This is a cooling tip I was told and researched and seemed very plausible.

That a radiator painted black will cool 15% to 20% better than an unpolished aluminum/copper radiator.

 

i have "heard" this but i have never seen proof. on the surface it would seem like the paint would insulate the radiator causing less heat transfer. but like i said i have never seen proof.

 

Well I did my own test and I got temps down 10 degrees without anything else done. I mean I know thats not the claimed 15 to 20% but its still alot know what I mean?

 

Not to sound stupid or anything, but you painted and tested your radiators capacity in just 15 minutes???

Or did I just miss something????

 

No I had done it, and just wanted to pass along the tip.

 

Strange as it sounds, I believe you are correct, and I think that flat black is better than gloss. while I was growing up, my dad had an airplane, air cooled 6 cyl engine. I'm not sure where he found the tip, I think some guy named ricardo who wrote a book about internal combustion engines. Anyway, he repainted the cylinder cooling fins flat black and the cylinder head temps dropped 15- 20 degrees f

 

Does anyone else have any results on this?
My dad who has many classic cars has MANY copper radiators all blacked out.

 

Mine is copper single row and black, and I run cool ALL the time - even here in Tucson with summer temps averaging a high of 100F for months at a time.

Copper transfers heat better than Aluminum, always will.

I think the black paint may contribute a little, but find it difficult to believe claims of 15 to 20% temperature drop.

A word of caution here - there is special spray paint for radiators (regular spray paint is too thick and will flake off over time) and it is available here:

http://www.eastwood.com/itemdy00.asp...40+Z&Dep_Key1=

Stay cool.

 

This is true I forgot to mention that. There is a special spray, yet I beleive the less gloss the better. This isnt the only one.

 

I think its more of a cosmetic issue than anything. Alot of guys who restore old cars are fanatic about being "correct".

 

As RonKMiller said, generally speaking,...the copper radiators will run cooler (give the same size).

Copper Radiator
Pro - better cooling (assuming size is equal)
Con - heavier than aluminum (assuming size is equal)
Con - Corrosion (unless the interior is coated). Ever see the copper piping in your house after a few years? I would say that the higher end radiators are coated, whereas some of the cheap copper ones are not.

Aluminum Radiator
Pro - lighter than copper (assuming size is equal)
Con - Copper cools better (assuming size is equal)
Con - aluminum radiators need to be BIGGER to compensate for Copper's better cooling abilities.

Ever since the rise of aluminum radiators in the marketplace,...the Copper manufacturing industry has been pushing to have OEMs use copper again. (Look up the term "CuproBraze").

Here...read this.
http://www.eng-tips.com/gviewthread..../108/qid/61247

Griffin Radiator FAQ
http://griffinrad.com/faq.php

 

Well Ive known that copper cools better, but has anyone else tried the black radiator thing?? Just wondering? Im going to ask my friend to try it out on his WRX since he sees the track alot.

 

im building up my car now...my radiator should be here within a week and im gonna try this....this should be neat.

the radiator will be stock

 

Put a light coat, not to thick dont want to cause build up of insulation.

 

what about having a flat black aluminum radiator? would the same apply for aluminum radiators or just the copper ones?

 

It applys to both. You would probably see more difference on an aluminum than a copper though since copper arealy gets temps pretty low.

 

Hmm how about ICs?

 

I have no idea, if anyone wants to test that out feel free. I was thinking how about the oil coolers as well, maybe thats why they come black?

 

Same deal for IC's - it's just an air-air radiator. If it works on the water rad, it'll work on the IC.

The key is to have the increase radiation efficiency from the flat black color be greater than the insulation qualities of the paint. I would think a flat black anodize would be great.

 

I wonder if doing one of those black zinc/annodized finishes would be even better than a coat of paint?

 

Does anyone have a technical explination for this. I just dont see how it would cool and better have coat of black on it. What if it was a coat a red or blue how would that change it. i know that black attracts light better then lighter colors but i dont see why it would disapate heat any better.

 

This makes ZERO sense.

 

 

It has something to do with the fins absoribing more heat (maybe more area) and then the wind takes it away. I have no idea, yet it seems to work. I tried to have the conditions as constant as possible.

 

i'll ask my father tonight; he is a mechanical engineering. Black conducts better than other other colors. this makes sense i just can't remember the explanation right off top. something to do with radiative/conductive heat.