Por-15.
http://www.por15.com/BEngine-Enamels-B?sc=2&category=1
They have directions with their product.
Follow them!
I stripped my engine, wire wheeled (Various size and types needed) Cleaned it with acitone. Masked. Applied their base coating. There is a time you must follow between base and color coat. Sprayed their color top coat. Let dry for a couple of weeks. By the way, it NEVER peeled, bubbled or chipped, especially around the exhaust ports. Great product if done as directed.
I used a weber paint srayer from Home Depot.
Worked. But you can brush it on too, I just wanted a smoother more finished look.