Author Topic: 74 Eldorado Rdiator concern  (Read 214 times)

Offline danjarrett1

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74 Eldorado Rdiator concern
« on: January 03, 2018, 02:54:36 PM »
This past weekend I was faced with a leaking radiator, primarily the area around the petcock was compromised and was beyond my scope to repair in my garage. I pulled the radiator out with the intent of having it repaired and returned to service. Knowing it would be down for a while and unable to move, I chose to call my local Autozone just by chance. Now, before everyone reminds me about cheap aluminum/plastic radiators....I get it! It's maybe not the best long term solution. I bought a radiator, it for just fine and the attach point were on the mark. My concern has to do,with sufficient cooling. I believe the car left Detroit with a 4-core monster brass and steel radiator, will my thin aluminum unit hold up to,summer driving? Anyone have experience with this? Any recommendations for a suitable replacement?
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 Eldorado Rdiator concern
« Reply #1 on: January 03, 2018, 03:10:19 PM »
Experience: yup
Will yours work above 60 degrees outside: nope
Replace your radiator with a. HD 4 row brass/copper unit. Contact US radiator for the right fit.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline danjarrett1

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Re: 74 Eldorado Rdiator concern
« Reply #2 on: January 03, 2018, 03:43:15 PM »
Thanks! I’ll look i to it. I understand that these engines run hot for sure but didn’t think this little radiator was a long term solution
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline danjarrett1

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Re: 74 Eldorado Rdiator concern
« Reply #3 on: January 06, 2018, 11:14:44 PM »
Called US radiator, the sale guy discouraged an aluminum radiator because they don’t have one that would fit without significantly modifying the radiator cradle, suggested the 4-core brass and copper...it’s a direct fit. When my car is back in my hands from the upholstery shop, I’ll order a new radiator...about $700 when all said and done
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline The Tassie Devil(le)

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Re: 74 Eldorado Rdiator concern
« Reply #4 on: January 06, 2018, 11:42:21 PM »
I was going to advise you to try Rock Auto, but after checking what they are selling now, it looks like they only have the Aluminium ones.

I must have got the last Brass/Copper ones they sold a couple of years ago.

If you have an original one, then any good Radiator Shop should be able to replace the core, and there could be one in or near your location.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
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Offline danjarrett1

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Re: 74 Eldorado Rdiator concern
« Reply #5 on: January 07, 2018, 08:40:41 AM »
Unfortunately, I don’t have the original one. It was replaced with a aluminum one as well and it is insufficient
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline The Tassie Devil(le)

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Re: 74 Eldorado Rdiator concern
« Reply #6 on: January 07, 2018, 07:29:48 PM »
That was the trouble I had when I was chasing one.

The Aluminium one was bowed, and leaked like a sieve.

Luckily, Rock Auto had them when I was after one, and as there was no chance of purchasing an original one down here, simply for the end plates, and surrounds, it was a lucky chance that Rock Auto had them.

Now I have spares.

By the way, the "Heavy Duty" one didn't fit the Eldorado mounting frame, so when I use it, I will have to perform some more major surgery to the crossmember.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Offline P. Manoogian

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Re: 74 Eldorado Rdiator concern
« Reply #7 on: January 07, 2018, 08:21:55 PM »
I installed an aluminum one from Rock Auto in a 1974 Eldorado last summer. The car was driven all summer with no problem. I did buy the most expensive one listed on their site.


I also bought one for a 1976 Eldorado for a friend who installed it himself and he has had no problems.
1961 Eldorado - Shell Pearl/Mauve
1959 Coupe DeVille - Vegas Turquoise
2012 CTS Coupe- Crystal Red
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Offline tturley

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Re: 74 Eldorado Rdiator concern
« Reply #8 on: January 07, 2018, 08:30:22 PM »
I had an aluminum radiator custom built for my LaSalle, it is only half as thick but the aluminum disepates the heat way better the the original.
I have used it for two summers in 100 degree temps with no issues.
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Offline danjarrett1

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Re: 74 Eldorado Rdiator concern
« Reply #9 on: January 07, 2018, 11:08:50 PM »
When I get the car back from upholstery for the new top, I’ll probably end up just bitting the bullet and getting the brass and copper 4 core radiator.  I’ve had friends argue the case for aluminum with Audi alley fans, some suggested removing the engine driven fan and replacing it with electric fans. I’m not looking to enter the car in a “concours” judging but I think that the guys at GM in the 70’s did their homework and figured out how much cooling this massive engine really needs, they recommended a large capacity radiator, who am I to second guess them?
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

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Re: 74 Eldorado Rdiator concern
« Reply #10 on: January 08, 2018, 08:59:16 AM »
 ;D  Bingo!!
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold
1950 Jaguar Mark V Saloon resto-mod

Offline TJ Hopland

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Re: 74 Eldorado Rdiator concern
« Reply #11 on: January 08, 2018, 09:29:35 AM »
If you are looking at copper ones be careful if the price seems too good.   Real quality copper ones are expensive.  My recent experience and reading here is showing $500 is reasonable for the sizes most of the older cars use.   That goes for a proper re core or a new one from a quality manufacturer like US Radiator.    If you find one for say $300 it may not actually be copper or if it is its so thin and the fins are spaced out so far its not going to be very efficient.  Likely has less than $100 of material in it and $200 profit for the seller.   US and the good shops should offer you multiple core options.   You can get OE for show quality but you can also get newer more efficient designs if you are not worried about 100% appearance. 

I'm currently running a plastic aluminum one without issues.  It not the model listed for my car, it was listed as Fleetwood limo and 1 ton trucks so it may be a little bigger than the original.   I actually bought it from an old time radiator shop that recommended it to me.   I still have my original if I choose to re core it   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 Eldorado Rdiator concern
« Reply #12 on: January 08, 2018, 10:43:01 AM »
Dan,
Two things I learned "the hard way".  First of all, ANY electric fan you can get behind your radiator will not have anywhere near the airflow capacity that the stock heavy duty fan does. This is from the folks that make the electric fans.
Secondly, the $700.. you said the US Radiator will cost you will be money very well spent.  Eldos need all the radiators they were born with.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 Eldorado Rdiator concern
« Reply #13 on: January 08, 2018, 10:50:58 AM »
TJ,
With all due respects, you live in an area where the summertime high is just about 20 degrees cooler than Dan's neck of the woods.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline The Tassie Devil(le)

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Re: 74 Eldorado Rdiator concern
« Reply #14 on: January 08, 2018, 06:45:23 PM »
Don't forget that one really doesn't need a fan until the road speed drops down below 30 MPH.

The forward motion of the vehicle forces the outside air through the grille, and through the radiator, creating a cooling flow.   

BUT, as vehicle speed increases, to over, say 90 MPH, the splitting of the air in front of the vehicle moves the "splitting" point to further ahead of the vehicle, and less air is going through the radiator, as most of it is going over the top, or underneath.

How do I know?   Well, when you slow down, the temperature gauge starts to drop down, as the air flow re-enters the radiator.   (I know this from experience as when I only had electric cooling fans on my Hot Rod, when I was driving to the other end of the State, the cooling fans didn't come on, until I reached the third set of traffic lights, after driving 120 miles.)

A Motorist went into an Adelaide Dealer, complaining that the AC wasn't operating as it should whilst driving.   The Dealer tested it, and couldn't find anything wrong.   On the third trip back to the dealer, the serviceman questioned the owner as to what he was doing when he encountered the AC problem.   The reply was that when he was cruising at between 100 MPH and 130 MPH, the AC simply wasn't cooling the cabin down.   The Serviceman then tweeked that the fella did most of his driving in the Northern Territory where there was no speed limit on the open road, and it was this loss of air flow that caused the problem.

The Serviceman couldn't do anything about if because they could only "test" the vehicle to the 65 Mph Speed Limit in South Australia, and explained that Holden couldn't anything about it either because the vehicles were designed and built to perform at "normal" speeds.

Bruce.  >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Offline TJ Hopland

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Re: 74 Eldorado Rdiator concern
« Reply #15 on: January 08, 2018, 08:47:30 PM »
Sounds like if you live in the north you better buy a German car that is designed for Autobahn driving.    I could see airflow being a whole different game at different speeds.   Makes you wonder if they do anything special to keep that all in check on 'super cars' that are supposedly designed to go that fast? Even if they don't have AC just keeping the engine cool could be tricky since it takes a lot of power to go that fast.   Maybe they are like the SR71 planes that leaked fuel and barely were flyable below the speed of sound but once you got past that were a sweet ride?
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline danjarrett1

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Re: 74 Eldorado Rdiator concern
« Reply #16 on: January 08, 2018, 09:39:44 PM »
Well, the lesson is airflow and aerodynamics is well received. There certainly is merit to the argument that airflow will affect cooling and that at excessive speeds, airflow becomes diminished and can’t provide sufficient flow through the radiator. I have been flying airplanes as a hobby, and in my business for 35 years, I have flown to everything from a Cessna 150 to a Learjet! I have gone fast in the air but have no immediate plans  to ever take my Eldorado at speeds in excess of 100MPH, I doubt the engineers at GM subjected the 74 Eldorado to the high-speed wind tunnels at Langley to measure airflow the the grill or over the hood... so....I think I’ll just order a 4 core, brass and copper, heavy duty ass radiator and not worry about it any longer.
1974 Cadillac Eldorado convertible
2007 Cadillac Escalade
1980 Cadillac Seville “Bustleback”

Offline The Tassie Devil(le)

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Re: 74 Eldorado Rdiator concern
« Reply #17 on: January 09, 2018, 12:58:09 AM »
The heavy duty radiator that I purchased would only have fitted if there was the adjustments as shown in the picture, or if there was a completely different radiator mounting for the HD radiator.

The chalk-marked area would have to be removed and the pieces replaced 180 Degrees around to fill in the gap.   Similar, but not as drastic alterations to the other side would have been necessary if I had gone ahead with the HD radiator.   But, as I said before, I am saving it for a rainy day.

Pictured also is the out-of-shape Aluminium radiator, plus the serial number which I couldn't identify.

And lastly, the first box came with a hole in the packaging, and this hole transferred into the core, straight through it.   Yes, they sent me a replacement which arrived in good condition.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Offline Glen

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Re: 74 Eldorado Rdiator concern
« Reply #18 on: January 09, 2018, 01:05:28 AM »
The forward motion of the vehicle forces the outside air through the grille, and through the radiator, creating a cooling flow.   

BUT, as vehicle speed increases, to over, say 90 MPH, the splitting of the air in front of the vehicle moves the "splitting" point to further ahead of the vehicle, and less air is going through the radiator, as most of it is going over the top, or underneath.
Bruce.  >:D
I have a different understanding of the air flow.  We know the air that goes in through the grill and radiator comes out under the car and combines with the air that goes under the front bumper.  At normal speeds there is little problem as the excess air exits out from under the car to the side.  As the speed increases the air cannot get out from under the car fast enough and the pressure under the car increases and the air flow through the engine compartment is reduced.   The pressure can get high enough to begin lifting the car. 
Early efforts to reduce this effect was to lower the front end reducing the air flow under the bumper and raising the rear end.  The other fix it to add a spoiler (as opposed to an air foil).  The spoiler causes a reduced pressure behind the car pulling air out from under the rear bumper.   Spoilers under the front bumper are a better fix. 
Again, that is my understanding.   
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