Referring to Bob Hoover's long article here to keep it short.
Bob, do you have any tech references that show exactly how these thermal dispersion coatings work for _exterior_ surfaces? I know how the internal head and piston crown barriers work, but exterior surface coatings are, IMHO, successful largely because they entail a thorough cleaning of the surface; then the thin coating helps keep the surface clean because it more easily sheds sticky grime. For that application, I'll just stick to my habit of keeping the engine clean.