I was reading an article on Car Craft about horsepower tips and tricks. One trick was to use a high temperature coating on the piston face. This according to the article added 40 hp to BBC they were installed in.
How exactly does this coating improve power?

 

Reflects heat back into the combustion chamber. On a car you plan on building an engine for and having it together for a long time, I wouldnt use it, it has a tendency to come off over time and is hard enough it could damage something or accelerate wear.