Hey guys,

It's true I am no longer a 420A owner (except for one stock piston), however I cam across this that might benefit you all.. might even consider painting intercoolers...

BTW the skyline FMICs *do* come painted black....

Quoted from http://www.Autospeed.com (by *far* the best car magazine EVER):

You want as much heat from the core to be transmitted to the air as possible. Black surfaces dissipate heat much better (and absorb it too - it's a two-way process) than bare aluminium or copper surfaces. In fact, a perfectly black surface will get rid off 14 times as much heat as an unpolished aluminium surface, and 1.5 times as much heat as an oxidised copper surface. With radiators made from these two materials, it makes sense to make sure that the radiator stays as black as possible. A can of matt black spray paint will work wonders.

http://www.autospeed.com/A_0007/page1.html

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Car... Still waiting on it... Now, in Customs Department!!

4WD? Not unless all FOUR wheels put the power down!
HINT: Put your average GSX on a car lift and step on the gas... ;-)

hey dino i remember you telling me your radiator was black..
is that why.. hmm sounds like something i could do

What exactly do you have clearing through customs??? If you have any problems after it clears customs let me know. We had a bitch of a time getting the Soarer cleared when it came through(actually it still isn't totally legal yet) :)

skyline??

Yeap...they're right. The factors that determine how much heat is radiated from a surface are absolute temperature and emissivity. Emissivity varies from 0 to 1 and is strongly dependent on surface finish. Higly polished aluminum has an emissivity, e, of 0.06 @600 Kelvin. Aluminum oxide has an e of 0.69 @600K. Black paint has an e of 0.98 @ 300K (don't know about 600K). So if you put a thin layer of black paint on the IC, that would help. You want to keep it thin, because paint would be an insulator from a conductive standpoint. The heat now has to conduct through the paint to be radiated out at the paint surface. One thing to consider is, "how much of the actual heat removal process depends on radiation?" The major heat removal component may be convection (air moving past IC). Convection has little to do with surface finish.


Corbin

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

but if you could paint the tubing of the IC without the fins.....

There are 2 MAJOR problems with what you are saying:

1) adding a layer of paint to a surface is effectively adding a layer of insulation. painting your IC black is not the same process used on skyline ICs and on Radiators. I'd bet the skyline IC is Anodized black aluminium and radiators are usually oxidized copper. These two processes are a chemical change in the surface of the material, not an adding of insulating paint. By adding black paint to a polished aluminium surface, you don't increase it's emissitivity you lower it by about 4% at high temperatures which means probably 10% or more at normal temps.

2) 600 kelvin is about 620 Ferenheit and 320 Celsius. I KNOW no intercooler will reach such high temperatures and nor is there a radiator that would reach 3 times the boiling point of water either. Hell I get worried if my water temp gets to 120c.

>1) adding a layer of paint to a surface is effectively
>adding a layer of insulation.

I mentioned this in my post.

>painting your IC black is not
>the same process used on skyline ICs and on Radiators. I'd
>bet the skyline IC is Anodized black aluminium

This is certianly true. I'm sure they anodize them. Anodized aluminum has an emissivity of 0.82 @ 300 K. Much better than polished aluminum. But black paint has an emissivity of 0.98 at the same temp. If you could apply the paint in a thin enough layer as to have a negiligible effect on the other modes of heat transfer, then this would be preferable. Is it feasible, I don't know.

>By adding black paint to a
>polished aluminium surface, you don't increase it's
>emissitivity you lower it by about 4% at high temperatures
>which means probably 10% or more at normal temps.

The difference in emissivity for polished aluminum and black paint is 0.04 versus 0.98 at the same 300 K. Not sure where you get the 4%. I may be missing something as it was a couple years ago when I took "heat and mass transfer."

>2) 600 kelvin is about 620 Ferenheit and 320 Celsius. I KNOW
>no intercooler will reach such high temperatures and nor is
>there a radiator that would reach 3 times the boiling point
>of water either. Hell I get worried if my water temp gets to
>120c.

I just pulled those values at 600K because it was most convenient (the tables in my book aren't very extensive). I assumed that the differences would be nearly as striking at lower temps.

Corbin

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