Hi 2kx2, as musclerodz says, most paints will hold up on an engine, but preparation is very important. Make sure there's no flaky original paint on there, & absolutely NO oil. Clean the engine & all of the nooks & crannies with a wire brush & then wipe down several times with a degreaser prior to painting. Etch prime first with something like PPG Universel (acid based) & then paint with your chosen paint. For durability I'd spray it with a good quality 2k. I tend to spray engines without the thinners added as it has a higher build & fills in a lot of the small casting indents.... hth
