eCtune

ok, nothing to do with eCtune but I want to know the best ring end gap for my new engine. Its a bored 81.5mm stock sleeve B16a2 with JE pistons. It is gonna be used on track days with a GT28RS turbo @ 15psi on it. I read a lot of things like .020\" for the top and second ring, and something bigger for the oil rings. Some any comment about this?

i ran across this link a few days ago. http://www.laskeyracing.com/shop/ringgap.htm

Evans tuning Engine building http://www.youtube.com/watch?v=mpy_By5aIxM http://www.youtube.com/watch?v=MtTXA9_a ... re=related

Stick with the formula that is provided from the ring manufacturer, they give that formula based on the expansion chars of the material being used. As for piston to wall clearances I've seen and run piston to wall clearances of .020 to .045.. In my experience, a JE or Weisco piston does not expand enough to need .030+ sized clearances, at least not in a honda motor. I know Jeff Evans and Tony Palo all say that if you run less than .035 or so you'll have problems. The last 3 turbo motors we've built have been at .025.. 2 @ 400-450HP and 1 @ 750+HP, and neither of them have had any issues. Actually in my opinion those have been some of the best running motors we've built. I've seen and tuned motors with larger gaps, the only advantage I have seen to a larger PTW clearance is a few more HP at high engine speeds, but at the cost of ring life, AND I've seen running large PTW clearances cause the piston to rock more in the sleeve and wear the sleeve alot more on the front and back. Just some things I've noticed.

any of those a vitara motor by chance, or were they forged pistons?

hehe, no all forged pistons..

Thanks guy's! JE's manual has a big variety of setups and also a lot of end gap advisements. Without this info I would have made the gap too small I think. Because it is gonna run only 1 bar I stick to 0.02\" Thanks again!