It should last as long as you refrain from scratching it.
My process:
-Disassemble and clean intake
-Orbital sander with 320 grit to smooth as much as possible
-wetsand 320 for the rest
-Prime with high quality filling primer. I used four cans on my intake and brackets
-wetsand 320 grit to a smooth feel
-clean with rubbing alcohol and a low-lint paper towel (shop-towels)
-Paint with Plasti-Coat Engine Enamel
Paint tips: Use heavy coats to prevent paint from drying with a texture. Get a thick layer of paint and keep adding coats untill you are happy that the intake looks more like plastic tubes than cast aluminum. The hotter the weather, the less likelyhood of runs. High quality paints tend to run less than generic brands
-Allow paint to dry at least one hour
-Paint several coats of Plasti-Coat Engine Enamel clear. The clear paint adds gloss and a depth to the finish. More coats equals more depth.
Extra cool thing- Sand the texture off of your oil fill cap, prime with plain primer, sand again, paint with a high gloss color, and finish with clear. It looks awesome.
End result=
