Radiator Recommendations?

[Rumpity rumpity rump....]

I bought and installed the DeWitts alum. radiator for my built big block, and the electric twin fans rarely come on . It is a high quality product and a totally exact replacement. There may be other good ones out there, but i know for sure now, that DeWitts radiator puts out a superior product.

 

[mrvette]

DeWitts make a decent enough product, but cheaper are available without loss of quality or capacity....but apparently they may not fit as well for a actual plug in/work system...so YMMV....

I do know that the Dual Spal fans cure most ANY overheating problem even with a marginal radiator capacity...I get away with a '~89 F body rad in my '72 and it's only single 1.125 core with plastic tanks...stock GM type....
for a 350 engine....

now the way I mount MY spals is a whole lot differant than most...MY install takes the fans about 2" to the rear of the core, and so are shrouded to the entire core...side of tank to tank and top/bottom and the front with a/c is sealed off so to get max highway speed airflow....no overheating under any conditions and that includes my off freeway onto city street that have to be 140f on the pavements....
I have a <400 hp small block and auto with a/c and tranny cooler in there...and a extra cooler down lo, plus a air cleaner assy in there...
BUT a open grill, NO front tag, but no spoiler either....

 

[A1Avette79]

If you do determine that it's the radiator and that it's beyond repair, replace it with an item identical to the type installed by the factory. The best manufacturer/vendor is DeWitts. Everything else is a second rate substitute that may/may not do the job.

Does DeWitts make an aluminum, stacked plate radiator for a '79, auto, with a/c?

 

[terry82]

i would make shure that the radiator is clean on the out side and the inside .if it still does not cool well i would take it out and see if it is the problem .if it is most will tell you to go to all the fancy name brand places and i am shure that they are correct but,,,,,,i went down to my local auto zone and ordered a radiator from them that was a perfect replacement that dropped right in.it was half the cost of others and has worked fine .its worth checking ,please no flames it worked for me .

 

[6880 Mike]

Just a quick follow-up question or two:

(1) why does it matter if the lower plastic front lip spoiler is attached correctly? Is it so that it forces more air up and into the radiator area? (mine personally is half coming off the bumper, I think I should get that fixed then if that's the case).

(2) Radiator sealing - making sure air flows through the rad rather than over/around.
I've just removed the plastic ductwork to the air cleaner from my '79, and I read that it's important to plug that gap between rad and hood that now exists. How is it best to do this? Is there a specific aftermarket part, or just some thick caulking strip???

Thanks in advance...
~Dan

PM sent.

 

[Vettehead Mikey]

Does DeWitts make an aluminum, stacked plate radiator for a '79, auto, with a/c?

I'm not sure why you'd want one since the (much cheaper) OEM copper/brass unit does an excellent job- plus the need to integrate a pressurized expansion tank, but call Tom and ask.

 

[Bob Heine]

To that point, I bought a very nice aluminum radiator from a vendor on ebay at a very reasonable price. Hib is right- DeWitts isn't the only show in town.

I'm listing the address of the manufacturer to illustrate the point that DeWitts isn't the only manufacturer. Northern Factory, Inc :: Your Source for...

The vendor I used for <$400- UNIVERSAL PARTS INC items - Get great deals on CUSTOM SHROUD ELECTRIC FAN, CHEVY CAMARO CHEVELLE items on eBay Stores!

I've been very happy with my radiator from them. It fits great with only a minimal modification to the stock shroud. I had to notch the shroud around the upper hose provision a little less than a quarter of an inch.

I've added some pictures so that y'all can see how it looks and fits.

That's a fine solution for a small block but the original poster has a big block. Modifying it to work is far more than "minimal modification." There is no cap on a big block radiator, just a 3/8" curved nipple to connect the radiator to the separate tank located under the passenger fender (just barely high enough for the big block cooling system.

Radiator Recommendations
If the radiator turns out to be the problem, you have two initial choices: 1) repair, and 2) replace.

Repair
If you choose to repair the radiator that's in the car, you have two more choices:
A) Take it to a reliable shop. By reliable, I mean one that won't cut your shroud in half to make radiator removal faster without calling you first. This will probably be a $500-$1,000 option, maybe more.
B) Do some of it yourself. If you remove the radiator yourself and take it to a radiator shop to be re-cored, you're going to spend at least $100 -- more likely $200. If you break the shroud removing the radiator, you're looking at $300 for a new shroud and you're probably going to find a rotted-out radiator support (another $400 or several hours fixing the rust and/or patching the broken shroud back together). You may end up choosing not to fix the shroud and just install dual electric fans.

Replace
If you decide to replace the radiator, you have three choices:
A) Exact fit brass (original replacement). The brass radiator for a 72 big block runs about $400 plus shipping. If the problem was a corroded and clogged core, this will fix that problem, You still have the do-it-yourself or take it to someone choice, which significantly affects the price.
B) Exact fit aluminum. Not sure of all the suppliers but a DeWitts runs $500 (OK, $495) plus shipping.
C) Replacement radiator. Your radiator core is 27.5 x 18 with driver side top 1-5/8" inlet and passenger side lower 1-3/4" outlet. You can try to adapt a generic radiator with those characteristics but the bends on the original radiator inlet and outlet are tough enough to connect. I wouldn't sign up for the extra effort even though I'm really really frugal.

I've been messing with my 72 big block automatic air car. The radiator was re-cored three decades ago when an engine mount broke (taking out the fan, radiator and shroud). Installed electric fans and even had a new shroud made to fit them. Radiator was flushed and a new petcock soldered on last year. It works but doesn't instill any confidence I can drive the car worry-free. I finally broke down and ordered the DeWitts radiator. Beyond the price, which I found was more reasonable than most, I wanted some extra features on mine. I am putting dual Spal fans and controller so I wanted a bung for the temperature sensor installed at the top of the driver side tank. I also wanted a -6AN bung installed at the top of the passenger side tank, in place of the curved nipple, so I could connect the radiator to the remote tank with a more reliable braided stainless line. Not sure about the other vendors but DeWitts included these changes at no extra charge.

 

[Bob Heine]

I'm not sure why you'd want one since the (much cheaper) OEM copper/brass unit does an excellent job- plus the need to integrate a pressurized expansion tank, but call Tom and ask.

Not sure I understand what a "stacked plate" radiator is (I've seen oil coolers described that way) but DeWitts does indeed sell a Direct Fit aluminum radiator for a 79 automatic (Model A77A). Brass replacement radiators can be had for $175 (Rock Auto) or $299 - $399 (Corvette Central). The DeWitts runs $495 so the brass unit is either much cheaper (about 1/3 the price) or somewhat cheaper (25% less) depending on your choice of supplier.

Usual reason for wanting an aluminum radiator is weight. Other reason is efficiency. The DeWitts Direct Fit for a 79 is the same tank configuration as original so there is no need to integrate a pressurized expansion tank. The pressurized expansion tank is only needed if you are swapping a big block into your 79. Here's the DeWitts for a 79 automatic (air conditioning doesn't affect the radiator design):
DeWitts - Product Detail

 

[Vettehead Mikey]

The pressurized expansion tank is only needed if you are swapping a big block into your 79.

Say what? :confused

 

[Bob Heine]

Say what? :confused

Vettehead Mikey,

Apologies if I wasn't clear. In your post you wrote "plus the need to integrate a pressurized expansion tank." I assumed you were referring to the tanks used on 68-72 Vettes.
I thought these expansion tanks were only used on C3s from 68-72...

And these expansion tanks were only used on 69-72 big block A/C cars.

They started putting the pressure caps on the passenger side radiator tank in 73 and added a non-pressurized coolant recovery system. If you put an aluminum radiator into a 79 Vette you don't need to change anything but the radiator, as far as I knew. Even the 73-74 big blocks came without the the expansion tanks so I was mistaken about needing one on a conversion. Sorry for the confusion.

 

[Vettehead Mikey]

Bob,

Not all Corvettes prior to 1973 had an external expansion tank- those equipped with a conventional copper/brass rad had an integrated cap and side tanks. As such had no need for an external tank to accommodate coolant expansion.

'73 and up saw the introduction of non-pressurized coolant recovery tanks and the discontinuation of expansion tanks, both internal and external.

 

[BankOfHell]

External fins of radiator get clogged over time. Stuff you can't see unless you remove the radiator and hit the fins with compressed air from the back. Watch out, you'll get dirty doing this.

A fast way to check if it's clogged is to feel the direction of the airflow coming from the radiator fan. If it goes straight back toward the engine, it's not clogged. If it goes off toward the sides toward the wheels, it's clogged.

 

[TimAT]

I'm a bit late to this party, but my 69 has an "over the GM parts counter" L-88 radiator and a slightly modified fan shroud to fit. At highway speeds, the temp would crawl up to "unhappy". I removed the front license plate and bracket looking for the cure. Found it. It'll run up to 200* at 70MPH-- 4000 RPM with the 4:11 gears. All the seals around the radiator and over the core support are intact.