Old School 340 Build

yellow rose said
Unless I'm running gas ports, I use gapless tops.

I've seen them reduce blowby by 8-10 CFM. That was on a 400 Chevy and they suck at ring seal. They are in my engine now.

Woooooops....wasn't supposed to let M.O. Know I had something.

Haha maybe I'll give them a shot. It would be interesting to see the difference.

67autocross said
I will ask Mike a few details next time we talk, I know he mentioned something about degree he installed the cam at. He was also very addement about the gapless rings and how he wanted the block honed, claimed it would be good for 20hp.
He said I left 25hp on table by keeping the old cam but for the money I have into it it runs good.....plus he gapped the rings for a small shot of NOS

I'd be interested what icl he came up with when degreeing the cam. I'm not at all surprised he thought a hone and rings would be good for 20 horse. Hughes did an excellent test of that. They didn't like the ring seat they got, pulled it apart re did the hone and put new rings on, they saw about that much. RAMM on here had the same results on that 416 he worked on. Had oil problems and he did a hone and re-ring and some other minor work. Cylinder pressure went from 180-195. Horse went 488 - almost 530 if I recall.

Just more proof that the devil is in the details.