ludesleep

Basically there are three different types of thermal coatings.

1.)Thermal barrier coatings-These coatings tend to help manage the effects of engine heat by insulating and/or reflecting heat at various component locations(ceramic coatings)
2.)Low-friction coatings
3.)Heat emitter coatings-These coatings have a high heat transfer. Used to shed or radiate heat away "emminsivity". This would be used on valve springs, air cooled cylinder heads, intake manifold(inside and out), oil coolers, radiators, intercoolers,O.D of cylinder sleeves, exterior of oil pumps, valve covers, and fuel rails.

When using thermal barrier (ceramic) coatings such as piston domes. This will cause less piston growth allowing the builder too run tighter piston-to-wall clearance. Same for combustion chambers and faces of valves to prevent heat travel up the valve stems.

Coating the exhaust ports and outside of the exhaust manifold also creates a scavenging effect contributing to a more efficient exhaust "pull". Allowing the heat to stay in it area, rather than sink and do nothing but waste energy.
Applying ceramic must be done properly. Surface must be clean, dry and even a slight finger print could cause flake or dislodging. Most builders use a process of "Ion bonding" which is sometimes applied in three different layers. This causes the first layer to actually become apart of the parent metal. The surfaces are prepared with a microscopic profile to accept the coatings, and the coatings are "metallurgic-ally" bonded.

There is also a "Black body radiation theory" generally saying that black is the best color to transfer heat. Once you go black you never go back

Coating has a positive effect on combustion and generally will move an engine away from detonation. Allowing a leaner mix, more compression or both. Also the timing can be retarded a little, as maximum burn will be reached sooner during the stroke so not as much advance is needed before TDC. This helps mid range without sacrificing low end power. Peak power will improve