Ring gap requirements

[440magcars]

The top of 3 of my pistons broke off above the top ring. Engine builder gaped the rings at .024 top ring and .015 2nd ring. seems a little tight for a forced Induction engine. Anyone know for sure what the ring gaps are supposed to be? Engine is a 508 stroker F2 Procharger.

 

[toolmanmike]

The top of 3 of my pistons broke off above the top ring. Engine builder gaped the rings at .024 top ring and .015 2nd ring. seems a little tight for a forced Induction engine. Anyone know for sure what the ring gaps are supposed to be? Engine is a 508 stroker F2 Procharger.

What's the bore size?

 

[440magcars]

Bore is 4.36

 

[70wayfarer]

Bore is 4.36

4.36"x.006"=.02616" top ring and put second ring at .028" even a little more on both won't hurt. if block hard filled x .00675"

my bore is 4.040" and gapped rings at .027" top and .029" second ring. my block is 2/3 filled

 

[RustyRatRod]

Call your piston manufacturer if you want a real answer.

 

[440magcars]

Ok thanks guys!

 

[mcat]

.028 top .030 2nd on my boosted 3.917 bore
you were definitely too tight

 

[70Duster440]

70wayfarer outlined the general rule of thumb. I used a factor of .0065. On a 4.35" bore I was at .028" and .030" respectively. I'm curious to know what your static compression ratio was and what kind of boost level.

 

[440magcars]

compression is 9.2 and around 10lbs boost at half throttle.