Re: Painting the engine
No need for special paint.
Clean the parts to be painted with MEK, acetone, or laquer thinner thoroughly.
After it's dry, use an etching primer for added security, and then paint away with whatever you have.
I have use Rustoleum (o.k.) and Krylon (very good- even on the exhaust...after the first 4") and walmart spray paint (O.K.)