Another issue could be expansion and contraction rates of a material. If the coating were to chip, it would most likely be at the heads. Since this is where the highest heat expansion would be. Aircraft chambers are made of inconel which is app. 75% nickle headers are made of what, mild steel. F1 does use inconel on there exhaust I do believe.
"Inconel is often encountered in extreme environments. It is common in gas turbine blades, seals, and combustors, as well as turbocharger rotors and seals, electric submersible well pump motor shafts, high temperature fasteners, chemical processing and pressure vessels, heat exchanger tubing, steam generators in nuclear pressurized water reactors, natural gas processing with contaminants such as H2S and CO2, firearm sound suppressor blast baffles,
and Formula One and NASCAR exhaust systems."
http://en.wikipedia.org/wiki/Inconel
Inconel also does not corrode.