Repainting engine components

For engine parts you'll want to use a high temp engine paint. I doubt regular rustoleum would be up to the task. When I painted the engine in my '79 Ski Nautique I used some engine paint that was available at the local auto parts store.

The block and heads were bare metal from being tanked at the machine shop. For the pieces that had old paint on them I didn't worry about sanding them. I just took a wire brush and knocked off any loose paint and rust and resprayed. It turned out pretty nice.

i used plasti-kote fast dry engine enamel.
it resists heat to 500 degrees. primer dose not ! so stay away from primer when painting the engine .

i used straight rustoleum worked like a champ. if any part of your motor reaches 500 you will have a fire. a steel lawn chair painted black in august in texas will get way hotter than my manifold with a 143 degree thermostat.

Before you paint, clean with a degreaser like castrol purple let dry then use lacquer thinner. And like David F mentioned using primer, metal etching primer works very well, because some brands of paint don't stick well to aluminum.

Kenny:

Obviouly, if using primer, a high temperature primer should be used as the application dictates. High temperature primers are available. You are correct, lacquer thinner is an excellent cleaner and a bit (but not much) safer and less volatile than acetone. MEK also works well.

GeeZZ, If it's aluminum, clean it with 5% phosporic acid, it's an etech,and primer, A boat engine runs @ 160 F. Paint it with 1200 F. black stove paint. Stay away from spray cans, JUST SAY NO!, brush it on.