Hot Rods Aluminum VS Copper/brass Radiators

I'm sure this has been brought up before. Cost not being a factor, which is a better radiator? I see a ton of aluminum radiators in use,I know they're cheaper than Copper /brass, are they better?

 

I think who makes it plays a factor.
Also some talk in years and some in miles.
I’ve had DD’s with over 200k on the factory aluminum radiator. 20 + years old.

 

This usually starts a BIG argument....Many will say that aluminum transfers heat better than copper/ brass. I would have to disagree, just my personal opinion. There are quality radiators from both materials and sometimes availability and cost are the determining factors. Getting older copper/ brass ones re-cored can also be a costly adventure. There aren't too many radiator shops around anymore since the OEM ones (aluminum) have largely become "throwaways". The car companies went to aluminum for cost and weight savings, not necessarily for long term reliability. That said, your results may vary.

 

If you can find the video of Alan Johnson building a radiator since he took over Walker, check it out. There's a lot more to building a quality radiator than one might think.

 

The vast majority af aluminium radiators in the custom aftermarket are made in China. Not because it's a better material but because cheap welded fabrications are easier for them to make. I don't see them as repairable as traditional brass..... also add on the corrosion factor.

Your choice.

 

Aluminium is about 60% as good a thermal conductor as copper — but brass is only about half as good as that.

Aluminium is also light, abundant both as ore and scrap, and readily recyclable.

The main problem with late OEM aluminium radiators is the plastic tanks. Aluminium tanks can be made to fit OEM radiator cores: whether there is any sense in doing that is another question.

Making heat exchangers of any kind is a fairly widespread light industry. There are probably 10-20 companies doing that in my town. The plant involved isn't prohibitively expensive. In theory custom-made aluminium radiators should be fairly affordable.

 

Somebody mentioned corrosion. I think it is more of a factor with aluminum than copper/brass (because of their galvanic qualities).

Someone else mentioned the aluminum radiator lasting for 20 years on their DD. I think that has a lot to do with the protection afforded by proprietary coolant mixtures. When my DD (a Kia) hit 100K, I was shocked to find that it was strongly recommended that I use their coolant at over $50 per gallon for pre-mix.. If the car had still been under warranty, it would have been voided had I not used it. This is why there are several types of antifreeze on the market these days.

Because of this, I use a magnesium sacrificial anode in my flatheads running aluminum heads. You would be shocked at how much one will deteriorate over only a couple of years. If I were to run an aluminum radiator, you can bet I'd run a magnesium anode. (I'm not enough of a chemist to figure out the proper antifreeze formulation.)

 

I just use the premix from AutoZone.
They carry a Dextron, stuff (that’s supposed to be) compatible with many auto manufacturers.
But I’d tend to agree about the types of coolant available these days.
I recall many, many radiators in the non-aluminum days, showing the green corrosion that formed from leaks/seepage in the tubes or from the tanks.

That was when green antifreeze, like prestone was about the best (to my knowledge) around.

 

You ain't kidding. When I had my 47 Olds original radiator re-cored last year it cost me $950!

 

^^^^^ Ugh, times have changed!!!

 

That was the cash price, he had quoted me $1150

 

...WOW!!

 

Yeah, that put a nasty dent in my car fund

 

....I had the one in my Forty re-cored a few yrs. ago. It's a '55 Chevy radiator. Cost me $800 which I thought was high. Guess things have even gotten worse.

 

$250 five years ago to recore a '46 Mere heater.

 

I researched this question for many years
My 57 Tbird tended to overheat so I was considering a 4 row copper brass radiator for around $600 at the time.
As said copper is a better conductor of heat transfer but what I found out with all the brass and solder to construct it degrades the effective heat transfer.

I found an aluminum 2 row radiator for $180 that was made to resemble the original Tbird radiator
It was explained that aluminum is stronger than the copper and can be made with larger tubes and vanes to allow more flow of coolent and air past the tubes.

that being said I have a 4 row Walker radiator in my flathead roadster and sometimes it runs too cool in ambient temps below 70f
It’s all about the quality and then the proper care and maintenance.

 

And if your aluminum radiator springs a leak there really is no "fixing" them other than maybe some off the shelf "tonic". Radiator shops won't touch them.

 

From my experience and observations, FWIW.
My DD, 1992 Buick Roadmaster aluminum , from the factory, began leaking after 80,000 miles and 28 years. No, the local shop could/ would not repair. SO a replacement, for $150 ,or thereabouts, shipped to my door. Looks JUST LIKE THE ORIGINAL.

My 1950 had a new copper core installed when I redid the car in 2008/2010. About $400, if I remember. NEVER had anything inside except distilled water and anti freeze. Plugged up after ten years and 20000 miles. $150 to rod out.

SO, to the OP and others, your results may vary. These are mine.

Ben

 

I've had multiple's of both. 3 Walker's, 3-4 alum. Walker's IMO always overpriced, of course they say "repair" easy, only buy once, etc.etc. To me that wound up as total BS. First Walker I bought wouldn't cool, called Walker himself, said I needed a "heavy duty" one (plus about $500.more) to cool a .30 over stock chevy! Instead, bought the cheapest alum. on ebay, about $140. or so, and it lasted 6+ years until I sold the car--car ran at 175 w/ ac. Walker had a sweet deal going for a long time.

 

First..."better" at what ?

1 - Aluminum is better with overall weight.
2 - Copper is better at heat transfer. It's an Engineering thing. (Just look it up!!)
3 - Copper is better with the "look" of a copper radiator.
4 - Aluminum is better as polished aluminum top tank better.

So...there you have it...it's two to two, even score ! Pick which you like best.

Mike

 

they can be welded

 

It's too bad 50s Chrysler radiators aren't affordably available. This was a mid 50s one, just boiled out and 2 bungs soldered in, that I used in the modified in the mid 70's. It was a honeycomb core, and was so good at cooling, I had to block off over half of the core face to restrict airflow thru the core, and never needed a fan. So, okay, it was running on methanol, which helped to cool the engine, but even so we had a hard time getting temperature in the engine, even on the hottest nights. I can only imagine how expensive it would be today. With the radiator shop bill, I only had about $30 in it. It came out of a salvage yard for scrap cost, about $5 then.

 

My Afco aluminum is going on ten years old, its been weeping at the lower right corner for three or four years now. Tubes are epoxied in so no real fix for it. I cleaned the area with a soda blaster then coated it in 3M panel adhesive, I can still smell the hot coolant but don't see anything. I will keep running it as long as I can then go with another brand of aluminum.

 

This subject has been debated for several years, and the internet is full of opinions. Pros and Cons of each. I think Mike summed it up best, it is a toss-up.

 

Regarding the heat transfer ability of the 2 metals- yes copper transfers heat better. But the aluminum is stronger, which means it can be formed into a more efficient radiator shape. You dont see copper tubes that are 1" or bigger oval cross section like an aluminum one.

The ulitmate would be a copper one shaped like an aluminum one. Maybe there is a copper alloy that could do it, but if there is, then it's too expensive. Otherwise, it would have already been done.

-rick

 

Bringing back this thread, as I have had a brainstorm, or nightmare, you guys decide.

Copper is better for heat transfer, aluminum is better for larger cross sections. This would be expensive, however it might be worth it for a better radiator. Copper clad aluminum tubes. The way I see it would be to clad both sides of a strip of aluminum, then form the tube. This would give copper on both the inside and outside of the tube, and minimize the formation of aluminum oxides that insulate the metal.

And the strength of the aluminum to make a larger oval shape tube. Any radiator guys out there want to give it a shot? If it works, I just want a mention in your patent application…

 

Galvanic corrosion. Aluminium is bad enough when it comes to corrosion, stick it with copper and it's fatal.

 

...True that in the presence of moisture, with two dissimilar metals together, the more noble of the two will usually devour the other.

 

Aluminum radiators are totally repairable with brazing rod here is some you can buy at harbor freight It's super easy to use with about 5 minutes worth of practice
https://www.harborfreight.com/8-pie...NeGjzQQ7YyxTzSF-eXo6qkJHehHVB3ghoCbVIQAvD_BwE

 

Running champion aluminum rads in 3 different cars. Only issue I've had is my 60 f100 runs too cold even with a 195⁰ thermostat. I have cardboard blocking almost the entire radiator to have heat in the winter. I can sit in 110⁰ heat AC on full blast idling as long as I want and not overheat. Of course the shroud and good fan help with that. I had a walker in my flathead powered model a but I'd never pay that price again.