Tearing down an old seized m129 engine, I got it freed up, but noticed on one of the walls corrosion? or pitting. Could this be porosity of the casting where water is entering? Low miles but many years on a second bore 83mm.
You can see a pit just below the piston ridge.
Has anyone seen this before? Ideas?
How do I test?
Can it be brazed? or epoxied from inside the cooling jacket? looks like access is possible on number 4