Proper primer for painting engine

I sprayed a coat of epoxy primer then sprayed acrylic enamel with the touch up gun that came in my $100 3 pack special. I have about 700 miles on the motor and it looks great. This paint covered very very good. I really believe it is cheaper than spray cans IF you have the primer ect any way for your car.

i put a thin dusting of ppg dp90 on my 400 sbc just because I had it lying around. So long as the block is clean (cleanliness is the key to the paint sticking) then you can just apply paint right over the bare metal.

I clean engine with wax and greese remover, then light coat of ppg dp epoxy sealer, then paint with ppg single stage with hardner, my engines been together 4 yrs now and it still looks like the paint is wet. great durability and if you chip paint from working on it you just get out the touchup brush and it looks like new again, cost more than can paint but I think you get better durability and looks better too.