Team Fireball

I saw in the image forum a guy that polished his engine, and it is one sick engine. It is absolutely with out a doubt the best looking engine. But what I don't understand is, will the engine not overheat, and how do they polish the engine, I don't understand... the engine's casing has a rough texture on the outside, so how do they get it so smooth and shiny, and wont the engine overheat?????????