I have no experience with them, but thinking about using them in a NHRA stocker I am building. Here is an article showing significant gains...
https://www.hotrod.com/articles/ccrp-0301-dyno-performance-piston-ring-test/

I know David Vizard is a big proponent of them, but the debate on SpeedTalk has never been resolved to anyone's satisfaction.

Some folks say they see small power gains.

Others say there's no power benefit, but the engines "stay fresh" longer.

And others, like RAMM, have reported oiling issues; he's NOT the only one to have raised this issue, for anyone who thinks he's an outlier on this subject.

I don't have an R&D budget to prove/disprove their benefits to myself. Since my own limited findings have been inconclusive, I'm using a more traditional ring pack now.

To the person who asked if I liked Napier 2nd rings, I don't have any miles (only dyno time) on the engine to see how the oil consumption is. What I do know is that GM switched from the old 2nd ring design to Napier 2nds as part of their "fix" (or mitigation?) of high oil consumption with certain LS engines.

Like I've said, I've personally used so many sets of these rings SURE YOU HAVE and not had a single issue that I find it hard to believe everyone can't get them to seal. It's a freaking ring. It doesn't know it's gapless. It actually does if it becomes unloaded under high vacuum due to pressure build up between it and the second

I finish all my bores with a 400 finish and hit it with a brush for 8 strokes. Without having the honing book in front of me I can't give you the exact values of the finish but IMO it's not that hard to achieve.

I also know other builders using them and I called one yesterday and he says he's not having issues either. BTW and FWIW I developed my honing procedure way back in 1995 through several phone calls with Earl Garte and several more with Smokey Yunik, since I read an article in Circle Track magazine where Smokey worked with Peterson Machine Tool (IIRC) to develop soft hone brushes. Here we go again with the namedropping huh YellowRose

I've used that finish on everything from tool steel to plain cast iron that were new old stock from 1954 and never had any issues with ring seal.

I also spent many hours on the dyno with the first 3-4 engines that I personally used them in to measure actual blow by under load. The rings every single time showed a massive improvement in blow by reduction.Who cares?

The first engine was a 400 Chevy done by another shop. It was an oil burner. You knew it had no ring seal because you couldn't keep oil in the engine. It would build crankcase pressure and blow oil out wherever it could. When it was sealed up, it would blow the dipstick out.

It was .060 and the owner wanted a new block. I talked him into letting me use gapless top rings to test them and if it didn't work he didn't have to pay for it.

I ran into him earlier this year. It's still going. Doesn't use oil. Runs as good now as the day it came off the dyno.

The moral of the story is if you can't get a ring to seal that's on you. Most rings are pre-seated before they even go into the box. Pre-seated? Never heard of this Cheap rings used to be belt lapped and the better rings were barrel lapped, although there may be a better method now.

There is no excuse for bad ring seal in this day and age. No excuse. To blame the rings is like a machinist blaming his tools for piss poor work.

I never base how I build engines on what OEM's do. I do-pretty hard to compete with billions in R&D

I noticed less blow by at idle, I've never had an issue with oil consumption in any engine I built except one that was washing down the bores because the carb was so rich and that one was fine after putting the long block in an EFI rig.

My last hot rod I built for myself I tried 1/16 rings, low tension top and oil rings with a napier 2nd and it uses zero oil and no blow by holding my hands over the cap and breather holes when hot, just a tiny bit cold and that engine turns over very easy, I can grab the crank snout with my bare hands and turn the whole short block over with no valve train. I did atempt to keep some of the oil drain back from the heads off the crank by draining some of it to the timing chain, I ran a std oil pimp, crank scraper and tighter than normal bearing clearances with highly polished crank journals.

I used to be afraid of low tension skinny rings but all the manufactures are doing it and you hardly see any issues with them burning oil. Mostly true however what is ironic is the last time I spoke with Keith Jones about this very issue he started complaining about how his brand new 2016 GM LS truck burned a quart every 1000 miles and how GM told him it was just the nature of the beast--LOL My 2011 5.7 had 300,000 miles with 1mm rings and didn't burn a drop, just had a flat cam from a roller tht stopped rolling. They use good oil control combined with the thin rings to help efficency and combine that without carbs dumping excess fuel bore wear is almost gone.

J.Rob

I am interested in that also. There IS some recommendations on the TS website. It makes sense because it changes with different hardness of different block/liner.

I have no experience with them, but thinking about using them in a NHRA stocker I am building. Here is an article showing significant gains...
https://www.hotrod.com/articles/ccrp-0301-dyno-performance-piston-ring-test/

I have them in my 451. After 215+ passes in 1.5 years, no oil consumption. So far so good.

Dude, we get it. You can't get rings to seal. Move along. I posted those two names because that's how I learned to do it. I didn't just make the [censored] up. Maybe, just maybe, the issue is with YOU. My junk [censored] doesn't use oil. Why can't you say that?

Yes I read that article to, what to believe?

At this point I seriously doubt you have even held a set of gapless tops in your hand. After honing hundreds if not thousands of cylinders in my 24 years in this trade I have never once had a set of rings NOT seat and consume oil UNTIL I used TotalSeal Gapless Tops which has been exactly three (3) times.

All three engines consume oil at a rate that is well above normal. All three engines crank 195-210 psi and leakdown around 2-4%.BFD So what is a guy to conclude when the data stacks up like this?

A piece of advice Madscientist aka YellowRose--When the data doesn't support the theory you change the theory. Not the other way around.
Then again analyzing data properly is probably a challenge to a "Madscientist" . J.Rob

p.s. Again I ask to anyone--Why aren't these miracle rings in every OEM piston powered ICE on earth?