2IROC

This is a question on ring gap.
For those of you that have Keith black pistons in your car.....did you gap the rings ( top compression ring)?

RedIrocZ-28

When I installed my pistons, yes I gapped the top ring. I can't remember what I gapped it to but it was what the manufacturer recommended.

aklim

Now I am curious. Aren't you supposed to gap them whatever piston you use?

ZZ430RS

YES you should always gap first and second rings to what the ring manufacture recommends,it also depends on if you run NOS or blowers (they need more gap) unless you go the easy route and buy pre-gapped rings, but those always have more gap than you need and cost several horsepower.

aklim

Bad gapping cost power and IMO will suck at oil control too.

2IROC

Welp, I bought these from summit. They recommended speed pro rings...being most likely to be pregapped. Considering they know that kieth black pistons have to be gapped or the crown of the will break due to heat tranfer.

Also I dont see how you can lose several hp just off ring gap.

ZZ430RS

If you gap to the proper specs then when the engine gets warm the rings should close up to almost a zero gap, that lets less pressure past the rings and keeps more of it in the cylinder where it helps HP, pregapped rings ALWAYS have more gap than they need so they will work in any bore size that piston is likely to be put into, therefore when the engine warms up there is more ring gap, therefore more blow-by and lost cylinder pressure which means less HP. Car Craft tested the same engine awhile back with pregapped rings and file fit rings and the file fit rings made 7 more HP and 10 more ft. lb. of torque. Gapless rings made another 10 hp.

2IROC

so what your sayin is that you lose compression.

Ive got the pregapped rings by speed pro. Gap setting is .15-.25. I hope they work.

TunedPort 335

I have Keith Black pistons, and Moly Rings. The rings were pregapped.

I checked the ring gaps just to be sure, and they were spot on

Hope this helps..

2IROC

Thats what I needed to know. Thanks alot!
Dave