460 blowbye

[Newold1]

If the new pistons were not the same brand and # and the rings not a different brand or # the problem might be being repeated, but I doubt that. I am leaning towards two possibilities for the ring problems, one end gaps to tight for that bore size and two those bores might look and measure straight when not under load but I suspect those cylinders might be two thin. Its possible the ring end gaps were just open enough that the rings gaps closed just slightly and the rings lost tension to the bores. What was the readings when the bores were sonic tested? Can you post pics. of the faces of the old rings, just the top two rings?

[kbr577]

Just a quick update, bores light honed and washed, new pistons, and everything seems fine now, no more blowbye.
Thanks for all the input!!!

[mag2555]

Good to hear!
Why did the Pistons get replaced, where they part of the problem?

[kbr577]

Think the ring groves were screwed up.