Aluminum radiators? How do you feel about them?

Actually squirrel I think we agree on this point. The rad in my stude still has the original core and it is fine. [actually we agree on a lot of things but someone has to be the devil's advocate]

From a performance standpoint I like the aluminum radiator. They do make aluminum radiators for some of the more popular cars, tri-5s chebbys for instance, that look like originals radiators but the price is right up there with the br*** ones. In that instance if I could find one I would go with the br*** unless it was just a matter of saving a couple of pounds. Asthetically an original is going to be better of course.

 

Yeah, of course you know more than someone that has been building custom cooling systems for 50 years. I tried to say it nicely but now, shut the **** up if you don't really know what you are talking about!
If you think coolant can not move too fast through a system the basics of physics must be a black art to you.
Try the reverse of this heat dissipation, quickly touch a frying pan at its hottest, then place your other hand on there for a full second.
Now compare the burns you have.
Just why do you think you have a much worse burn on the hand you placed in there for a full second?

Honestly some people scare me.

Weasel, thank you.

Doc.

 

Damn Doc I had to go back and read the post to make sure you weren't talking to me. I'm still not sure you weren't talking to me. So I went up and did the frying pan thing. That hurts like hell buddy and stinks too.

The wife has a copper pot she uses for making jelly, and I got an aluminum pan left over from camping out and walking around a lot. I'll try those this afternoon with my other hand.

What am I trying to figure out?

How the hell are ya buddy?

 

Hell no mate, I wasn't talking to you on that post!! It just annoys me that some people think they know more than another that has been doing something all there working life!

What are you trying to work out? Cooking lengths for steak....er......right??
Let me know how the jelly and and camping pot's go!! Hey, maybe we should look into most efficient fan shroud matereial.........
I'm doing good mate, hope life is treating you well too.

Doc.

 

Life is good. A minor set back or too but no hill for a stepper.

I guess in this case it would be cook lengths for pork chops, anyway that's what it usually smells like when I burn the **** out of myself.

Glad to see you're still on this side of the gr***.

 

The size and weight of the vehicle also enter into the equation. If you have a 20,000 lb vehicle, it will take a lot more power to accelerate and keep it moving, compared to a 5000 lb vehicle. Since the engine is making more power to move the heavier vehicle, it is making more waste heat, and needs a larger radiator. I'm guessing "the radiators these engines use" are installed in bigger vehicles than your car?

My guess is you'll probably be fine with the stock Caddy radiator in your project.

 

just bought one for my 51 chevy on ebay. its made by champion. 3 row cools up to 750hp came with a 16" 2500cfm electric fan for 250 bucks. havent tried it out yet. but inspected it all over and looks like really good craftsmanship

 

humm one vote for yes it will work.....now if i can convince myself..ha ha ha

 

Shut the **** up? Ha, not me.

A littler logic will set you free. Hold your hand on that pan all day, the pan will not be cooled much by putting your hand on it. If you really want to cool the pan pour water over it. The faster you pour the water the faster the pan will cool off.

 

BWAHAHAHAHA!!
Didn't get past grade school huh? Ok, pour the water in, let it sit for a second before pouring out and feel the heat in the pan, nice and cool.
Now pour out the water immediately, now touch the pan. Nice burn you have there.
If you were continually renewing the water with cold water you would be right. But where does the coolant go once exiting the radiator? Right back into the motor where the heat is renewed. Now if the coolant travels through the core too quickly it has NOT cooled sufficiently and the motors temp will rise faster and will not cool.
It is kind of simple really when you think about it.

Doc.

 

But if it doesn't have time to lose much heat in the radiator, it also doesn't have much time to pick up more heat in the engine.

The most important factor is the height/width of the radiator....

 

Workmanship aside, there are pros and cons to different radiator materials and designs. Although copper & br*** conduct heat better than aluminum, the design and construction of alumunum cores maks up for a lot of that. Aluminum isn't inherently bad. Heavy trucks have aluminum radiators that endure hundreds of thousands of rough riding miles with very few problems. In that application aluminum radiators are actually more durable than copper/br***!

 

Wow, Lots of great tech in this thread. I agree with Doc that too fast a flow will minimize cooling efficiency. That aside, I'm not nearly the die-hard traditionalist that most here are but, nothing looks worse to me than a period perfect hot rod with an aluminum radiator. Sorry, but I see folks go to such great lengths to acquire the right parts from a particular era (eg. clamps, wiring, hoses, fasteners, etc.) then take the apparent "shortcut" of using an aluminum radiator. It just looks wrong to me.

 

I spent eight years testing cooling system components for AMC Jeep. The copper-br*** radiators usually won the performance tests. However in the end the "Bean Counters","Weight Police",and politics always won out. Warranty failure rates were much higher on aluminum radiators.

 

i have one from superior and it works pretty well. I painted it black so it doesnt stick out.

 

Figured that the water would need to be in the rad for a little while to get cool...because that's it's job (?)...because isn't the engine what makes the water hot? If it just ran straight through the rad back into the engine what does that accomplish?

(weird **** I learned in engineering school...not braggin'...just trying to apply logic...)

edit: oh....looks like doc watson covered this....i'll go back in my hole....

 

Sounds like the bottom line here is there's no right answer... Aluminum is easier to fab, modify and repair (if repairable). Copper/br*** is more traditional, cools slightly better (apples to apples) and has less galvanic corrosion issues. Just like most issues, everyone's opinion is based on past experience.

I like br*** and use them whenever I can, but they are a ***** (and expensive) to get custom fabbed.

 

Wow, somebody got up on the wrong side of the...world...today. But you're absolutely right (as you should be). Most cooling problems involve too little block pressure or too rapid coolant flow (obvious plugged radiator or stuck t-stat notwithstanding).

And I stand behind my remark about br*** rads being tougher and more expensive to have fabbed...unless you know someone in the business.

 

The thing is, there is no apples to apples comparison. Aluminum cores aren't made the same as copper/br*** cores. That's why cores made of "inferior" aluminum can out cool ones made of copper/br***. Modern aluminum cores are fully brazed, which improves heat transfer getween the tubes and fins. And some aluminum radiators have the more efficient elongated airfoil shaped tubes. There are copper/br*** core designs that are in the same ballpark efficiency of a typical aluminum core. But those cores are expensive, and most aren't made that way.

 

I don't know that aluminum is easier to repair and it is certainly more expensive to repair. I mean unless you are a stone wizard you have to own or have acess to a TIG welder to repair an aluminum radiator where as all you really need to do most repair jobs on a br*** or copper br*** radiator is a light torch and some silver solder or soft solder in a pinch.

I have fabbed both and don't find that either one is any easier to fab. Iether can be formed with simple tools.I prefer copper or br*** if I must hammer out a compound shape.

Both will cool what you need cooled so it really comes down to what you are after. If asthetics is important and the money is there than I would suggest br***. If economics is important and asthetics isn't important, or if weight is important than I would suggest that aluminum is your answer.

I have an aluminum for a '62 that I'm putting together. Weight is a minor issue and when I purchased the rad I was a little low on cash. Bought an excellent unit for about half of what it would have cost me to have my original recored.

On the other hand I have an original radiator for another project that really wants an original or original looking radiator. Its in good shape so there is no reason to go looking for a different radiator.

I guess its all a matter of what the radiator needs to do for you.

 

Doc,
If you have been doing the sdame thing for 50 years you must have reached the point where you realize one can never know everything.

Increasing coolant speed through the radiator does reduce how much heat it can give up on the way through. But, when the coolant is moving faster, in a given period of time that coolant will make more trips through the radiator. The other part of the equation is that the faster moving coolant has less time to pick up heat from the engine. But again, that coolant makes more trips though the engine. Think of it as a gear ratio. When you speed up the radiator part of the system the engine part of the system changes proportionally. So, a balance is maintained.

Some engines will overheat without a t-stat. People often ***ume that is due to the not enough time in the radiator situation you mentioned. The real cause is that increasing coolant speed may alter circulation patterns, resulting in overheating.

 

I was referring to the fact that more fab shops are probably set up to TIG aluminum than correctly fab br*** tanks and solder br*** radiators. That was more for the guys who pay to have it done as opposed to doing it themselves...

 

i got an aluminum that was good for years now it leaks in a bunch of places. I gotta pay for someone to tig weld it or get a new one. I could tig weld it but i still think it would leak as im not talented enough for that thin and complicated of a job

 

No matter what the radiator is made from air flow is one of the most important things.
Use A good fan and shroud. Make sure the rad's not pulling hot air from the engine compartment back though. A closed system and over flow tank is important too. It all adds up.

 

My '36 with a Cad 472 runs 195 to 200 now with the aluminum 2 row '66Mustang radiator, as oppossed to 220-240 and NO ability to set and idle at any ambient temp with the original '66 Mustang copper 3 row. Best money I spent on the car, for anything.

Brian

 

I have a Ron Davis aluminum radiator in my 31 running a mild 327. Never had a problem in 3 yrs. Pricey but I would do it again.

 

Q = mc(Th-Tc) That is the formula for heat transfer in a non-phase changing system. the m and the q have dots over them, which makes them rates not quan***ies. If you increase the m*** flow rate, you increase the rate of heat transfer. Period.

 

hey!...

is that Traditional math? or this new **** the kids are talking about?

 

Not really. That's Fundamentals of Physical Science 101, sinch Christ was a corporal.

Yep. Consider a system that won't cool as I would like, say it creeps up above 220 with a 180 thermostat on a hot day at a given highway speed. I can fix that by simply increasing the flow rate through the system by changing pulley size on the water pump, ***uming of course that the pump don't cavitate.

OR........ the no-brainer approach would be to increase the cooling capacity of the system with a larger radiator. Anything I do to slow the flow rate would have a reverse effect.

 

I don't know, I learned it in Nuclear Power School, but I figure if it works on a nuclear reactor, it ought to work on a flattie too!

For years I bought into the "water moves too fast" thing too. Now, I read this in a car magazine so it is suspect, but I read that the water moving too fast thing stemmed from when the 55 chevies came out. They would rev high (factory solid lifter cams) and cavitate the water pumps and then overheat because flow dropped off. So, the quick fix (in the hot rodder's mind) was to pull the thermostat so there was no flow restriction there. Well, what this did was move the high pressure point from the top of the engine (where you want it, prevents vapor pockets in low flow areas) to the top of the radiator. Now, sbc water pumps can produce up to 60psi at full song. This is obviously much higher than 7# that the radiator cap was rated for, so the motor would push all the water out and overheat. So people slowed down the water pumps, they quit cavitating, no one had to pull the thermostat, and the engine stopped pushing out water, so it stopped overheating. While slowing down the water pump was the right thing to do in this instance (you should pulley for a water pump speed of around 6000 rpm when you hit your rev limiter) the reasons people thought of to explain it weren't correct.

There are engineering formulas to determine minimum radiator size, and derivations to figure minimum airflow requirements for a given radiator size, but they use unitless coefficients and other esoteric stuff, and aren't that useful for us the average hotrodder, plus I don't remember them that well .