There's a product called belzona 1111 (super metal) that would come closer to working than anything I know. We use it in a steam plant to do temporary repairs to steam pipe and it's never failed yet. You have to prep it correctly use a die grinder to clean it up.
Somebody help me out, what am I looking at, a sleeved cylinder with a slot in the sleeve? I see the "ding" at the top. What are you trying to repair?
Is that a groove made from a wrist pin that had moved out of the piston?
Very interesting!
Yes I would go with a sleeve. Applying something in that void, no matter how good it would hold, would be of a different consistency and or hardness and wouldn't wear the same in the repaired area as in the rest of the cylinder.
X2 belzona I used it to repair machines over the years it's not cheep but it works 39 yrs. of machine repair here