Gapless Rings
 

What are your thoughts on these? Do they have pros and cons? Also I think there is a choice between a gapless top ring or gapless second ring, any benefit there?

Re: Gapless Rings
 

Gapless top ring is a good deal..


The second I would not use as there is not place for the gases to go if its a sealed, Once you get pressure between the first and second ring to top is lifted by the pressure between the 2 rings.

Thats why most pistons have a groove between the first and second groove, Its called pressure seal groove or an accumulator goove. to give a place for pressure to build up so it will not affect the seal of the top ring.

Re: Gapless Rings
 

The gapless top ring is fine. Call Keith Jones at Total Seal and get his recommendation for your specific combination.

I do not use a gapless second ring, as it prevents any gasses that get by the top ring from escaping, that unseats the top ring from the bottom of the top land, causing it to flutter and leak. What little does get by will help the oil ring seal, and won't hurt anything. If the top ring is allowing much of anything to get past, the second ring won't help, even if it is gapless. The function of the second ring is to pull a vacuum on the cylinder, and remove any excess oil that the oil ring doesn't get.

Re: Gapless Rings
 

I agree with all the above. And I've actually gained HP on the dyno, and ET on the track with a gapless top.

Re: Gapless Rings
 

Depending on piston speed, a gapless top ring can be a benefit, or become a detriment.

Re: Gapless Rings
 

I tried the gapless top ring and my results were not good. I went back to the standard .043 top ring.

Re: Gapless Rings
 

It is a strange deal. We always picked up a little with them, but it's hit or miss. Some people absolutely won't run them. I won't run without them. Now, I've tried the gapless second and would never recommend that.

Re: Gapless Rings
 

I've run 3 ring combinations in the same engine,

conventional file fit, 5/64, 5/64, 3/16. Ran good, no oiling issues. (.060 over)

as above except .043 top with gas ported spacer, slowed down about .07, no oiling issues. (.070 over)

Gapless top, picked back up but now oils the plugs. (.080 over)

All were run with napier second, low drag oil ring.

This is a low rpm, under carbed combo so may not be the real world with a high rpm setup.

Jim Mantle V/SA 6632

Re: Gapless Rings
 

Randy, how wide (thick) non-gapless ring were you testing that against? Nobody runs .043" anymore, do they? .023" & .028" is what I hear most about anymore. Do they make gapless rings that thin now?

Re: Gapless Rings
 

No, they don't make them that thin as far as I know. Our last Dart Buick had the real thin package, and I know they were not gapless. Someone else may know different, but I think the super thin rings are gapped. I still run quite a few .043 rings, in fact the only thin ring engine we've done was the Dart Buick. My experience with two ring, .043 top, then low tension oil ring, and .043, ,043, 3 mm, and the 3 ring thin stuff all pulled about the same vac at 20" with a wet sump. There's something there with the thin ring, but quite expensive. My saying is if the super thin rings beat ya, you're real close to kicking their ***. We ran gapless in all the .043 stuff.