Best Engine Paint

[MikeK]

Originally Posted by Terry,NJ

I recall painting the engine interior surfaces with a red paint/coating to prevent seepage through the casting. With oil seeping through the iron it's hard to imagine any paint sticking for very long on the out side of the casting. It's a miracle the paint stick as well as it does.
Terry

Sound iron castings, like those Ford made at the Rouge, do not seep anything through the metal unless it is now cracked or highly corroded. They are pressure tight to a very high degree.

You are confusing porosity with permeability. Two different things. Although interstices between grain boundaries in iron castings may enhance surface retention of lubricants, there is no interconnection of those interstices leading to permeability.

The use of Glyptol (the 'red' stuff) on the inside of an engine is a debatable practice for many reasons.