[Mike C]

I'd go for the Imron. I know several guys who have painted their motors with urethane auto paint with EXCELLENT results. Extremely durable and cleans easily and seems to be pretty darn heat resistan as well. Imron is an antiquated urethane paint at this point, however. There are a lot better paints available now. Dupont makes good paint, but I prefer PPGs. Personal preference more than anything. I have sprayed Imron and Deltron and like the latter MUCH better, but in defense of the Imron, it was a single stage metallic which is a royal PITA.