[Anthony]

Very debatable.

I was talking with a guy who vintage races his CSX3000 cobra, and builds engines, and he said that with the gapless ring in the second position, it doesn't let the high pressure gas to escape from between the 1st and 2nd rings just after the compression stroke, and doesn't allow the rings to "settle" and seal effectively. He doesn't use them. I then emailed this to total seal, about 4 months ago, and the tech emailed me back that it was a complex answer, and to call him for the explanation, which I never did.

Another guy, a highly recommended engine builder told me that they do have lower leak down rates, but that doesn't mean a loss of horsepower. With the engine running, at high rpm's, even with a higher leakdown rate, standard gap rings seal effectively, and he doesn't think it would make a significant difference in horsepower. He thinks the gapless really don't make a difference, and thinks they are a waste of money. Interesting though, he said that he bored out a 427 so, and the next day checked it with a bore gauge and it was .003" out of round. He torked the deck plate back on, and the cylinder went back into correct shape. Point is, I think it's critical to at least hone the block, and preferably bore the engine with a deck plate on to ensure a concentric bore, especially on a thin walled engine block. I think that a concentric bore is more critical for effective ring sealing than whethere or not you're using gap or gapless rings.