I am re-building a 2002 GM LQ9 6.0 LS motor
Using factory rods/pistons and stock bore
my machine shop supplied a set of Sealed power piston rings #E-921k
the piston ring end gaps measured:
Top rings all between .022-.025
2ND rings all between .025-.027

Will these gap ranges be acceptable? I keep finding mixed info stating anywhere from .018 to .035 ranges

I am stuck in the middle of this build trying to find out if its ok to go on! Any help would be HIGHLY apretiated!

 

I just talked to an engine builder/machine shop that specializes in the GM LS motors. They said Its right around where it should be and will be perfectly fine. he gave me the formula they use for LSx motors to determine MINIMUM ring end-gap.

.0035 xBoresize for top ring
.0040 xBoresize for 2nd ring

Which gives me

.0035 X 4.00" =.014 MINIMUM end gap for top ring
.0040 X 4.00" =.016 MINIMUM end gap for 2nd ring

So my .022-.025 top rings and .025-.027 2nd rings should work perfectly fine.

 

Your gap sounds good, the spec they gave sounds like a tight stock rebuild. What are your plans with the engine? I gapped mine at: top = .023-.023" Second = .026" But I'm running a turbocharged engine up to 18psi boost.

 

Not planning on ever running boost, just a Good cam/stall and maybe some headers in the future. Mostly a stock rebuild, My build thread is below

https://www.performancetrucks.net/fo...d.php?t=472673