Engine builders, whats your favorite piston ring?
 

Rebuilding my engines and I have to make a decision on the rings. For blower apps i've used Total Seal in the past but for a 330 to 340HP small block???

It's between the following,

Total seal gapless top ring set

or

Sealed Power Plasma-moly coated, barrel-shaped, ductile iron top rings R9902

Thanks

Andy

total seal would be best but me personally i have a set of seal power file fit plasma moly in my small block with iron second ring..i gaped them at .019 top and .016 on the second ring and i wing my motor to 6200 rpm's

usually the budget dictates what ring to use,if it,s in the budget,go with the gapless top ring,i use them and like them,they seal really good.

Budget yes. Though all my engine builder people say their not sold. I wish I had creditable dyno comparison results. I'm not into wasting money either.

Gapless...N/A or blown...

I have seen a dyno comparison of gapless verses gap style and the gapless did make more power, about 15-20hp. I wish I could remember where I saw the test. My question is how is the endurance of some of the gapless designs verses a good moly ring?

I ran mine for 4 seasons and then blew up one motor (my fault) we checked compression on the other motor and it was 95% of when it was new after 200 hours run time

We use Total Seal rings in almost all of our engines from factory rebuilds all the way to 3000hp twin turbo stuff. We do not use the gap less rings very often I have done some testing with them and had good results. But what it boils down to is making sure the cylinders are as strait as possible and the finish is correct for the material of ring that your using. With that being said I would use a total seal CM set which is a standard classic ductile iron plasma moly top ring and standard second ring with standard tension oil ring. Matt from Totalseal is probably one of the most knowledgeable people in the industry that I've ever meet when it comes to piston rings. Joe Irwin.

Yep, decided not to go gap less. In my case, bore was very straight to start out. Well within the service limits.Still had it honed to make it as straight as possible. Measured right in the middle tolerance wise. Not bad for 580 hrs. Just pulled the Starboard engine yesterday, hopefully looks the same.