There was a post recently about black paint dissipating heat quicker, something about the radiator being black for just that reason. Anyway, using that theory, would painting the intake manifold black do the intake air any good? I mean the manifold isn't in direct sunlight or anything but the thing gets motha fuggin' hot, so would painting it black make any difference whatsoever. Any improvement in intake temp would be worth it to me since I don't give a rats @$$ about the way it looks under my hood.

Please help with this, I need some educated answers here people :P

Coo'
alex_ries@hotmail.com

hit up corbin he painted his black but im not sure if that was his reason behind it

I don't think painting it black would make it that much of a difference, but I could be wrong

I believe the air inside the intake would have to be more than the air outside for it to work. Because of that a more reflective surface would be good on the intake.

Your best bet would be to use a ceramic based paint to keep the engine bay heat from tranfgering fully to the metal of the manifold below the paint. Ceramic coating, and ceramic paints have good insulation properties so you would keep some heat out with paint, but not as much a a true ceramic coating.

Una salus victus.
It's not about being invincible, it's about being ready; for anything.



Michael J. Kulaga
e-mail: Michael_97RS@2gntDSM.zzn.com aol IM: MJKulga
http://highlander.dsmpower.com/

Injen CAI, 55mm TB, Hooker 4-1 Stepped Header, GS-T Muffler, AFX UDP, S-AFC, 8.5mm Magnecor Wires, Crane Fireball HI-6DI2, SS Clutch Line, NRG Susp. Motor Mount Ins., FU/RU/RL STBs, TSW Blade 17x7.5, Bridgestone Potenza RE730 215/45ZR-17. Front KVR Cross-Drilled Rotors & Carbon Fiber Pads

To Be Installed: Ported/Polished Intake Manifold 1/2, Rear disc brake conversion kit w/, Rear KVR Cross Drilled Rotors & Carbon Fiber Kevlar Pads, SS Brake Lines

I'm pretty sure that black dissipates heat better because of the visible light aspect, because it is in the sun. I don't think that if you put a black pipe or a blue pipe next to a heat source it would make a difference, but next to sunlight and it would.

But what i'm thinking is if you wear a black shirt outside, it gets really hot. Or if you have black hair, wouldn't you want to paint it something that stays cool, so that it absorbs more heat from the air inside than the sun outside? If the sun heats the black faster, then heat can be taken from the air inside....

Just my thoughts

My upper manifold is painted black, but thats just cause I think it looks cool.

I'm not going to commit to whether painting your manifold will provide any real benifit. I have taken a "heat and mass transfer" class, but I am no expert on this. However, I will go over some basic aspects of heat transfer. If anyone knows more about this than me, please post more details.

Heat tranfer occurs through conduction, convection, and radiation

Conduction: Touch a hot piece of metal and the heat is conducted to your fingers. The associated material property is the "thermal conductivity, k".

Convections: Heat transfer from a radiator to the air moving past it is convection. The assosiated material property is the "convective heat transfer coefficient, h".

Radiation: Heat transfered by electromagnetic waves is radiation. The heat from the sun travels though the vacuum of space to us by this method. The associated material property is "emissivity, e".

This paint discussion has to do with all three forms, but primarily radiation. Changing the emissivity of a surface will have a direct affect on the heat flux. Flux being the heat transfer rate per unit area (like Watts/meter squared). So if you can increase the emissivity and all other factors remain equal, you will increase the heat flux from the surface.

e for various things at 300K (about 80F)
Polished Aluminum: 0.03
Anodized Aluminum: 0.84
Black paint (Parsons): 0.98-->I don't know what Parsons means
White acrylic paint: 0.90

The problem comes with how you change the emissivity of the surface. If you paint it, then you now have to transfer the heat through the paint (conduction and radiation). Then it can be conducted, convected, and radiated away from the paint. You could picture how this could actually "insulate" the surface with paint. Anodizing may be a better choice. I think the anodized layer is extremely thin and durable. It probably has better thermal conductivity than paint too (but don't quote me). But there are alot of details that play a role in what the net result is from all this. I don't have the time or energy to delve into this anymore.

Corbin

'95 ESI-T
HRC+FMIC+ETC...

Yo Corbin, I understand what you're saying. I also think that the paint would actually create a shell around the manifold that would make it harder for the heat to dissipate. Aiight.

Coo'
alex_ries@hotmail.com

wouldn't the intake mani pick up lots of heat from being connected to the block? if so then insulating it would be keepint the heat in

Yeah...it picks up ALOT of heat from the head to manifold connection. There is alot of surface area in contact and both materials have high thermal conductivity. That stock gasket won't insulate much. Thats why the intake manifold spacer/insulator sounds like such a good idea.


Corbin

'95 ESI-T
HRC+FMIC+ETC...

depends if thiers anything in the paint ie ceramic qualities that will allow it to be shielded from engine heat

OK, so let me get this straight. For best engine performance and coolness you should: Lightly Powdercoat the radiator black, Powder coat the engine black along with the lower mani(when using spacer). Than get a powdercoated intake that is silver. Wouldnt this work best? Ohh, and ceramic coat the exhaust so it flows faster and keeps engine cooler.