Thread: Ring gap for boost?

yes. On a larger bore you will need slightly larger gaps. 86.5mm you could still get by on the 17 and 19. Any larger than 87mm and you prob would wanna go 18 and 20.

I always rotate my rings according to the specs, but every time I've torn the engine apart the rings are NEVER lined up even close to the factory rotation. I honestly wonder what the big deal is with lining up the gaps in that way if they just move around. I guess maybe engineers are hoping they will seal better from initial start through 100K miles. I just don't know.

intresting that they do indeed move.

ive seen plenty of builds on the net, on tv and a few pistons in person, and have always seen people do gap orientation.

maybe its just for intitial start up like you sad.

stratton.

I picked up a feeler guage lastnight so i may dive into that bottom end tonight, time permitting or course. oh and one more question....Are the main caps interchangable? i accidentally got them mixed up when i tore down that motor months and months ago and cant remember which one goes where but does it honestly matter? Thanks guys!

Yes it matters. They are numbered 1-5 from the front of the engine to the rear (flywheel). On the end pieces (1 and 5) the machined end faces inward toward the crank, not outward.

It is another 30 min, but you want it to be right.

Thanks man you are a big help!

Yeah definetly matters on the main caps. Just put them in order with the top of the number pointing towards the front of the block.

alright so i just measured my rings and seems like 3 of my bottom rings are measuring .020 is that acceptable? tops are all consistent at .017 gaps. 86mm bore by the way.

If you mean the 2nd ring, which sounds like, then .020 is a bit on the big side. The top is where it's at though, and at .020 the second one looks like it is setup for big boost. You should be just fine.

yes, im running 86mm bore, i dont have any blow by that i know of, motor has around 2500miles on it right now, i would personally use this ring gap again, i know some people run .015 and .017 and get away with it fine

Using NA specs is perfectly fine for a boosted motor. Even at .015 and .017 I'm sure you will be just fine unless pushing 30+psi boost. Stock DEs come with tight specs, and although the pistons don't expand like the forged stuff, they don't have any issues running until things melt.

But at .015 and .017 it is going to be as far as I would take it.