924Board.org

[Joes924]

I thought painting the block was a heat inducer.. hate to see a guy that has more than one color under there..
[ This Message was edited by: Joes924 on 2002-03-12 16:51 ]

[ This Message was edited by: Joes924 on 2002-03-12 17:10 ]

[Cbass]

Use good quality paint for engine painting. Ceramic header coating is excellent. It only raises the engine temperature if you have a really bad cooling system, and makes for a much cooler engine bay.

[JvGinPDX]

Engine color and heat transfer. If radiators are painted black to help get rid of heat, would it make sense to paint the engine the same color? It would not be pretty, but would it work better. I am not into showing off my engine anyway, I do not care if it is aluminum color, black, or pink with purple polka dots. Bottom line, to get rid of heat, what color works best?

[Smoothie]

Good point... Infrared red should work best.

Just kidding....(I think.)

[Pat]

The coatings and paints don't actually reduce the engines temperature, they simply reduce the engine bays ambient temperature, and keep bare metal from corroding or chemically reacting to anything that ends up in the engine bay. To put it simply these coatings keep the heat where it originates (well close to anyways) instead of heating the air and other objects in the engine bay. The most effective heatsink colour though is black or very dark, reflective you want white or a shiny metallic (silver, chrome, etc.).

[D Hook]

Pink with purple polka dots....Hmmmmmmmm....

[Joes924]

I thought I remembered hearing that it acts as a blanket and kept heat on the block..I was wrong see I was wrong.

[Cbass]

It does. Lets say an engine generates 10,000 BTUs of heat. The radiator is designed to reduces this heat by 8000 BTUs to keep a static temperature in the engine of 200 degrees C. The engine radiates the other 2000 BTUs from the block and headers, heating the engine bay to about 75 degrees C.

If you can reduce the heat radiating from the engine through the block and headers to 500 BTUs through header wrap/coating and insulating or reflective paint, the engine bay will drop to about 30 degrees C, and if your induction is in the engine bay, it will make a little more power. Not enough to notice. However, hoses and stuff will last longer, and the hood won't get as hot.

The radiator takes up the slack, and now cools 9500 BTUs, while the engine temperature stays the same.

If you want a cooler engine, get a cooler thermostat. If you want a cooler engine bay, get good header wrap or get your headers coated with Jet coat or another ceramic based coating.

The newest theory I've been exposed to is that when you lose heat from your exhaust, you lose energy and power, hence wrap and coatings. However, keep in mind the rest of the exhaust system is going to lose quite a bit of heat. This theory is quite new I think, and as such, probably hasn't simply been debunked yet.

The numbers I posted are just for example, and have no bearing whatsoever on real life. Besides, even if they were accurate, they would be very subject to ambient temperature. Hope I've been helpful.

[ This Message was edited by: Cbass on 2002-03-13 15:08 ]

[Paul T.]

I say paint it! Unless you live in the freakin' Sahara Desert, the heat difference just doesn't make that much of any difference. I painted mine with two good coats of aluminum high temp engine paint, and it looks great! Piss on the details of something like this, a rusty looking block SUCKS! Besides, after all of the work you put into one, the engine should look nice.

[JvGinPDX]

I agree that painting makes an engine look better. Our engines are rather ugly, strange looking beasts, at least in my opinion. ( I was kiding about the polkadots of course. My question is what color of engine paint (if any) would reduce temperature in the engine bay?

[JvGinPDX]

I agree that painting makes an engine look better. Our engines are rather ugly, strange looking beasts, at least in my opinion. ( I was kiding about the polkadots of course. My question is what color of engine paint (if any) would reduce temperature in the engine bay?

[JvGinPDX]

I agree that painting makes an engine look better. Our engines are rather ugly, strange looking beasts, at least in my opinion. ( I was kiding about the polkadots of course. My question is what color of engine paint (if any) would reduce temperature in the engine bay?

[Alex Roy]

black is good for transfer of heat----it would be good to make your engine try to equalize the temperature with the ambient air.

silver (or white) is good for reflecting heat (that is the reason allot of house insulation has a foil layer, it is good at keeping the heat on one side from the cool on the other side)----this would be good to keep your engine it's own temperature and the ambient air it's own temperature.


in other words, it all depends on what you want to do.

_________________
Alex Roy
White 924 N/A, BAE turbo kit, Gemballa body kit, Haltech E6 engine management. A project in progress.

[ This Message was edited by: Alex Roy on 2002-03-13 15:47 ]

[924 turbo]

Check out this short article on paint colors for engines.

http://www.avweb.com/articles/engpaint.html

[JvGinPDX]

Thanks Jon, that does answer all my questions. We just go for pretty, if it matters to us. Painted engines are nicer to look at.