Justsaws
Addicted to ArboristSite
I think that RD is correct.
It looks similar to some well worn piston skirt and cylinder bombs, perhaps on occasion encouraged by a grinder.
I would have said hung ring but as previously mentioned usually there is more damage where the ring was feeling around for grip before the actual failure.
The images of the breaks in the casting are interesting. There seems to be a wide variety density present. Heat/duration during casting process was not correct for alloy. Could just be the images, but I would think that the modifications may have pushed that particular piston's quality past the safe zone.
It looks similar to some well worn piston skirt and cylinder bombs, perhaps on occasion encouraged by a grinder.
I would have said hung ring but as previously mentioned usually there is more damage where the ring was feeling around for grip before the actual failure.
The images of the breaks in the casting are interesting. There seems to be a wide variety density present. Heat/duration during casting process was not correct for alloy. Could just be the images, but I would think that the modifications may have pushed that particular piston's quality past the safe zone.