Allan R

I'm about to tackle the cooling system on my 72 Cutlass S. In the past I've had some issues with the temp running hotter than normal which usually results in the rad puking all over the ground after the car's shut off.

My plan is to change the rad from a 2 core (OEM production) to a 3 core. Also installing fan shroud and seals, fan clutch and 6 blade fan, HD water pump and pulley.

Here's my dilemma right now. This car was never AC, and I can't find any examples in the CSM or Assembly Manual for non AC cars with HD cooling. The diameter of the new pulley is smaller than the stock pulley and I'll need a new belt. Does anyone know where to find that? Appreciate any input you can give.

And for the record, I don't want to install electric fans behind the rad. I want the car to look as period correct as possible.

Dave26

For what it's worth....my 72 Supreme 350-auto....would do the same thing, after a good flush, I put a high pressure cap (14-18#) and an overflow tank. OEM style radiator.....no problems.

70sgeek

a good aluminum radiator, performance thermostat and new thermal fan clutch will probably solve your problem - I'm in Central FL running 180 all day long with my '72 (factory a/c 350). I also run a Milodon HV aluminum water pump.

Auto City Classic - 68-72 A-body 2-core, 1-1/8" tubes, factory tank style appearance. you can paint it black if you want total factory look. They sell it in kit form w/fan and shroud or by itself if you plan to install oem parts.


http://www.autocityclassic.com/cheve...inum-radiator/

MDchanic

Allan, the Parts Manual shows the fan belt configurations for each permutation, including the part numbers for the belts and the pulleys. Just cross reference the GM part number to Gates or whoever and you should be all set.

You can confirm this in the Parts Manual, but, in general, the HD cooling cars had the same equipment as the A/C cars, so just treat it as though it's got A/C.

My personal recommendation: A four-row radiator is likely to cost the same, or even less, than a three-row, so you might as well just go for a four-row.

- Eric

Allan R

Thanks Dave. I should have mentioned that I also have an OEM overflow tank for the rad. It should help with the spillage. Using a stock radiator cap.

Thanks for the suggestion. I should have mentioned that I already have the 3 core rad. It allows me to use the stock rad mounts, although I did have to replace the rad top plate to allow for the fan shroud mount. I run a 195* stat.

Allan R

Eric,
Yes I saw all the combos in the assembly manual. What I don't know is whether the distance from alternator to the pulley is the same for AC cars and non AC cars. As you likely remember the AC alternator position is on the LS because of the AC compressor. It might work out fine with the existing belt, but I'm just trying to anticipate possible belt changes. The non AC water pump and pulley are noticeably different than HD cooling.

joe_padavano

The Olds belt drive uses three belt "tracks", each a specific distance from the front cover. The alternator uses the rearmost track in both A/C and non-A/C applications. The belt and pulley diagrams in prior years show this, but the 1972 diagrams do not. The trick is that you need to use the specific fan pulley that matched the water pump length. Note that non-A/C cars with HD cooling used the three groove fan and crank pulleys, despite only having two belts.

Allan R

Thanks Joe. I have several pulleys. The one I'm thinking will be right was taken from a 71 CS with 350 HD cooling. I also know about the 3 different wp snout lengths, so that's also a factor.

cdrod

Allan:
I had overheating issues with my '71 CS running the AC in stop-n-go traffic in the Texas heat. I installed a 4-row radiator, but that didn't solve my problem, so I installed a FlowKooler #1775 high-volume water pump and a Robert-shaw high-flow thermostat and my problems were solved. I suspect the HV water pump & thermostat made the biggest difference. The Flow-kooler #1775 is the long nose W/P for AC applications.

Rodney

midnightleadfoot

The flowkooler has a closed impeller that is the only difference , they used to sell the impeller separate .
Many coolant problems is the coolant moving to fast in the system..
The closed impeller helps move the coolant better than the oem impeller . not faster but with more umpth..
many times a coolant issue can be the impeller blade spinning on the water-pump shaft, stalling . check for this.. (you'd be shocked how many rebuilt units do this)


Also check the rotation of impeller.. don't blindly trust the rebuilder put the correct one on that part # pump..


Thermostats come in many flavors, but most are down to 2 types standard and high flow.. Then you have the other options like "fail open"
Many times the "high flow" ones allow the coolant to move to fast to pull heat out of the system .


Your 2 core rad. is most likely just fine.. but needs a good cleaning..
There is a reason you find larger core tubes and only 2 cores in newer vehicles.. and not 3-4 cores that only block the airflow through the unit..
The copper/brass can't be made with the larger core tubes and not fail from psi. and the older copper/brass tubes are much smaller..
a new style 2 core has as much if not more surface area as an old 3-4 core..
only reason they are alum is the tube strength . the same layout in copper/brass would cool better. but the tube thickness, and cost of materials would make it $$$.


I know this make the car not look stock, but sealing the grill to core support channeling the air through the rad. makes a huge difference.. this helps the air not go around it at speed but through it..


Ideally a alum 2 core Misted black (not buried in black paint and not gloss paint) and sealed to the core support and shroud. will make a huge difference. the core support to grill ducting will only make that even better even in traffic as it not be sucking in engine heated air from over and under the core support but outside the grills..


For the guys needing stock looking, the rad in the car being re-cored, will fix many ills..
I don't believe in "rodding out" a core as the tubes are already pitted and it will only be a matter of time.. and those pits just give the garbage something to grab hold to.. and start blocking the core again..


The next issue is once the hot air is through the rad. it has to be able to exit from under the hood.. while not moving or in traffic. most don't address this, and then that hot air exit over the core and under it only to be sucked back through the rad. core.. and you watch the temp gauge slowly climb..
That cowl to hood seal.. a few well placed cut outs make a huge difference.. you don't cut it completely out so water runs down the firewall, but it not sealing tight to the hood in 3-4 places 2-3" long each.. huge difference of idling and or slow traffic air flow under the hood..


sorry for the book..

rustyroger

I'm not clear on whether or not you have a shroud right now?.
I'd bet just installing a shroud where there wasn't one before wil make a big difference.

Roger.

Allan R

all input is appreciated, no need to apologize. I need to pull the 2 core anyway so that would be a good time to have it cleaned and pressure tested. It is the radiator the car was born with so it should work. If it needs recore, I'll likely install the 3 core sitting in the wings. I will also be installing all the side seals that were available to help direct air flow. This car never had HD cooling so as Roger suggested that may help a lot by itself. I don't want to cut the cowl lacing. Let's see how the changes affect cooling first. The car isn't a DD so stop/go driving isnt really on its radar, but I do understand your point.

No, the shroud is going to be added. I have all the parts needed to transform the cooling system now, and if the belts fit the new wp, I'll just order new ones from rock auto.

midnightleadfoot

On the cowl.. seal I've use the corgated plastic sheet in a 1-2" strip the whole length
weatherstrip adh. held it to hood paint matched , and seal hit the other side of it, the air flowed through the plastic sheet, This was a chevette with a 472 in it.. it needed any extra cooling I could get it..

Allan R

A Chevette??! I had one in 76. How did you shoehorn 472 in there?? They use those for ice racing up here.

midnightleadfoot

Tons of room, no rad. instead house forced hot water baseboard pipe in the c channel front bumper and behind lower air dam.. it was tight but.. only has to stay cool long enough to get down the return road.


Wish I took more photo's of the heaps I built.. most were not safe at any speed..
.

Allan R

Lol, that's Ralph Naders by line for the corvair. That first Chevette was a nightmare. Grossly underpowered and weakest ventilation system I had ever seen. It was ok in the city, but God help you on the highway. IIRC it would almost do 75 mph floored. I can't imagine what that 472 would be like to stomp on. Isn't that a Cadillac engine? If memory serves I had one in my 78 Coupe de Ville.

midnightleadfoot

yes a caddy 472