700 dragon turbo piston damage?

[bmanke]

I have single ring pistons in a 700 cfi motor. Both pistons have the rings broken right where the ring pin is. Just the ends of the rings broke. Both pistons did the same thing. The rest of the pistons look ok except tops from the ring ends and a groove where the pins are. The ring pins are still in. Doesn't look like detonation. But not sure. I have never seen this type of damage. Any thoughts?

 

[95RXL]

Can you post some pictures? That might help us know what exactly you're talking about.

 

[rydningen]

looks like you have had some detonation from the marks on top of the pistons.
But sounds weird that both rings broke on the same place at the same time

 

[theshadowrider]

It a little hard to tell from the pictures, maybe you could use a better camera or turn up the resolution. Hard to tell but looks like they have been running on the lean side by looking at the wash, or lack of.

 

[bmanke]

The marks on the tops of the pistons are from the ring pieces that broke.

 

[Timbre]

Did you clean the top of the piston when you took it out?

If not, then it looks like this sled was running WAY lean. I have been told the pistons should be dark brown on top clear out to about 3/8" inch from the edge. Yours look completely clean...unless that is just bright lighting on the picture.

Need to see some high resolution close up pictures to be sure.

 

[Kestrel2126]

X2 on the domes looking extremely lean, unless you cleaned them up real good before the pics. Are you running EGT's or an 02 Sensor? Can't really tell by the pics as to whether or not you had detonation. What boost levels were you running, and what kind of Fuel?