65 Mustang 289 w/A/C Converting Stock Radiator to Aluminum

dvelek

Member
Jun 5, 2019
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Alvin, Texas
Do you'll have any suggestions on a good Aluminum Radiator for my 65 with A/C? Stock radiator I have is just not able to keep up with the A/C I added on recently. Thanks.
 
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rbohm

SN Certified Technician
Apr 12, 2002
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start by buying the radiator from a reputable source, like NPD for instance. also when buying dont get an aluminum one that mimics the stock design in regards to tube width. the stock tubes are something like 1/2" or so where as a proper aluminum radiator should have tubes that are closer to 1 1/4" thick for better heat dissipation. so that aluminum radiator may still only be two rows thick, but it will have the cooling capacity of a copper/brass radiator that is four rows thick.

be aware of fitment issues though, they should be minor though, mostly trying to fit a fan shroud with the thicker rad, and probably using a shorter fan spacer, again due to the thicker rad, unless of course you are going to use an electric fan.

one more thing, make sure the radiator you buy is for the street and not the track. the reason is the fin count per inch. the higher the better for the street, to a point. you need at least 16 fins per inch for best cooling. more and they tend to block airflow, less and there isnt enough to cooling at low speeds.
 

zookeeper

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Aug 25, 2001
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I got mine from here http://www.speedcooling.com/radiators/ and couldn't be happier. It fits perfectly, looks nice and I've sat in traffic on a 100° day and it never got past halfway on my stock gauge even with a stock fan and no shroud. The stocker it replaced was up near "H" anytime the temp outside was over 80°. Plus it was only about $200, try it, you won't be sorry.
 

dvelek

Member
Jun 5, 2019
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Alvin, Texas
Afternoon and appreciate the info and sounds good I am ready for this stang to run cool so I can keep it out on the road more in this Houston heat!
 

zookeeper

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Aug 25, 2001
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Same here. I used to either park my car or only drive it early in the day or late, because I knew if I took out and got stuck in traffic, even for a short time, it would be puking coolant. Not now, cold as ice and since the temps are now reasonable, it starts better when hot.
 

Navyflyer72

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Mar 24, 2018
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Just ordered from there zookeeper, I’ll definitely be posting my experience with photos as soon as she is installed, got a decent overheating issue going on in my ‘65 with a 91-96 302 in her.
 

dvelek

Member
Jun 5, 2019
33
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68
Alvin, Texas
Went with the Dewitt since I had a lot good feedback on their product and they were very helpful over the phone to make sure I got the right fit so I'll keep you'll posted once I get it installed.
 

zookeeper

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Aug 25, 2001
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If I can offer a little advice, here's some things to look for: mine bolted right in. However, the drain petcock felt closed, but wasn't. As a precaution, I poured some water in first to fill the bottom tank to make sure it was sealing before I poured anti-freeze all over my floor. It wasn't sealing due to a sloppy job during assembly of putting the Teflon tape on. So I disassembled it, cleaned the threads and re-sealed the whole thing. Also, the "wings" of the drain petcock nearly hit the cross-member and should be trimmed 1/8" or so just to make it easier.
 

dvelek

Member
Jun 5, 2019
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68
Alvin, Texas
Evening and just got the radiator installed and still running hot at around 225. Now I'm thinking I need to replace the water pump to see if that will help. You'll have any suggestions on what to go with on a good water pump ? Thermostat seems to be working fine but might replace it anyhow. Also I'm thinking we need to do a flush on the block to see if there is some sort of blockage there. Any suggestions on what the process is for doing this? Thanks.
 

zookeeper

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Aug 25, 2001
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I replaced my water pump just as a precaution, but I doubt that's your problem. Here's how 'd approach it: First, verify your gauge is accurate. If it's not puking coolant out at shutoff, it may not be as hot as you think. Buy a laser heat gun. Harbor Freight
https://www.harborfreight.com/121-infrared-laser-thermometer-63985.html
has them for cheap and they're accurate. Let your car warm up and take a reading off the upper radiator hose near the thermostat. It should be at or near the same as your gauge. If not, buy a new sending unit or gauge.
Next, check the thermostat. They are cheap and easy to replace and have been known to fail.
I also gotta ask, what was the condition of the coolant you drained before the radiator swap? If it was horribly rusty, has chunks in it, or anything else, then yeah, that's going to need a flush.
Are you using electric fans? If so, don't make the common mistake of putting them in front of the radiator, that actually blocks airflow.
Mine has no shroud, a stock, non-clutch, non-flex fan and I've had the car idling in 100+ degree traffic and the needles not been over halfway on the stock gauge.
Also, make sure your timing and carb are tuned correctly. Get the timing wrong and all the radiator in the world won't keep it cool under load.
 

dvelek

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Jun 5, 2019
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Alvin, Texas
Appreciate the response zookeeper and I agree I'm feeling the same way on the water pump. We did shoot it and it is off a little on the temp but only about 5 degrees. We are going to replace the thermostat tonight . The coolant was not real bad but did a little sludge mixed in . Yes on the electric fan and it is mounted behind the radiator. The carb is in pretty bad shape and needs to be replaced . I have to keep the idling turned up to keep it from stalling especially since I added a/c. Thanks again zookeeper.
 

dvelek

Member
Jun 5, 2019
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Alvin, Texas
Well after we removed the housing there was no thermostat in place so it's been running without one. Installing one to see if that might solve the problem.
 

zookeeper

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Aug 25, 2001
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Good find! Yeah if there's no thermostat, the coolant doesn't have the needed restriction to slow down long enough in the radiator to be cooled properly. Bet that fixes your problem.
 

dvelek

Member
Jun 5, 2019
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68
Alvin, Texas
Unfortunately it did not fix the problem. Still running 225 -230. I'm afraid we have an obstruction in the block that's causing it unless you'll have any other ideas on what is causing the overheating. Also looking for ideas for the best way to flush this area.
 

rbohm

SN Certified Technician
Apr 12, 2002
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ok first thing to do now is to flush the cooling system, there are kits and chemicals to do the job.

if that doesnt help, then start looking at airflow through the engine compartment. if you have headers installed, they will tend to bloc air exiting the engine compartment, and increase heat retention. one thing you an try is to remove the hood and drive around like that. if the temps go down, then you definitely have an airflow restriction, or other air circulation issue.

is there a fan shroud in place? is the fan properly centered on the radiator? did you install a shelby style valance panel that opens up the area where the license plate would go? if so did you also install a chin spoiler? if not that might be part of the problem.
 

dvelek

Member
Jun 5, 2019
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Alvin, Texas
Removed the drain plugs on the block but coolant flowed freely with no particles that we saw but we will do the chemical flush out tomorrow evening and run her for a few hours each day for the next 3 days. We installed the old radiator to risk any damage to the new one during the process. Fan shroud is in place and centered. Spoiler in place so hope this process solves the problem.