My LT1 has about 140,000 miles, while tearing it down this weekend for a rebuild and build-up, one of the pistons had a little piece on the outside edge missing(just the top layer above the first ring), and the rings were gone. What could of caused this?
And how was my car still running low 14's and capable of high 13's? The cam had some markings on 2 or 3 of the lobes as well.
I'm surprised it survived.

 

Any ideas?

 

detonation maybe is the most common cause of cracked piston's.. but on a high mileage motor.. who know's..

 

What exactly is detonation and what causes it?

 

running lean, too much timing not enough octane in the tank.. are a few reason's. .. its a really bad sound you'd know it.. ify ou heard it pop..

 

It must of happened to one of the previous owners

 

As I understand it the ring lands are the weak points on these hyper. pistons. Predetonation is a frequent cause.