[olddog]

Ceramic coating piston tops and heads and exhaust ports is more common in diesel engines and high end racing engines. As you describe, a ceramic coating will reduce the amount of combustion heat that conducts into the piston and head. In diesels, they can actually measure improved fuel consumption, and higher exhaust gas temperatures. What is amazing is how thin the coating is and what a difference it makes. Racers report that the coating does not last long, but their application is a violent place to live. Diesel engine guys say it lasts much longer for them, but still not the life of the engine.

As for the rocker arm, the only thing I can think of is to reduce friction. If you want to reduce friction, it sounds like you want a roller rocker, but maybe this is a lower cost way to get part way there. I would think that there would be other ways to accomplish the same thing. At some point you will run into the fact that roller rockers are pretty good at a reasonable price, so what ever you do has to be less expensive or much better, to be worth doing.