Lifter galley paint

I've never thought the claims that painting the inside of an engine made a significant difference in drain back, hot oil and gravity do fine. However, keep in mind that engine blocks are sand cast, and there is a fair amount of sand bonded with the as-cast surface of the iron. Painting helps ensure that no stray casting sand comes loose down the road. I've always used Rustoleum red oxide primer, never had any come loose, and probably gained very little by doing so. It's mechanical masturbation. Make me feel good when I do it, but probably won't amount to a hill of beans when all is said and done.