2500HD Replacement Radiators - Is thinner better?

[snowblind]

Hi All.

I'm replacing the radiator in my Suburban 2500HD and I discovered some "interesting" issues. The original radiator has a nearly 3" thick core. ALL the replacements I could find have a 1.25" core. The word from the manufacturers is new/better tech has the thin-core achieving BETTER cooling that the thick core. Really?

I tried ordering the $550 OEM unit direct from GM but on arrival we discovered that it now has the same thin core and also has no drain cock installed. Talk about cheapskates. How much does it save to have no drain?

In the end I went with a Spectre brand radiator from Autozone since it was only $330 and comes with a lifetime warranty. I sure hope it keeps the big 8.1 cool.

Does anybody else have any experience or thoughts on this?




Best regards,
Matt

 

[ExplorerTom]

I'm skeptical. Water to air cooling is done via surface area. More surface area = more cooling.

I just put a Mishimoto on my Expedition and it's thick like the factory radiator.

 

[DailyExpedition]

I’m going to upgrade mine pretty soon to a specter radiator from Summit that has the thicker core about 2 1/8 inches thick, (which is better) it may also fit your rig as long as your current one is 34 in wide and 17 in tall, which is what most of the radiators for Chevy is unless it’s a diesel I believe. And at only $113 from Amazon or $135 from summit it’s great and it has a drain and tranny cooler and engine oil cooler. It’s a Spectra CU624 check it out


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[Scoutn79]

Was the old radiator brass? The newer (relatively) aluminum ones have wider tubes that are supposed to have more surface area when you include the fins spacing. At some point the thicker radiator would be a hindrance since it makes it tough to draw air through a thicker core (restricted air flow)and by the time the air gets to the back it is pretty well heated up...Just a WAG about your situation.

Darrell

 

[DailyExpedition]

Was the old radiator brass? The newer (relatively) aluminum ones have wider tubes that are supposed to have more surface area when you include the fins spacing. At some point the thicker radiator would be a hindrance since it makes it tough to draw air through a thicker core (restricted air flow)and by the time the air gets to the back it is pretty well heated up...Just a WAG about your situation.

Darrell

In theory what your saying would work, and to an extent it does, but really only on the highway, however during hard use especially here in Texas during the summer using the AC and stuck in traffic it’s pretty anemic. The smaller radiator will cool faster and will make the thermostat cycle more often, the larger will take longer to cool but will flow more coolant per cycle. At the same time when I was growing up my Pops always had the big 4 core radiator in his trucks and we never overheated, and we moved a lot! Imagine a 1976 Chevy 3/4 ton 4x4 pickup with 4.10 gears 6in lift with a freakin full grown horse in the bed, towing a 26ft Airstream trailer through the mountains to Arizona. That was an interesting trip


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[marshal]

if it makes you feel any better, this 425 horsepower 6.4L hemi in my truck is cooled by a 1.5" thick radiator. granted, it is massive in every other dimension...

 

[vintageracer]

As stated above the "new" aluminum core radiators do kool better in a smaller package than the old copper/brass radiators . In most instances the tubes in the aluminum radiator are 1 inch wide or larger versus the 1/4-3/8 inch wide tube for a copper/brass radiator.

Although aluminum is naturally not as good as copper when it comes to thermal heat transfer the ability to make the aluminum radiator with much larger tubes than is possible with a copper/brass radiator is the key factor. This manufacturing change makes a big difference in the surface area required for more efficient thermal heat transfer or in simple terms better cooling performance. As such a modern aluminum core radiator can be much thinner than a copper/brass radiator and achieve the same or greater cooling efficiency. Given the wider cooling tubes in the aluminum radiator they are also much less prone to clogging up than a copper/brass radiator. Personally I have never had a modern radiator leak from a failure in the aluminum core. Generally the commonly used plastic side tanks fail long before the aluminum radiator core.

Early on a lot of aftermarket racing/high end aluminum radiators with aluminum tanks used epoxy to assemble the cooling tubes to the radiator core. Ron Davis Racing Radiators comes to mind. Bad idea that did not work that well. It's been 10+ years since I have seen an epoxy aluminum radiator so this should not be a problem.

Mishimoto makes a good product if you are looking for a larger aftermarket aluminum radiator. Some times you will find an OEM replacement aluminum radiator that's labeled as Heavy Duty cooling (HD). Generally they will have 2 large aluminum cooling tubes and as such will be a thicker radiator that looks more like the copper/brass radiator of old. You will never have cooling issues if you use one of these upgrades if available and the rest of your cooling system parts are in good condition.

Always remember to replace the hoses, clamps, thermostat, water pump and make double sure you get a NEW CORRECT RADIATOR CAP for your application. Given the newer modern cooling system designs that may mean a trip to the dealer for a NEW OEM correct radiator cap.

Yes the radiator cap can be that important in today's modern cooling systems. The wrong radiator cap can easily cause an overheating issue given the complexity of some modern radiator cap designs.

 

[Hillbilly Heaven]

Surprised no one mentioned Champion Radiators

 

[snowblind]

Was the old radiator brass? The newer (relatively) aluminum ones have wider tubes that are supposed to have more surface area when you include the fins spacing. At some point the thicker radiator would be a hindrance since it makes it tough to draw air through a thicker core (restricted air flow)and by the time the air gets to the back it is pretty well heated up...Just a WAG about your situation.

Darrell

Old one was aluminum with plastic end tanks. New one is the same construction. It looks like the new one might have a slightly higher fin density but not twice the # of fins.

The radiator for the GM 2500s includes a trans cooler and an oil cooler so you can't run a "standard" replacement rad without blocking lines or adding coolers. Mishimoto don't make any rads for the Chevy gas trucks.

The new rad is in the truck now. Time to see how it works.


Matt

 

[chilliwak]

I purchased an aftermarket aluminum fan from a supplyer in the US, but it was a chinese built rad. Normaly I am very skeptical about stuff from China but it cools much better and the price was right. But it does have a very thick core. Much thicker that the original that it replaced.....

 

[AlexCold]

I just bought a radiator for my 2500 as well and as you said it is thinner. I believe this is due to better cooling design methods so they could minimize material cost and weight. I don't doubt the cooling ability considering I believe they used this design on the gmt900 hd gas trucks as well.

Btw the a.c. Delco radiator was only $220 on Amazon.

 

[snowblind]

Some quick feedback. Thin radiator is cooling VERY well so far.

It definitely flows more air. I know this because the temperature controlled electric cooling fans are NEVER turning on. They turn on with AC but during stop & go driving in 60º-70º temps the fans never turn on and the temp stays below 200º.


Matt

 

[CampStewart]

Electric cooling fans on a 01 2500, are they aftermarket? Are they pushers with a engine driven main fan? Are the cooling fans controlled by the engine ecu or a stand alone controller?

 

[snowblind]

Electric cooling fans on a 01 2500, are they aftermarket? Are they pushers with a engine driven main fan? Are the cooling fans controlled by the engine ecu or a stand alone controller?

Aftermarket dual pullers in place of the engine driven fan. Stand alone controller.