Is your car heating up? Need a new radiator?

Which is better, a brass or an aluminum radiator?

I had a discussion with a friend of mine recently because his car was overheating and he wanted to buy an aluminum radiator. Well, I don’t claim to be an expert on radiators but I know if you have 2 radiators exactly the same size, one brass and one aluminum, and everything is equal the brass radiator will dissipate more heat. The reason the factories use aluminum is that it is lighter and cheaper. When you are engineering a new car from scratch you can make the radiator any size you want.

Lets say you have a ‘40 Ford coupe and you want to have maximum cooling for your engine set up. Because of the way the ‘40 is built it would be very difficult to put a radiator in it with more frontal area. So you say, “I’ll just put a thicker radiator in it.” That’s fine to a point but you soon reach a line of rapidly diminishing returns.

Example, say your radiator is 2×2 feet. That’s 4 square feet of frontal area. If you have a 2-row radiator that totals 8 square feet. If you have a 4-row radiator you now have 16 square feet but when you stack them on top of each other the air flow through the radiator starts diminishing quickly and the radiator looses efficiency. I’d go with brass in that instance and make sure I had a good fan.

On the other hand, say you were building a tri 5 Chevy. It’s fairly easy to mount the radiator in front of the original radiator mount and open the sheet metal to allow more air through. In this setup I would use aluminum. If your car already has an aluminum radiator and it’s not cooling your car good enough, you should paint the radiator black. I know, you paid a lot of money for it and you want people to know you have it but the truth is the black paint will absorb the heat and dissipate into the air as long as it is the right paint. There is a reason the factories paint radiators black. They wouldn’t do it if it didn’t work and they wouldn’t spend one dime if it didn’t.

If the paint is too thick it will act as an insulator and not a dissipater. I’ve found that cheap black rattle can paint works just fine.

As many of you know I have a ‘54 Ford truck with Chevy running gear in it and it worked just fine until I went back to drag racing and started hauling a trailer that weighs around 7000 lbs. I quickly found out I didn’t have enough cooling capacity. Since I had never put a shroud around the fan that’s the first thing I did and that helped some, mainly at idle when the fan clutch was engaged but not when pulling a slight or heavy grade. The thing that solved the problem was to remove the fan clutch and hook it up solid. The bad part of that is you have to listen to the fan all the time which can be annoying. Oh well.

– JACK E. © 2007