FML... I'm done for now with sr's and maybe 240's

[racepar1]

Originally Posted by S14DB

AFR doesn't cause detonation. Timing Does.

It doesn't matter that you were running pig rich. If you like that spark off to early that's more fuel that is burning as that cylinder is flying up.

You aren't melting shit, you're blowing shit up.

A lean mixture can cause detonation or "pinging" just the same as timing can. Ever gotten some bad gas? It pings like shit... A lean mixture is almost certainly what happened to the first piston pictured. Timing can't do that. Lean = heat, heat = melted shit. I also seriously doubt that it was timing that caused his latest failure as well. I suspect either an oiling issue or incorrect clearences related to that piston caused it. The way the piston came apart it looks like it seized in the bore and the rod smashed it's way through it.