This first question refers to having some motorcycle parts refinished.  Specifically engine parts like the cylinder & head.

One option is to have the parts powder coated.
Another option is to have them sprayed with a high-temp paints, which is cured by baking.

Which process is more durable in this application?  Which coating will stand up better to heat cycling and petroleum based chemicals?  
I would say that the high-temp paint (1,100F) is way better than the powder coat.


What about when coating the frame, or parts that are not subjected to temperature?  Which coating is better for a motorcycle frame?

Powder coat the engine. It is much better in chip resistance.
As for the frame. If you have it the way you want (no further welding at a later date). Powder coat the baby!
Powder coat is basically a powdered plastic. its sprayed on then melted to the steel. Verry durable!

Powder coat all the way. Nothing better. The only advantage to the hi-temp black is that you can do it at home more readilly and touch up as needed. Powder is far more durable and expensive.