The Stovebolt Site Forums The Shop Area Engine Shop Replacing my radiator?

When I had the engine in my '53 3100 restored 4 years ago the mechanic replaced the copper/brass radiator with an aluminum one. I asked him why he used aluminum as I wanted to keep it close to stock and he said because aluminum was better. Now I'd like to go back to copper/brass and I need some help getting the correct radiator. My engine is a 261 and the radiator in it is a Champion with 3 rows of tubes and measures 19-3/4 x 25-1/2 x 2-5/8.

My questions: 1) is it a mistake to replace the aluminum radiator? 2) How do I choose the size of the replacement? If I search by my model year the radiators are designed for the original 216. Should I just find one the same size as I have? It seems a bit tall.

Thanks for your help!

Hi Denny,
It is a mistake to replace the aluminum radiator in my opinion but please understand I live in Dallas (which some have called the waiting room for hell, weather-wise). We get summer apx 8 months a year so maximum heat transfer is of paramount importance, and the old copper/brass radiator falls to second place behind the aluminum one. Since your engine (a 261) wasn't available when your truck was made and since you have an alternator rather than a generator, you've already stepped outside the parameters of "restoration." If you have a 3 row aluminum radiator I'd leave it.

Well, there are lots of opinions, but from my perspective, aluminum is cheaper, not necessarily better. QC for the ones that are offshore sourced can be highly variable. There are a few companies that make good quality aluminum radiators with a stamped top tank that look correct, like Engineered Cooling Products.

But, a well-tuned 261 should be just fine with an OE-style radiator, and the cooper/brass units cool very well and look right, IMO. I haven't seen a copper/brass unit that is a better value than the Chev's of the 40's Radiator, but I've not done extensive shopping, either.

Hope this helps.

Doug

Jon, just to be clear, I was typing my response while you were apparently typing yours, so I wasn't aiming at your post. I should have mentioned, Champion radiators are generally good quality, so leaving it is certainly a good option. I'm assuming there isn't an underlying cooling issue we haven't heard mentioned.

Cheers!

I have 2 of those aluminum radiators which have the top tanks which look very original. I painted the top tanks with metal etching primer and Rustoleum semi-gloss black and it is hard to tell them from the original brass ones. Both trucks are Advance Design with 350 engines in them, and they stay within the 180 mark on the gauges. Most of the time right on the "8" of the "180", but it will hit the "0" in traffic on a hot day. Not too shabby.
Carl

Thanks for the considerate note, Dave. I didn't take offense at all. I've had excellent results with the aluminum and with the old copper/brass one, I had years of overheating problems. Particularly in slow-moving traffic which as you know we have a lot of here. At speeds above 40 it was ok but not at speeds below 40, despite having replaced the core with a new one. Idling at a stop light or crawling along in traffic in any month between April and mid November the needle would go over 200 predictably. Now it stays around 180~185.

Well, I anticipated a variety of opinions and these are great - keep them coming. I meant to include this picture of the radiator to see if you guys think it looks too "tall". Thanks[img]https://www.dropbox.com/s/bsnvzw9kdg4v7eq/Radiator.jpg?dl=0[/img]

Technically, even when you change the oil it is no longer original. I have aluminum in my 54 and I would not go back.

Aluminum 4 row in my ‘62 C-10 350/700R4 and with the flex fan it stays around the 180-185 range. I like it.🛠

That radiator looks just fine, Denny.

Aluminum or copper, I'd rather have a larger 3 row, vs a smaller 4 row. Better water flow.

Thanks for all the helpful comments. I think I'm convinced to keep the aluminum radiator as it's working well but I like Carl's idea of painting the top tank. I imagine that you sprayed those tanks before you installed them, Carl, so I'll need to pull this one - but it saves me several hundred bucks & seems like a good compromise.

+1 for painting the top tank. Aluminum is a poor substitute for copper in the heat transfer department, but a new copper radiator will make your checkbook choke! Copper is the world's best heat conductor, while the only advantage aluminum offers are lower cost and lighter weight. If you're not having overheating problems, just paint the top tank and drive on. I'd recommend semi-gloss or flat black paint.
Jerry

Flat black BBQ grill paint is an excellent rad paint. After abit of research ive found this out when looking to paint an aftermarket rad designed to fit a model A frame with a flathead ford motor. It was also aluminum.

Making the paint stick and stay put on aluminum is the tricky part. Back before the tree huggers got their manties in a wad about the chemistry, zinc chromate primer was the "go to" method for preparing aluminum for paint. Airplanes all over the world, including virtually everything the US Air Force flew, got coated in zinc chromate before the color coat got applied. I'm pretty sure there's some sort of acceptable substitute nowadays, but it's probably not as effective.
Jerry

"Recent studies have shown that not only is zinc chromate highly toxic, it is also a carcinogen.[17] Exposure to zinc chromate can cause tissue ulceration and cancer.[1][3] A study published in the British Journal of Industrial Medicine showed a significant correlation between the use of zinc chromate and lead chromate in factories and the number of cases in lung cancer experienced by the workers.[18] Because of its toxicity the use of zinc chromate has greatly diminished in recent years." (wikipedia)

They could have tried to find a way to protect the factory-workers?

Yes, a rat fed its own body weight of zinc chromate every day eventually became ill.
Cost of product replacement of failed aluminum parts: $$$ billions.
But we saved some rats.
Progress!

?

I scuffed what I needed to paint (the top tank and the sides) with a red Scotchbrite pad, used self etching primer, and black paint, all Rustoleum rattle can products. I did not paint the fins since there is no way to prep that for paint, and I did not want to interfere with air contact with the core.
Carl

I'm with Jerry on the zinc-chromate, I used Rustoleum zinc-chromate primer and topcoat on a snowplow moldboard 35 years ago and it's still holding. A little toxic stuff never hurt anyone, just 'cause I'm 25 and look 90 and can't see, hear, smell, or think 'don't prove it's bad!