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