Brass versus Aluminum Radiators

[jtb]

OK, the big question:

Is there some sort of correlation between the cooling capacity of a brass rad versus aluminum?
For instance, is there a rating in BTU/hr of heat dissipated per square inch or something like that?
I realize there are variables such as number of rows, and fin density, but I am just trying to establish whether a 2 tube aluminum rad will out-cool an OEM 3 or 4 row brass radiator.

I've heard varying theories, not sure which to believe.

Someone out there must be an authority on this?

Thanks,

jtb

[spdkilz02]

wow...that is actually a good question, i just wish i had an answer for you...definately cant wait to see what the "experts" say...

[layed521]

I'm no expert, but I do know my 2 row alluminum rad outcools my old stock rad by at least 20 degrees. Of course its also bigger in all directions, & has an electric fan too.

[GTJIM]

A bit of physics - Copper has a higher rate of heat transfer than ali so like for like a copper radiator (well a brass one ...) with have a higher cooling capacity than an ali one.
However ali radiators are more modern and may have design advances that let them give very good cooling - a lot depends upon relative surface area and how they are made. Many ali radiators are 'cross-flow' radiators rather than top-to-bottom like older copper radiators.

[soybean]

I think the answer lies in the cross-flow as Jim posted. My 3 core doesn't seem to cool as much as I thought it would, which is why I was looking into an aluminum one. Jarrell

[lewdawg]

Aluminum radiators are nice but they are not as durable as the bass ones. If you are looking for dependability as well as cooling capacity you should be able to get a cross flow made or find one in the salvage yard that will fit.

[ddoyle]

From what I have experienced, a cross flow will almost always outcool a downflow. The aluminum, for the same size will be much lighter of course and will not have a problem with the solider corrossion around the tubes, less chance of clogging up. I dont know of any auto mfg today that is not using aluminum. Now if I had to use the copper/brass rad in the opel and wanted the best, a high effiency(smaller tubes closer together) 3 row core, dimpled tubes, louvered fins with about 14 fins per inch should do great. Could get spendy.

Dan

[opelnut10]

Usually copper/brass radiators are found in the downflow versions. The more rows of tubes and the closer togather the fins the better it will cool. Downflow radiators depend on how long the coolant stays in the radiator from the engine. Aluminum radiators,mostly, are cross-flow design with larger tubes and the coolant has to travel farther thru the radiator which also allows it to remain in the radiator longer. The key is to have a coolant that does not heat up as much in the amount of time it is in the engine. There are several products available that will get this done.

[baz]

Originally Posted by opelnut10 Usually copper/brass radiators are found in the downflow versions. The more rows of tubes and the closer togather the fins the better it will cool. Downflow radiators depend on how long the coolant stays in the radiator from the engine. Aluminum radiators,mostly, are cross-flow design with larger tubes and the coolant has to travel farther thru the radiator which also allows it to remain in the radiator longer. The key is to have a coolant that does not heat up as much in the amount of time it is in the engine. There are several products available that will get this done.

there was some chat about 18 monthago about "water wetter" a lot of the south western members use it because it does as you say help get the heal out of the engine and avoids hot spots

http://www.opelgt.com/forums/6b-cool...t=water+wetter
link added

[opelnut10]

"Water Wetter" is a good product and will help in cooling your car. The best after market product that I have found is Evans VPG (evanscooling.com) toll free 888-990-2665. It replaces your coolant and it works. They also carry a full line of cooling system products and make custom radiators. They ain't cheap, their good, but they can solve you overheating problem.

[cherokee]

I went through this a little while ago when I had the rad made for the race car. I was told (sounded good to me) that copper will transfer heat better then al. rad up to a point. There is a point where the copper will get to a temp that the thing will not shed heat very well, it will get hotter and hotter. I don't know if it is true or not but sounded good to me. That al is lighter, but tougher to repair. There has to be a reason other then weight that most new cars have them.

Don't know if any of it is true or not but sounded good to me.

[PROPEL]

Originally Posted by cherokee There has to be a reason other then weight that most new cars have them.

Yeah, aluminum is less expensive.

[cherokee]

With the prices going for scrap copper I would have thaught it would have been the other way around.

We had guys come in and pull HUNDRED of yards of cable when I was at coke a while back. That was a great deal of labor for not very much return. Not a lot of copper in networking and old phone cable. And they told me the price of copper is through the roof...enough to have 4 guys out there pulling out cable.

[jtb]

Well,

Lots of good info, but still no hard numbers!
So, just to stir things up: an aluminum crossflow rad should be able to out-cool a downflow brass rad, even if the brass rad has a greater surface area. Hmm... up to what point? At some point, as the surface area increases, it must match cooling ability of the aluminum rad. Perhaps there is no easy answer to this, as there are so many variables.

(I'm actually interested in this for my truck, I already have a crossflow aluminum rad in the opel).

Thanks,

jtb