I got a .030 oversized hyper KB piston now im ready to gap the rings but my Question is does .0065 gap sound right to you? And also they say the top ring needs gapped bigger cause of it running hotter they say to multiply the bore diameter by the apropriate ring end gap factor from the adjoining chart which is .0065. These number seem to small to me can anyone give me some advice.

 

Please some one help me out im sittin here just waitin need to get this engine done and in for the little bit of summer we got left.

 

I always shoot for .028 on the top ring with KB's. You can run anywhere from .024-.028 on the second ring. I haven't had any problems with this in a budget drag race engine. Gap the rings this way every refresh.

-Mindgame

 

when i called KB the tech rep said to gap the lower rings at like 17 to 18 thousands. Now im confused

 

Top ring is usually it's .004 - .0045 per inch of bore so a 4" bore would be .016 - .018. You might want to go .005 with a nitrous street motor. Supercharged or turbo needs .006 per inch of bore.

Second ring is .005 - .0055. Nitrous, supercharged or turbo is .006.

 

Are you saying 0.0065 x 4.030=0.026" gap? If so, that sounds about right. I run a 0.035" gap on my top ring and 0.030" on my second ring but I have a 1" compression height and I'm running 19 psi of boost with an occasional small no2 shot (75hp). I have a little blowby and my oil gets thinned by gas when I'm ******* it so I have to change about every 2k miles. It's not a daily driver so it doesn't bother me--I only take my car out every once in while to race an occassional sports bike.