Re: Painting Aluminum Engine?
Aluminum in a salt air environment can oxidize pretty badly, it all depends on the alloy. I'd expect that a thin oil film (or wax, etc.) is all your block parts would need to stay happy, but if you want to paint them, you need to look for an etching primer that is designed for aluminum, and then make sure it is also designed for high temperature because engine paints are not the same as your everyday stuff.
I'm sure there's something out there and a good auto parts store probably stocks it, but if it doesn't say "for aluminum" "for high temperature" and specify a primer...it is going to be flaking into the bilge again.