What happened to this piston?
 

Not my engine, but I toor down a 2.7CIS engine because of a bad leak down and found this.
I see all pistons have hit the exhaust valve, but cyl1 has taken some more beating.
What happened to that?


http://forums.pelicanparts.com/uploa...1514884591.JPG
http://forums.pelicanparts.com/uploa...1514884591.JPG

Looks like the engine already had a previous failure like a broken valve...
There are some grinding marks on the crown of the piston, I would guess a quick rebuild changing one head and smoothing the dents on the piston...

Looks like it jumped time after a tensioned collapsed, bending valves and breaking rockers.
Not enough damage for a broken valve, maybe just a chip on the face after bending
Bruce

The engine was running so all valves are intact, same with rockers, but similar marks in the cyl1 head.
Would a over rev make the exhaust valves hit before intakes?

But a broken valve and a quick rebuild sounds plausible

Have it been rebuilt previously and had the case align bored?

Where was the leakage when you did the leakdown? Exhaust? Then the valves were recently bent.

It is also possible that something got down the intake like a nut or washer, who knows when. What does that cylinder wall look like?

definitely had some serious hits with the valves... Wouldn't be surprised if a piece of the valve broke off and got chewed on by the piston head.