Has anyone experienced this kind of failure on a piston, as seen in the pictures? This is a piston we pulled out today from a 16 645 EMD two stroke engine - non turbo. I can't figure out what caused this or where the pieces went. The engine was run for a considerable amount of time after this mishap (which manifested itself by a large fireball coming out the stack) without complaints - so I am told. The engine has 16,000 hrs on it. The only thing we found suspicious was a broken fuel injector on the opposite side of the engine, but on the same crank throw. Very strange - any ideas.

The funny thing is I had done a scavenge space check, a mere two weeks before the failure, and all the rings were ok at that time.

Looks as if there was a loss of piston cooling oil, resulting in an overheated and cracked crown which allowed oil to enter the cylinder (Note pieces missing from between the ring grooves).
I experienced a similar failure on a Fairbanks Morse piston as the result of a loss of piston cooling caused by a turned bearing.
I would be checking the oil flow to the bottom end and crown asap!!!

From the looks of the top of the crown, I would say all broken parts are dust. all the edges are worn round. Anyway the normal place I find all the bits of an engine are jamed up in a recently fucked turbo.

The top of the crown looks cracked, how are the valve (s) ??