It's been a while because I've been busy with a new job and this truck is on the bottom of my list of things to do but I finally got the piston out tonight.

There's a section of the piston between the two upper rings that appears to have broken and then just burnt away and the second ring is broken. Anyone seen this type of burnt pattern before? What might have caused this?

Attachment 2186 Attachment 2187

Thanks

A lot can depend on what this vehicle was used for , how it was driven, quality of fuel, and if all the safeguards built into it were working and not ignored.
Detonation will remove the second and third ring lands of the piston(s) and I think it would be a wise decision to remove and inspect the remaining pistons. Somebody knew what they did here and decided to get rid of the truck rather than fix it.