BEST RADIATOR OPTION

The best in my opinion is to recore w/an extra row of tubes. This will allow you to use your fan shroud which will aid in cooling. I would recommend a Hayden heavy duty fan clutch. Have used this combo in my 300 w/ good results even in 90 degree temps.
 
The best in my opinion is to recore w/an extra row of tubes. This will allow you to use your fan shroud which will aid in cooling. I would recommend a Hayden heavy duty fan clutch. Have used this combo in my 300 w/ good results even in 90 degree temps.



Cold Case with fan shroud.
IMG_9415[1].JPG
 
I've been very pleased with my Cold Case MOP 753A as a replacement for the old 18x22" Mopar 2524984 Hi-ALT/AC rated radiator. There was NO shroud for the 2 barrel 383 equipped with a 6 blade rigid 18" fan in combination with that excellent radiator. I replaced it because it leaked in several places and the 110F ambient temperatures here require RELIABLE cooling! The original setup WAS good too! The first year I drove Mathilda through the summer with the original setup, using Bar-S Stop leak to good effect. THEN:

I upgraded from the rigid fan to a DeRale 18" clutch fan after running a 7 blade 20 inch Mopar clutch fan with that old radiator. Both did well. using the Hayden 2747 thermal clutch, but the old radiator would SLOWLY leak. So, by the start of my THIRD summer, 2018, I bought the Cold Case MOP 753A. Despite being 2 inches SHORTER in height, it holds about half a gallon MORE coolant, due to the big 1 1/4" aluminum tubes. It bolted in to the radiator holder just fine, sans drilling, though I had to take a little care with the transmission cooling lines not being clipped by the 18" DeRale fan. I've corresponded with Cold Case about them making an 18"x22" radiator with the 1.5" inlet on the top right with the 1.75" outlet on the bottom left, as they've done for the 16x22" MOP 753A but thus far naught has availed, despite the fact that they make an 18"x22" core, but with the tanks set for 1.5" in/out, in the dead center top and bottom. That won't do for my '66 Newport, except in an emergency.

I also put a 16" electric pusher fan in front of the radiator controlled by a toggle switch. This arrangement has assured Mathilda of running temperatures never exceeding 210 F on even the hottest summer days in Tucson (~115 F ambient, city rush hour traffic) I run a mixture of 3:1 water to ethylene glycol during the summer to prevent rust and raise the boiling point, though the 16 psi radiator cap is my FIRST line in boil prevention.

ONLY this past Saturday, have I put a custom aluminum shroud on this radiator, to reduce reliance on the pusher fan a bit. The shroud incontrovertibly directs more air through the radiator when the engine is turning and the car is moving. I've seen now that engine temperature drops more quickly to the 190 F norm the 180 F thermostat imposes as soon as Mathilda is moving over 20 mph. What a shroud DOESN'T do is improve the cooling when idling in stalled mid-day traffic. THIS is what the PUSHER still has to deal with, and the A-1 fan I bought 3 summers ago still very efficiently cools the engine in those circumstances. HERE is where I'm a bit irate with Cold Case, for their refusal to make an 18x22" radiator for 66 C bodies. I HAVE a Mopar shroud MEANT for that size radiator which would bolt right on the 2524984, but is USELESS for the shorter radiator. This shroud was from a 1965 Imperial.

Get the Cold Case replacement. They make a good drop-in replacement for your car, and even with my small issues, Cold Case has cooled Mathilda over THREE TORRID DESERT SUMMERS, with DAILY URBAN RUSH HOUR DRIVING, for about HALF the current cost of a re-core. The only thing that might serve you better would be an NOS radiator meant for heavy use, but I suspect such now is unobtainium. Be WARY also of other aluminum radiators, which are made of unreliable chineseum. Some of the "OEM" replacements from shopping mall auto suppliers also consist of this evil, treacherous substance.
 
I've been very pleased with my Cold Case MOP 753A as a replacement for the old 18x22" Mopar 2524984 Hi-ALT/AC rated radiator. There was NO shroud for the 2 barrel 383 equipped with a 6 blade rigid 18" fan in combination with that excellent radiator. I replaced it because it leaked in several places and the 110F ambient temperatures here require RELIABLE cooling! The original setup WAS good too! The first year I drove Mathilda through the summer with the original setup, using Bar-S Stop leak to good effect. THEN:

I upgraded from the rigid fan to a DeRale 18" clutch fan after running a 7 blade 20 inch Mopar clutch fan with that old radiator. Both did well. using the Hayden 2747 thermal clutch, but the old radiator would SLOWLY leak. So, by the start of my THIRD summer, 2018, I bought the Cold Case MOP 753A. Despite being 2 inches SHORTER in height, it holds about half a gallon MORE coolant, due to the big 1 1/4" aluminum tubes. It bolted in to the radiator holder just fine, sans drilling, though I had to take a little care with the transmission cooling lines not being clipped by the 18" DeRale fan. I've corresponded with Cold Case about them making an 18"x22" radiator with the 1.5" inlet on the top right with the 1.75" outlet on the bottom left, as they've done for the 16x22" MOP 753A but thus far naught has availed, despite the fact that they make an 18"x22" core, but with the tanks set for 1.5" in/out, in the dead center top and bottom. That won't do for my '66 Newport, except in an emergency.

I also put a 16" electric pusher fan in front of the radiator controlled by a toggle switch. This arrangement has assured Mathilda of running temperatures never exceeding 210 F on even the hottest summer days in Tucson (~115 F ambient, city rush hour traffic) I run a mixture of 3:1 water to ethylene glycol during the summer to prevent rust and raise the boiling point, though the 16 psi radiator cap is my FIRST line in boil prevention.

ONLY this past Saturday, have I put a custom aluminum shroud on this radiator, to reduce reliance on the pusher fan a bit. The shroud incontrovertibly directs more air through the radiator when the engine is turning and the car is moving. I've seen now that engine temperature drops more quickly to the 190 F norm the 180 F thermostat imposes as soon as Mathilda is moving over 20 mph. What a shroud DOESN'T do is improve the cooling when idling in stalled mid-day traffic. THIS is what the PUSHER still has to deal with, and the A-1 fan I bought 3 summers ago still very efficiently cools the engine in those circumstances. HERE is where I'm a bit irate with Cold Case, for their refusal to make an 18x22" radiator for 66 C bodies. I HAVE a Mopar shroud MEANT for that size radiator which would bolt right on the 2524984, but is USELESS for the shorter radiator. This shroud was from a 1965 Imperial.

Get the Cold Case replacement. They make a good drop-in replacement for your car, and even with my small issues, Cold Case has cooled Mathilda over THREE TORRID DESERT SUMMERS, with DAILY URBAN RUSH HOUR DRIVING, for about HALF the current cost of a re-core. The only thing that might serve you better would be an NOS radiator meant for heavy use, but I suspect such now is unobtainium. Be WARY also of other aluminum radiators, which are made of unreliable chineseum. Some of the "OEM" replacements from shopping mall auto suppliers also consist of this evil, treacherous substance.
Super valuable post... TY for the in depth account!
 
The fact is that the aluminum radiators don’t look stock and to this day I’ve not had any issues with any stock factory radiator Wether re-cored or not and I put lots of miles on my classics. This is just my opinion but I do not like the look of an aluminum radiator especially in an otherwise stock car. I’m glad they’re out there for those that don’t have convenient access to a good radiator shop but that’s it.
 
The fact is that the aluminum radiators don’t look stock and to this day I’ve not had any issues with any stock factory radiator Wether re-cored or not and I put lots of miles on my classics. This is just my opinion but I do not like the look of an aluminum radiator especially in an otherwise stock car. I’m glad they’re out there for those that don’t have convenient access to a good radiator shop but that’s it.

Let's add to that , its been proven aluminum radiators do not cool any better than copper.
 
Let's add to that , its been proven aluminum radiators do not cool any better than copper.
I understand that people say that the metal itself it’s any more efficient but what about the fact that the Cold Case radiators hold more volume or coolant? Doesn’t that mean they will be more efficient and keeping temps down?
 
I understand that people say that the metal itself it’s any more efficient but what about the fact that the Cold Case radiators hold more volume or coolant? Doesn’t that mean they will be more efficient and keeping temps down?

I'm not an engineer. Holding more volume how? Thicker tubes? Wider tanks?

I believe the Chrysler engineers designed them the way they did for a reason. Their capacities are what they are, for a reason. If more capacity was the answer they all would have a 28" radiator with 4 rows.

Air flow, fin restriction, fan type, blade quantity and more all play a part in cooling beside capacity.


Of course, I could be completely in left field in thought but I don't think so.
 
I'm not an engineer. Holding more volume how? Thicker tubes? Wider tanks?

I believe the Chrysler engineers designed them the way they did for a reason. Their capacities are what they are, for a reason. If more capacity was the answer they all would have a 28" radiator with 4 rows.

Air flow, fin restriction, fan type, blade quantity and more all play a part in cooling beside capacity.


Of course, I could be completely in left field in thought but I don't think so.
No you are right on.
 
In radiator performance it's about radiator efficiency. If your OEM rad is free of lime and rust build up it will keep your engine cool. The problem w/ aluminum core radiators is there more susceptible to corrosion and electrolysis than the brass equivalent.
 
In radiator performance it's about radiator efficiency. If your OEM rad is free of lime and rust build up it will keep your engine cool.

x2 for keeping it clean. I just had the original radiator rodded out on Medina, my '71 T-code Monaco, and @71Polara383 tells me that she once again is cooling properly. I'll be driving that car for the first time since the cleaning for several hundred miles this coming weekend at the 2020 CATL, so I'll be able to judge for myself.

There is a (very expensive) OEM alternative, Glen Ray. @saforwardlook has used their services -- see here.

@Trace 300 Hurst has only good things to say about the Spectra Premium CU332. He drive his Hurst in Florida weather with it. To quote him:

"The Spectra and a redo of the entire cooling system -- back flushing the engine, new stat and housing, all new hoses, hidden overflow tank to keep air out of the system, checked for correct pump -- solved the (overheating). Recently I (installed) the correct repro 7-blade and thermal clutch unit (from Tony's) and now I have a quiet, OEM looking 190* system. Love it. Note: I run 16 degrees timing with the dizzy limited to 18 degrees mechanical advance (FBO Mopar Distributor Limiter Plate) and this timing setting also helps with engine heat, gives instant starting, and outstanding low-end power."

I bought a CU332 for Snow White (my '70 N-code Polara 'vert) on the strength of that recommendation and because the CU332 looks almost factory (and because Snow had already lost her original rad at some point in the 30 years when the previous owner had her). When I made the call not to take Snow to Carlisle this year, I lent the still-in-the-box CU332 to Wyatt for Elvira, her T-code sister. Wyatt's experience on the trip from IL to PA and back was that his car ran too hot when outside temps were high but the radiator did fine in cooler climes. I'll see how the SP performs once installed in Snow White, hopefully sometime this month. FWIW, both Elvira's and Snow's engines have been rebuilt.
 
The Big Aluminum Bugaboo arises from using a more active, LESS ELECTRONEGATIVE metal, aluminum than copper, and then NOT GROUNDING THE RADIATOR! Thus, one gets into a wet cell situation where aluminum acts as the anode, contributing its metal to an iron cathode. Since the electronegativity of Al is 1.63, making it exactly 0.2V more positive than iron, Fe at 1.83, the coolant solution than can act as an electrolyte, providing an ionic path, (conductor) and permitting robbery. The BEST WAYS to STOP THAT are: 1.) Use ONLY pure, distilled water and a pure source of non-polar antifreeze like ethylene glycol and 2. Use a GROUNDING STRAP direct from the aluminum radiator to the battery cathode. One can even use NoAlOX dopant at any Cu-Al interface.

The mystical reason Mopar engineers in the Days of Yore used copper tubing for their radiators is that this was ALL THEY HAD TO WORK WITH 50 YRS AGO. As soon as aluminum tubing and welding progressed, by the 1980s, the bean-counters both in the U.S. and abroad all embraced aluminum radiators en masse. Large aluminum tubes provide both greater surface area and volume for cooling and coolant respectively. Likewise, one can use aluminum for cooling fins, while using copper as such has always been cost prohibitive in automotive radiators. I like it for my CPU heat sinks however

Copper IS more CONDUCTIVE than aluminum, and conductivity is both a THERMAL and ELECTRICAL property. THIS has been and remains coppers advantage as a structural cooling medium. With an electronegativity of 1.9 V, it is more negative than iron or aluminum, and with only .07V difference with iron, old time radiators using iron fins could be made with little worry about electrolytic metal loss.

BUT: Copper tubing requires SOLDERING OR BRAZING, and these joints have been and remain likely leak points in Cu tubed radiators. Also, being more dense and softer than aluminum, copper tubes don't scale up in diameter as easily as aluminum.

Finally, copper, being a better conductor than aluminum has greater demand, thus price. For COST EFFECTIVE COOLING, aluminum radiators have been the preferred method now for over 30 years. I advise extreme caution in choosing vendors due to sub-standard asiatic wares flooding the american market, but this rule applies as much to putative OEM replacements made with copper tubing also.
 
I'm not an engineer. Holding more volume how? Thicker tubes? Wider tanks?

I believe the Chrysler engineers designed them the way they did for a reason. Their capacities are what they are, for a reason. If more capacity was the answer they all would have a 28" radiator with 4 rows.

Air flow, fin restriction, fan type, blade quantity and more all play a part in cooling beside capacity.


Of course, I could be completely in left field in thought but I don't think so.

Chrysler had a reputation of over engineering their vehicles back in these days. Particularly drivetrains. Dad was constantly reminded by suppliers that brand X only spec’d this gauge or diameter for the same use. His answer was always, “This is Chrysler”.
 
Chrysler had a reputation of over engineering their vehicles back in these days. Particularly drivetrains. Dad was constantly reminded by suppliers that brand X only spec’d this gauge or diameter for the same use. His answer was always, “This is Chrysler”.

I agree, so why jump to aluminum? I also asked how more volume would help in cooling
 
I agree, so why jump to aluminum? I also asked how more volume would help in cooling

Greater volume of coolant, COMBINED WITH GREATER SURFACE AREA ESPECIALLY, permits more coolant to absorb heat from the source, transport that heat to the cooling surfaces, allow them to radiate it, then return to the heat source at a lower temperature than a lower volume would have, to further cool., Greater volume ALSO means GREATER STABILITY. It takes longer to heat a larger volume up, but once ideal temperature is reached, it also helps RETAIN that ideal temperature throughout the operating environment. This lends itself to greater thermodynamic efficiency, more complete combustion of fuel et cetera, ad infinitum, ad nauseum. These reasons underlie the decision to equip automobiles running air conditioning with larger radiators, such as the 26 inch radiators of yesteryear versus 22 inch ones in the case of Chrysler C bodies and Imperials.

Aluminum proved itself to be superior to copper as the preferred cooling medium for standard radiators nearly 40 years go, ONCE INDUSTRIAL TECHNIQUE PERMITTED MASS PRODUCTION OF ALUMINUM TUBING AND WELDING IT TO ALUMINUM FINS.

So,

1. Aluminum permits greater volume of coolant in the same surface area of automotive surface. Greater tube volume also allows greater tube surface area, to which more cooling fins can be attached, permitting further radiating surface area to be cooled by forced air convection.

2. Aluminum has a lower mass density than copper or iron, permitting either greater size for the same weight, or less weight for the same size. The first, again, permits greater cooling.

3. Aluminum is stronger than copper, and best of all, the entire radiator now can be made of ONE element, aluminum, not 3 or four, such as copper + lead + tin + iron. This permits a stronger, more contiguous product to be made AND allows far greater ease in RECYCLING a spent unit.

4. Aluminum leaks less, due to less corrosion, so long as electrolytic safeguards such as bonding jumpers and proper coolant chemistry are maintained. Soldered joints are much more failure prone electrically, chemically and mechanically than welded aluminum. This problem LONG has been known by folk ranging from automotive engineers to moonshiners and BATF staff.

5. Aluminum costs less than copper. MUCH less, as in $1775/ton vs. $6758/ton. This translates into considerably greater expense for a copper radiator core, as has been readily observable over the past 4 yrs and more. This trend isn't likely to reverse, any more than coal is apt to become a cleaner fuel than refined petrol, or whale oil becoming a better transmission fluid than synthetic esters.
 
Greater volume of coolant, COMBINED WITH GREATER SURFACE AREA ESPECIALLY, permits more coolant to absorb heat from the source, transport that heat to the cooling surfaces, allow them to radiate it, then return to the heat source at a lower temperature than a lower volume would have, to further cool., Greater volume ALSO means GREATER STABILITY. It takes longer to heat a larger volume up, but once ideal temperature is reached, it also helps RETAIN that ideal temperature throughout the operating environment. This lends itself to greater thermodynamic efficiency, more complete combustion of fuel et cetera, ad infinitum, ad nauseum. These reasons underlie the decision to equip automobiles running air conditioning with larger radiators, such as the 26 inch radiators of yesteryear versus 22 inch ones in the case of Chrysler C bodies and Imperials.

Aluminum proved itself to be superior to copper as the preferred cooling medium for standard radiators nearly 40 years go, ONCE INDUSTRIAL TECHNIQUE PERMITTED MASS PRODUCTION OF ALUMINUM TUBING AND WELDING IT TO ALUMINUM FINS.

So,

1. Aluminum permits greater volume of coolant in the same surface area of automotive surface. Greater tube volume also allows greater tube surface area, to which more cooling fins can be attached, permitting further radiating surface area to be cooled by forced air convection.

2. Aluminum has a lower mass density than copper or iron, permitting either greater size for the same weight, or less weight for the same size. The first, again, permits greater cooling.

3. Aluminum is stronger than copper, and best of all, the entire radiator now can be made of ONE element, aluminum, not 3 or four, such as copper + lead + tin + iron. This permits a stronger, more contiguous product to be made AND allows far greater ease in RECYCLING a spent unit.

4. Aluminum leaks less, due to less corrosion, so long as electrolytic safeguards such as bonding jumpers and proper coolant chemistry are maintained. Soldered joints are much more failure prone electrically, chemically and mechanically than welded aluminum. This problem LONG has been known by folk ranging from automotive engineers to moonshiners and BATF staff.

5. Aluminum costs less than copper. MUCH less, as in $1775/ton vs. $6758/ton. This translates into considerably greater expense for a copper radiator core, as has been readily observable over the past 4 yrs and more. This trend isn't likely to reverse, any more than coal is apt to become a cleaner fuel than refined petrol, or whale oil becoming a better transmission fluid than synthetic esters.

Again...


Air flow, fin restriction, fan type, blade quantity and more all play a part in cooling beside capacity.
 
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