New aluminum radiator

[Buffalowed Bill]

What I'm really interested in finding out what people think about using the newer aluminum radiators in their vintage driver cars. I admit to using these in my daily drivers, which are all about twenty five years old. It's hard to ignore their availability and cheap price, but my mechanic, nephew has experienced a high failure rate, some of which failed within the first year.

 

This weekend a friend was asking about an aluminum radiator for Studebaker Lark, that he is working on. As an alternative, I gave him the name of my radiator guy who might be able to repair, or recore  his original. He countered by saying that people have told him that the aluminum rads are better in every way. This just doesn't jibe with my experience. I still have a dozen cars, from the early thirties to the mid fifties, that still are using their original radiators. There did seem to be a drop off in the quality of the cores used, after about 1955, but my recored rads have held up well. Comments appreciated.-Bill

 

[Matt Harwood]

I've had a large number of cars come through with modern aluminum radiators so I think I have a pretty good grip on their pros and cons. As with most things, it really depends on how it's built. There are some companies who just take a standard core, cut it to size, and weld on tanks to fit a particular car. That's what most of the inexpensive aluminum radiators are. They don't look at core thickness or surface area or tube diameter or anything like that, just "will it fit in that car?" Those are probably the ones that have marginal performance and higher failure rates. But they are affordable.

 

Then there are the good ones that are properly sized and designed to replace the original radiator. They rarely look like the original, but they cool at least as well and usually better. They have a greater fin-per-inch count and tubes that are not just more numerous (more passes) but shaped differently (flattened oval vs. round). They are heavier because the tanks and mounting hardware is more robust and the filler neck is often billet welded on rather than some kind of spun aluminum thing. You will pay a premium for these ($800-1200) but they work better. They do not usually look even close to OEM and you will sometimes need to make modifications to make them fit. They're close, but since they were designed to cool well in a particular car, they worried less about making it OEM in appearance and fit. They assume a guy using it will be skillful enough to install it.

 

There are still brass/copper radiators out there that work just fine, and if you can get those for your car that originally used such a thing you might be better off. They're not as efficient as aluminum in many cases, but they're durable and they look right and if they're designed properly they'll provide plenty of cooling so the difference is largely academic.

 

Personally, all my old cars get their original radiators re-cored by an old school radiator guy who has access to like 45 different types of OEM cores so he can get exactly what it had originally. He re-uses the original tanks if possible. He does flow tests and he does pressure tests. That, to me, is the best possible radiator for an old car. I had the radiator in The Car Which Shall Not Be Named re-cored at a cost of almost $1000, and it used unique 5/8-inch tubes that the radiator guy had only seen on big luxury cars of the '30s, which said to me that it was correct, just plugged. He got the right core, put it back together with the original tanks, and it would have cooled the engine without any effort. I never tested it, but I can only assume that with a fresh core of the correct size, it would have been superior to anything else I could have cobbled together and stuck in there. The factory engineers are still the smartest guys in the room. You think Lincoln customers were putting up with overheating engines in 1935?

 

If you don't care about absolute authenticity, the high-end aluminum units can work well if they're installed properly and have enough air moving through them. It really does depend on the application--trying to keep a big block with A/C cool in a Nash Metropolitan, well, I don't know if there's any radiator big enough to make that an easy job. If you're cooling a 289 in a Studebaker Lark, a good aluminum core from a company like Fluidyne should have no problems keeping up and should last a lifetime.

 

Cheap radiators are cheap. Expensive radiators are good. The construction is less a factor than the cost, because all other things being equal, an expensive radiator will significantly out-perform a cheap one, regardless of what it's made of.

[TexRiv_63]

IMO putting a generic aluminum radiator into an older car is an internet era solution. People read on Facebook or online car forums that aluminum is the magic solution to all cooling problems and the knee jerk kicks in. If you are building a race car or modified street car with 1000 horsepower perhaps a massively oversized unit is needed but for normal cars the original factory engineering is usually quite effective. I have read a number of sources that say the brass / copper radiators are MORE efficient that aluminum assuming they are in good condition. When I replaced the rad in my factory a/c 63 Olds Starfire I bought a new brass/copper unit from U. S. Radiator that was an exact visual replacement for my original but uses a high efficiency core that about double the effective surface cooling area. Never a cooling problem in Texas summers!

 

 http://www.usradiator.com/

[JACK M]

Its a money thing,

To get an original radiator repaired these days is very expensive.

The aluminum radiators are relatively affordable.

I have use a few, they work fine.

[Restorer32]

Assuming the area exposed to the coolant is the same, copper is better at transferring heat than aluminum.

[c49er]

Now how long will an aluminum radiator last compared to a copper radiator assuming average cooling system care is done?

Will a replacement aluminum core be available in 10 years for those who keep their cars?

[JACK M]

I wouldn't consider coring an aluminum radiator, It would be cheaper to simply replace it.

I put one in a 57 Chevy pick up about ten years ago and its doing fine today.

Got one in the 46 with the Hemi.

Edited August 13, 2019 by JACK M (see edit history)

[Bloo]

1 minute ago, Restorer32 said:

Assuming the area exposed to the coolant is the same, copper is better at transferring heat than aluminum.

 

Yes. And common wisdom says that when comparing radiator cooling capacity, pound-for-pound aluminum wins. In square inches, copper wins. Thickness of core only helps up to a certain point, and you hit the law of diminishing returns VERY quickly. If you are limited by air intake area, as you usually are in an antique, copper is theoretically better.

 

In many cases, the cars already ran too hot, and now everybody wants to hang on air conditioning.

 

The argument from the other side is that the solder used in a copper radiator does not conduct heat as well as aluminum, and that aluminum radiator technology has progressed to the point that aluminum has surpassed copper.

 

I have a first generation Miata. In Miata circles the idea that aluminum has surpassed copper has taken over, and there are all sorts of proven (and expensive) high performance aluminum radiators available. Although the high performance some of these is undeniable, I am still skeptical that technology has overcome such a huge difference in the metal. I have a copper radiator in my Miata. I don't even think you can buy one anymore.

 

A copper radiator is at least theoretically repairable forever. With all of the radiator shops disappearing, it is questionable whether you will find anyone to do it in the future. But at least it is possible. You might have to make some elaborate setup and do it yourself if it needs major work.

 

Repairability of aluminum radiators varies. On the plastic tank type, you can theoretically take the tanks off, rod them out, and re-crimp them. The trouble is that plastic tanks rot, some worse than others, and you really can't depend on them being around forever.

 

On the aluminum radiators that have aluminum tanks welded on, such as are popular in the musclecar world these days, it would seem that you could just cut and weld them as necessary. I asked our local radiator guy (when we had one) about this. His comment: "it would be easier to just make a new one".

 

For now I will stick with copper. Your mileage may vary.

 

 

[Spinneyhill]

I think the metal is not so relevant for heat transfer because an automotive "radiator" cools by CONVECTION, with very minor conduction and almost no radiation (it is a puzzle why they are called "radiators"). Yes, you need to get the heat from the water to the metal surface, but the temperature and speed of the air through the "radiator" is the important part of this equation. The thickness of the metal is very small so will have a minor effect on cooling.

 

The most important aspect with aluminium systems is the corrosion protection, esp. at the water-air interface in the top tank. With pressurised systems, that interface is in a plastic tank to the side somewhere.

[c49er]

Some of the old copper brass radiators are a real piece of art to look at and can last 75 years or more....modern aluminum .... doubt it.

Edited August 14, 2019 by c49er (see edit history)

[Buffalowed Bill]

Thanks everyone for responding. There's a good deal of information here, I hope people are paying attention. Most of it mirrors my own preconceived notion, regarding the differences between copper and aluminum, but I just didn't have the real world information to go along with it.

 

When a friend says that his information indicates that aluminum is better in all ways to copper, I feel inclined to push back a little. I have seventeen vintage cars (50-89 yrs old) which still have their original radiators in place. These are the original rads, that came in the car when they were new, not replacement units. Many of these, and maybe all, have had some service done to them over the years, but I enjoy saving the original when possible. I wonder if any of the aluminum radiators will still be in place in ninety years or even fifty years from now?

 

Years ago it became a challenge to find, and keep a technician willing and able to help with the challenge. On several occasions I had shops tell me that they didn't want to mess with the original, without even looking at the rad. Time for another radiator shop. Some may consider saving the original a fools errand, I do not. Sometimes the seemingly simplest and easiest solution may not be the most rewarding. 

 

Bill

[TexRiv_63]

On ‎8‎/‎14‎/‎2019 at 1:47 PM, Buffalowed Bill said:

 I wonder if any of the aluminum radiators will still be in place in ninety years or even fifty years from now?

 

 

Aluminum radiators are designed to be replaced and thrown away rather than repaired like most other modular components on newer cars. Nothing is "repaired" anymore.

[JACK M]

On ‎8‎/‎14‎/‎2019 at 11:47 AM, Buffalowed Bill said:

I wonder if any of the aluminum radiators will still be in place in ninety years or even fifty years from now?

 

I doubt any (or at least most) of us will be around to see.

[Buffalowed Bill]

Jack  you are certainly right, but the cars are an historical legacy, the closer they are kept to original the better their story.-Bill

[JACK M]

Don't take this wrong but, Historical legacy doesn't do much for me if I cant drive it.

I understand all that perfectly original stuff and those that pursue it.

But I am a doer so avoid the long term projects that seem to be waiting for one part or other all the time.

If an aluminum radiator will get it on the road so that I may enjoy it so be it. It could certainly be reversed.

Aluminum radiators would not be my first choice in most cases, but they have come to be an affordable alternative.

 

Where I live all but one radiator shop within 30 miles or so have closed. I take some business to the remaining guy, but even he tries to sway his customers to take the easy way because he is sympathetic that he has to charge so much .

He is an old guy and I don't know if the hot shot kids in his shop will be able to do his quality of work when he finally retires.

Its a combination Radiator and glass shop and all family run. I like to do business with this kind of shop. However I fear that it may become just a glass shop.

[Bloo]

2 hours ago, JACK M said:

Don't take this wrong but, Historical legacy doesn't do much for me if I cant drive it.

I understand all that perfectly original stuff and those that pursue it.

But I am a doer so avoid the long term projects that seem to be waiting for one part or other all the time.

If an aluminum radiator will get it on the road so that I may enjoy it so be it. It could certainly be reversed.

Aluminum radiators would not be my first choice in most cases, but they have come to be an affordable alternative.

 

I hear ya, but throw the old one in the attic or something. You might need it someday.

 

I have that copper/brass thing in my Miata because I think it is a much better bet for repair in the future when all the aftermarket support dries up. It isn't stock. The original radiator was aluminum, with plastic tanks. It cracked lengthwise along the top tank. As it turns out, that is a common thing. The normally black plastic (on those particular radiators) first turns brown, and then green. Once green, it is in danger of literally falling apart.

 

Once in a past life, I worked on Volvos for a while. There are 3 possible brands of original plastic/aluminum radiators on the Volvo 240. One of the three, Blackstone, is prone to rot. The hose connections will literally fall off. They don't even change color to warn you something is up, they look fine. POOF! All your coolant is on the ground.

 

My local radiator guy was fixing a lot of the aluminum/plastic ones in his last few years, mostly for big trucks. But, he considered the all aluminum units disposable.

 

At least with copper there is some chance I will be able to fix it myself. I have done minor repairs in the past with just my torch and some nice runny flux. I even soldered up a hole in a tube in the second row of a three row radiator once (1970 Dodge). Yeah, that was dumb luck, and I've never been able to repeat that performance. Still, there's a chance. If the whole radiator needs to be built from scratch because the one in the car is an unrepairable type, that sounds like a bigger problem to me.

 

 

[Buffalowed Bill]

Bloo,

 

Agree with everything that you just said. 

 

Jack,

 

Your car your choice. I don't limit my driving because I choose an original radiator over one made from aluminum. I really don't understand the logic that says by choosing an original radiator over aluminum, I am also choosing to not drive my car.  Or to reverse it, I can drive the car with an aluminum radiator, but not with an original.

 

There is little doubt that our cars will outlive us. Some of us may not care what happens to our cars after we are gone, but I care. I want the next owners of my cars to have the complete car. I don't want to make them have to search for parts just because I was too lazy to hang on to them, or maybe I had a chance to make a buck on a part. What better way to save a part then to refurbish it, and use it in the car that it was made for.

 

Just had a thought. In forty years, or so, when the world may have made the switch to electric transportation, of some sort, and what if there are no more aluminum radiators to be had, and if the original radiator had been discarded, what would happen to the car?   

 

[JACK M]

No, I would not toss it.

But I have probably twenty old radiators kicking around that aren't good for anything.

None are rare and I don't have any original cars that need a radiator at the present.

The non original cars that I have, (hot rods  ) I just use what works.

Fun stuff !!!

 

[mfrank]

I manufacture aluminum radiators for vintage cars, so allow me to give you the inside scoop. 

 

First if all, your first consideration is aesthetics vs practicality. With only a handful of exceptions, aftermarket aluminum radiators won’t have anything like the look of the original. If your goal is preservation of a classic, you really should recore your stock radiator. Nothing looks more ridiculous to me than an aluminum radiator in an otherwise original and well preserved old car, and I make these things.

 

OTH, if you are looking for a practical radiator for a driven car, copper is expensive, and more importantly, becoming very hard to find. I can’t think of a single old fashioned rad shop still operating in the Hudson valley. So you will be at the mercy of specialists and a diminishing old stock of parts. Not an unfamiliar situation for the restorer, but not the best for the practical driver. A custom made aluminum radiator will last 20 years or more, but will not be repairable or rebuildable.

 

As for why aluminum works better, it’s not the metal that matters. The secret is fin-tube contact. This is optimized when you have a small number of large tubes. So going from a radiator with three rows of 1/2 tubes to a radiator with a single 1.5 inch tube is actually going to improve heat transfer 15%, regardless of material. Most of my cores have just two rows of 1” tubes. When you enlarge the tube, the walls have to be thicker, and the advantage goes to aluminum because of weight. The rest of it is that there has been a lot of development of fin materials, and modern corrugated fins offer more surface and create more air turbulence than old fashioned accordion pleats. That’s the engineering part, everything else is rumor. Finally a new radiator is cleaner, no matter what it’s made of, and that has to help.

 

Because there are is so much ‘common knowledge’ from the days of copper, there are a lot of bad products out there. Beware of Chinese radiators that advertise four row aluminum cores. These abound, but they are not worth the price, however cheap. Again, fewer, larger tubes is better than more small tubes. And higher fin count also means less air flow, so again,  what you remember about copper doesn’t help.

 

Finally, corrosion. Here’s the secret: 50 /50 coolant. Don’t listen to the water cools best crowd, and never mind that you never drive in winter. Antifreeze does more than protect against freezing. I recommend a low silicate antifreeze, like Zerex G05, rather than a dexcool. But whatever you choose, stick to a 50/50 ratio.

[Buffalowed Bill]

Thank you mfrank! Really adds perspective to the discussion.

[Restorer32]

Aluminum radiators are better, disc brakes are better,  12 volt electricals are better, yadda yadda yadda