My piston's did NOT come with a ring spec sheet. I used their default formula and came out with:

Top: .017
Second: .018

I'm gonna go ahead and start filing in a bit, but what gap spec are you guys using for comparison?

84.5mm b18c darton pro, 10-15lbs (20 max) on gas.

Also, on the SRP ring sets it's very clear which is top and second as they are marked JE1, JE2 etc.. On my rings, they both are N150..but I believe the bronze colored ring is second. Thanks.

 

The spec sheet that came with mine for a D16Y8 said bore x .006 for nitrous and turbo.

 

Looking at your link, looks like you have SRP pistons. SRP pistons are 4032 alloy... I assume the ring sets have different specs.... Thanks anyways..anyone else with JE 84.5mm turbo ring end gap spec?

 

Yes that is true, sorry I didn't mention.
on me, I wasn't thinking.