I have an olds 403 street/strip motor with about 500hp. 4.375 bore and im using the kb hyper pistons. Ive been told by numerous people running 403's to use a large top ring gap such as .035-.040. mine are set at .035. The second ring gap i got a little to crazy with the file and they are .030 and one of them is even .040. Can i run my engine this way or will i experience problems?

 

I just did a BBC with the same setup. Bore was 4.165 with .030-.032 top ring gap, no issues.

Your second ring may be a little big but if it bothers you that much just buy a set of second rings or just get one to replace the one you have at .040. A full set of rings is what $80.00-$100.00, your call.

Bottom line you might be giving up a few hp but it really won't hurt anything. Remember the second ring is just as responsible for oil control as it is for sealing compression.

 

so what will running the bigger cap cause and where can i find cheaper rings? All the sets i find are no less than $150. I am going to try hastings though and see if i can get a set of second rings.

 

1st thing is compression loss, although minimal. 2nd would be oil control on the second ring, but I'm not sure it would really be an issue.

I'll check my sources for rings too and let you know. I'm guessing 5/64 rings?

 

no 1/16

 

Check the KB web site, they have great support info including a good artical on ring gaps and the effects