Originally Posted by roykuz
Will painting an engine contribute to overheating? I have a ford 4.6 alum.block and would like to paint it. I was told that I would be better off just cleaning it and hi-temp clear coat. Any thoughts out there?
Thanks in advance
Bare aluminum is quite reactive to the elements, a good coat of paint protects it from water, air, battery acid, coolant spills, etc. that can cause pitting and corrosion of the material.
However, since aluminum forms an oxidation layer rapidly on exposure to air, getting paint to stick can be a problem. Often this is overcome by using a self etching primer.
If the engine is air cooled then a layer of paint can directly affect the operating temperature of the parts involved, but so does layers of corrosion and grime. If liquid cooled, there is plenty of extra cooling system capacity to handle any loss of heat rejection on the outside of the cooling jackets. So this is a non issue in the real world.