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Biggest best radiator for K5

Csm Davis

Csm Davis

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Okay so I have searched for a good thread on this subject but haven't found all pf what I am looking for.
First copper vs aluminium. Which is better in the real world.
Max size we can easily fit?
Actually mounting it, direct fit doesn't always fit.
 
copper/brass just get one for a 6.2 diesel its wider than gas . be carful you might need to find the rare 4core top plates for the rad or make your own .

aluminum cools better with less surface area like a copper/brass so I have read over the years . but be careful as there is full welded rads and epoxy sealed rads . the full welded you can tig weld to easy . . the epoxy you have to be real carefull cause you can upset the epoxy seal and be s.o.l.

also most aluminums even so-called direct fit replacement are NOT direct fit for the hold down and rubber isolator system of our stock trucks/blazers/suburbans . they require custom made setups to hold them . my griffen is NOT a direct fit bolt in for stock system
 
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My BE COOL aluminum radiator is a direct fit and badass. Tremendous change in temp control on my big block. It has served very well for several years wheeling in South Texas.
 
What are you trying to do with the radiator?

The best under "normal" conditions, is replace it with what it came with IMO. Otherwise you start dealing with fan shroud issues and as mentioned, upper mounts, and most aftermarket radiators being of questionable fit and unfortunately quality. IMO it's hard to spend the money on a "larger" radiator that is an unknown quantity. Even on here someone recently posted about two failures with a major, non-cheap name brand radiator. Anymore, unless a copper/brass fell into my lap, I'd probably just get whatever the auto parts store would sell me with a lifetime warranty. Heck, the lifetime warranty copper/brass in my truck now had the metal straps around the core rust through and fall off, never heard of that happening before, especially with so few miles and no salt.

If you aren't asking the truck to do something it wasn't originally doing (swapped in big block, lots of super heavy towing up steep hills in high temps, crawling at low speeds, etc) there is generally little need to "upgrade" the radiator. I'd posit that most overheating conditions outside of what I've mentioned are probably because the radiator is already in bad shape, and a same-size replacement would be an improvement, simply because it works. Heat transfer and flow is reduced as the tubes corrode, and generally the bottom of the radiator is worst, where you can't see it. Since many people don't change the coolant or at least make sure the anto-corrosion package is up to snuff, over time the tubes start to get bad.

The majority of what GM was doing with the "larger" radiators (save the really small/short ones) in these trucks seems to have been adding fluid capacity. The largest radiators had almost none of the additional area efficiently exposed to air coming through the core support, because they are much wider than the openings in the support. Even thickness is a trade off.

A high flow water pump won't hurt, but I would only look to that if a new radiator didn't solve a specific problem, and even then you'd be hoping for better performance, not guaranteed. Physics does not concur with being able to move water "too fast" through the radiator to cool (cavitation/flow changes are a different story but not likely with a truck engine), nor do most/all major manufacturers of aftermarket water pumps, so I don't consider that in my suggestion for high flow pumps.
 
dyeager535 said:
What are you trying to do with the radiator?

The best under "normal" conditions, is replace it with what it came with IMO. Otherwise you start dealing with fan shroud issues and as mentioned, upper mounts, and most aftermarket radiators being of questionable fit and unfortunately quality. IMO it's hard to spend the money on a "larger" radiator that is an unknown quantity. Even on here someone recently posted about two failures with a major, non-cheap name brand radiator. Anymore, unless a copper/brass fell into my lap, I'd probably just get whatever the auto parts store would sell me with a lifetime warranty. Heck, the lifetime warranty copper/brass in my truck now had the metal straps around the core rust through and fall off, never heard of that happening before, especially with so few miles and no salt.

If you aren't asking the truck to do something it wasn't originally doing (swapped in big block, lots of super heavy towing up steep hills in high temps, crawling at low speeds, etc) there is generally little need to "upgrade" the radiator. I'd posit that most overheating conditions outside of what I've mentioned are probably because the radiator is already in bad shape, and a same-size replacement would be an improvement, simply because it works. Heat transfer and flow is reduced as the tubes corrode, and generally the bottom of the radiator is worst, where you can't see it. Since many people don't change the coolant or at least make sure the anto-corrosion package is up to snuff, over time the tubes start to get bad.

The majority of what GM was doing with the "larger" radiators (save the really small/short ones) in these trucks seems to have been adding fluid capacity. The largest radiators had almost none of the additional area efficiently exposed to air coming through the core support, because they are much wider than the openings in the support. Even thickness is a trade off.

A high flow water pump won't hurt, but I would only look to that if a new radiator didn't solve a specific problem, and even then you'd be hoping for better performance, not guaranteed. Physics does not concur with being able to move water "too fast" through the radiator to cool (cavitation/flow changes are a different story but not likely with a truck engine), nor do most/all major manufacturers of aftermarket water pumps, so I don't consider that in my suggestion for high flow pumps.
Click to expand...

I concur with most of your post if i was having cooling problems but you bounce around the issue at hand and to answer your first question, cool my engine. I have probably 15 of the big copper stock radiators, but they are getting hard to replace with new copper. So looking for replacement all aluminium especially if they are better as advertised but having a hard time justifying double the price of copper. And no I will not buy plastic tanked.
 
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Better in the real world is going to be what you want to run. I'd put a copper/brass up against a good aluminum radiator and expect them to perform about the same. Or at least comparable enough that you most likely couldn't tell the difference.

You've got one poster saying Griffin is not a bolt in, and a be-cool is. Neither are "cheap" units AFAIK, so cost isn't an indicator apparently. Most of the "cheaper" all aluminum units (Champion, etc.) are not bolt ins, and things like the heater fitting or trans coolers may not be to spec either.

Aluminum is apparently NOT better at cooling than copper/brass. I can't remember if it's the actual properties of the metal, or the way they are constructed. But there is info out there that aluminum isn't better at cooling. It's just cheaper as a base material to work with, and they might do the tubes slightly differently. The amount of effort put into it's construction is why the prices are what they are for the "good" ones IMO. Edit: To not start a pissing contest, you won't find a consensus on which material cools better. Solder does not transmit heat well, but that's not the whole story. In our reality, either cools as well as the other.

Good aluminum radiators are probably just as expensive as a copper/brass radiator. I don't even know if the copper/brass are good anymore, I have no idea where they are made, and to what standard.

The only reason I can see to avoid the plastic tank units is because they are all aftermarket in our application, and the aftermarket for this component (in plastic/aluminum) is generally not performance oriented, so likely lowest-bidder results. I'd be surprised if there is a single OEM out there using anything BUT plastic tanked units, and they are warrantying the vehicles they are in, and lasting for going on decades. There is obviously nothing inherently wrong with the idea, except when done cheaply.
 
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Just my 2 cents, but I put a "Be cool" in my '70 years ago and I had to grind the support saddles for clearance on the tanks. And then just 2 years later , not that many miles, it started leaking at the tubes. I was told by them that the repair was to epoxy the leak....
Had a radiator shop do it, 6 more months, leaking again, now it has a Northern unit installed for years. It was cheaper, too.

My '90 has a copper/brass 4 row with a late 90's plastic fan on the stock clutch.
I can use the A/C while wheeling.
 
I've got a alum in my 74, forget the brand off hand. One of the cheaper ones, 3 core I think. Had to modify the rubber cushions to mount otherwise fits fine.
The mounts are more more flat than the original rad.

The filler neck sucks and doesn't always seal to the cap correctly.
Make sure the filler is welded on style.
Supposedly the newer design rads are more efficient. I know I had to go from a 180 to a 192 thermostat to get sufficient heat in the winter.
 
I used to get my rads re-cored back in the day. Now getting old OEM brass rad re-cored is crazy expensive, and hardly anyone does it anymore.
I reluctantly put in a plastic/aluminum a Spectre 730 ($160 at RockAuto) in my BBC K30. The Spectre 730 rad I got says made in Canada.
Surprisingly 8yrs later it is still doing fine and has never over heated. I have no complaints.
 
I installed a Griffin exact fit aluminum radiator in my Suburban about 1 1/2 years ago. It was very expensive. It ended up leaking where the core is epoxied to the end caps. I was not impresssed.

I just installed a Mishimoto aluminum radiator and am pleased. It does run cooler than the Griffin. It also was half the cost. I had to tweak the top brackets just a hair, but otherwise it fit. Oh yeah........had to remove two small tabs off the plastic radiator shroud to get it to mount flush.
 
Ron Davis Radiators Has a solution or will build one to your specifications for any application. They're not cheap & seldom have one they can ship when you call. Most are built to order. All are 100% made in USA from American materials, by Americans in Glendale Arizona. You'll never be disappointed in a Ron Davis Radiator.

I have a Ron Davis Radiator in my K5 and in my Power wagon & in my 3rd Generation Camaro which have notorious cooling problems in most weather. I also live in Las Vegas Nevada and it gets hot here in Summer. I also take them to Phoenix & it gets damm hot there. Zero Cooling Problems with any of them. A/C running full blast even in stop & go traffic.

Googling Aluminum Radiators v Copper or Brass Radiators pretty definitively proves aluminum is better for cooling & cheaper to manufacture. IF the inverse were true the racers with unlimited budgets would be having them built instead.

It's nearly impossible to buy a copper or brass radiator at any price. The most common exception I've found is for old classic cars and those shops are few & far between and there's a reason why.

There is a difference between a direct fit & exact fit radiator. Basically a direct fit for a given application will dimensionally fit, have correct inlet & outlet hose orientation, and transmission fittings if applicable but from there you're on your own to take it across the finish line. That usually means making your own upper & or lower radiator mounts or customizing your existing ones.

Personally, I think BeCool, Griffin and Ron Davis make the best Aluminum Radiators, but IMHO Ron Davis is King and you have unlimited options with Ron Davis for a custom built radiator.
 
Ned Kelly said:
I used to get my rads re-cored back in the day. Now getting old OEM brass rad re-cored is crazy expensive, and hardly anyone does it anymore.
Click to expand...
Just had my leaking two core OEM recored to a three core in Redwood City CA. The old guy told me he is the last one in the area (entire regional metro area) left that recores. When he goes that is it. He did say he will be doing this work until he does go. It was not cheap.
 
I have better durability with the radiators that my local shop builds vs. the new units that they sell me for the trucks at work. But everything has gone to the philosophy of " get it out the door cheaply ".. there isn't a priority of making things last.
And combine that with EPA regulations....
 
When you find a radiator that you like, if you are running an auto trans. consider using a big trans. cooler and reduce the load on the cooling system. I did and it made a big difference. Made my trans. last almost 250K so far and I did some heavy towing, campers, an offshore boat, trailers, Fords, etc.
 
I have a KKS brand aluminum radiator from atomicradiator on ebay, it has solid tanks and 1 1/4" tubes. Haven't started the engine yet so no word on how it cools but it was a good price and a nice radiator.
 
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