Warm air intake by painting your intake manifold black

[rh77]

So, would painting the EXHAUST manifold black, make it retain heat more? That's where I'm drawing my intake air from, so a hotter exhaust manifold would yield hotter intake air?

Now painting the intake manifold black is interesting -- I've seen a lot of black high-density plastic intake runners on late-model Ford V-6's (I think they stay cool to the touch because the plastic dissipates heat). So, I think the laws of heat transfer would apply more. Touching anything metal under the hood would be hot because the hot engine parts touch other metallic parts, and the heat is transferred from metal to metal (even the intake is really hot sometimes). The radiant heat around the engine probably wouldn't add much, but tapping into a coolant line and running the line around the intake or throttle body would be a better bet -- it could possibly radiate the heat to the metal parts -- just brainstorming. How easy this would be -- not sure, just make a Y-line from the engine's return line and wrap it around and back, or even a small radiator near the intake, and back to the circulation.

RH77

[bagpipe goatee]

well, according to my ASE book, painting something black make's it give/recieve radiant heat easier. especially flat black.

also, we must remember that radiant heat is light, even if we can't see it.

dark colors absorb radiant heat, but also give off radiant heat quite well.

a black exhaust manifold will increase underhood temps. a white one would act somewhat like a heat-shield. a black intake manifold will be more succeptable to radiant heat, but generally it's on the other side of the engine.

how much of a difference will it make? not much. honestly, i haven't been keeping with this discussion, but i think you'd be wanting for colder air, as on a carb'd car, that would lean out the mixture.

oh, rh77, if i remember right (i didn't look this one up) plastic doesn't dissapate heat well. it's actually a good insulator. that's why pot handles and stuff are plastic.

[bagpipe goatee]

oh, on another note, one of the best ways to measure efficiency of a motor is by measuring the difference between the intake and exhaust temps, the bigger the difference, well, you get the idea. i might be talking out of my ***, i'll go look it up.

[rh77]

Originally Posted by bagpipe goatee

oh, rh77, if i remember right (i didn't look this one up) plastic doesn't dissapate heat well. it's actually a good insulator. that's why pot handles and stuff are plastic.

After posting that, I got to thinking about it -- thanks for the catch. It resists heat via insulation; I'm not certain if it easily gets rid of heat that it does end up absorbing. Also, heat transfer would be less due to density, I'm guessing. I have high-temp flat-black that I painted on my chipping mufflers (on the TL). I might spray some on the exhaust manifold + heat shield in the Integra to see what happens. I have loads of data on intake air temps to compare/contrast.

RH77

[GasSavers_Diemaster]

i talked to my autoshop teacher if that would work. he's tried it all over 30+ years in the garage. it dosent do jack ****. just like matt said.