Can anyone recommend a good radiator and fan/fan motor for a 1970 cougar Xr7 daily driver with a 351c? If possible ones that will not break the bank but good quality. Thanks for all recommendations
Here is a great video about cooling system upgrades:
Radiator and Fan Upgrade - Small Block Cougar / Mustang 1967-70 - YouTube
And for the Cleveland, you need the correct thermostat too. Here is some discussion on that:
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I went with a Griffin combo in my 73 , very happy with it especially in south Florida. Good heads up on the t-stat, make sure you have the brass washer in the block. Doubt you can get them at the local parts store
Good quality radiators and fans are usually the more expensive ones. No idea what your budget is but that will drive your selection.
I use a DeWitt aluminum 24” wide radiator (made in MI) and a dual electric fan/shroud from Derale on my swapped 1969 Cleveland. I upgraded the balance of the cooling system at that time as well-water pump, correct Cleveland thermostat, hoses (w/lower hose spring), radiator cap, recirculating reservoir, and PWM fan motor controller.
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Electric fans that have adequate CFM for cooling at idle need a lot of power. That typically means that you will also need to go with a bigger more powerful alternator. Ford 3G alternators make a good swap. Aluminum is cheaper than brass / copper but not quite as good. The difference is not a deal breaker. The fan and shroud are very important if you are doing a lot of low speed driving. Remember, at highway speeds the fans do essentially nothing.
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You’re gonna find varying advice depending on source (who said it and what they’re selling).
I’m also going with the WCCC advice, repop shroud, 7 blade BB clutch fan, 24” radiator. Will try the ACP aluminum 3R version (hey, they went on discount so I bought 2).
Each material has advantages and disadvantages. Brass conducts heat faster. Aluminum forms a more stable oxide and has better strength to weight ratio.
For overall heat transfer, the outside convective coefficient governs overall heat transfer rate. The other two resistances - conduction through the metal, and convection from the liquid - are lower. So I think regardless of metallurgy, achieving max airflow through the finned radiator area is a key goal.
Griffin says alu gives an advantage here by enabling larger water flow tubes and fewer rows. I’d like to see the calcs and test bench data, as this also means a loss in heat transfer area.
It’s probably accurate to say that the originals are brass because copper was a lot cheaper in the 1960s. Not sure many new vehicles come with brass, for cost reasons. SS316 would probably also work great, price be damned.
My 69 XR 7 with a 351W stays cool with this combination: 24” brass radiator with a reproduction shroud, flex fan from a 78 Thunderbird. No overheating issues.
Akso, I have the transmission cooler totally divorced from the radiator. I have a trans cooler from a Probe connected to the transmission lines.
Some of the import cores have too high of a fin count per inch..
Getting the air thru the core can be an an issue on our cars
Look what Cougar did on big block ac cars to force the air thru the core
It works
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+1 yessir! Or the people who say… oh i’m gonna get a 4 core, that’ll cool even better. and then on top of that if you have A/C, you have the condenser in front of the air flow before even getting to the radiator. (the aftermarket A/C kits cover the entire radiator face) so… major restricted airflow, then forget staying cool at hot days slow and idling… you can’t even stay cool on the highway anymore.
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Hello. Can you share more info on electric fan setup. I have 70Cougar 351
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I used one of the Derale Powerpack dual fan/shroud systems. It has two 11” electric fans with beefy motors and an aluminum box shroud with rubber flaps to allow for air flow through the radiator at higher speeds. As noted here previously, as these are electric fans you need to consider power requirements. I intended to use electric fans along with EFI so I had already installed a more powerful alternator capable of supplying power to the fans, the EFI system, the electric fuel pump and extra capacity for future changes.
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Is this the kit you chose? Derale Cooling High Output Dual 11" Electric RAD Fan Aluminum Shroud Kit 16833 | eBay
I can’t recall the exact part number at the moment. I installed it in 2017 I believe. If not that exact one, one very much like that one.
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It is very capable of removing heat from the radiator. Switching the fans on to full speed I can see a 25-30f drop in coolant temp (digital gauge, measured by EFI temp sensor). I run them with a PWM speed controller with soft start and post shut down run timer feature.
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Thanks that sounds great, and my new alternator is custom built internally for 100amp max output too.
Spall dual 2700cfm fans in the spal plastic shroud with 8 flap doors. 67 gt with 390 a/c. Had to add a second idler to get ac belt to clear drivers side fan motor
Controlled with PWM system that drove me crazy unil i ran a 8ga wire from the bat neg post to the pwm ground. Chassis ground would no cut it. 3g alternator
At 120 deg outside , car would idle on the tstat all day with the ac on
I am using an Aluminum radiator from Champion Radiator in Lake Elsinore, California. They have a large selection to choose from. I have a ‘67 XR-7 with a 289, and I chose a radiator that was specified for 500hp. Purchase price was less than $300, 3 years ago. I have no cooling issues with this radiator and the mechanical fan on the water pump. Please note that I do not hot rod this single family classic.
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