I’m a Phoenix resident so I’m getting ready for the summer heat. I replaced the stock Radiator in my 68 with an 24" aluminum performance unit. I want to remove the stock fan and install a dual electric fan setup.
Has anyone on here done this and what would you say is the best way to setup the fan switches? I like the idea of having a temp sensor kicking them on but also running a manual switch to the cab so i can control it would be a nice option as well.
Would love to hear how anyone else has done it and what they think.
The best cooling system is to use the big block fan and thermal clutch with a shroud. You won’t have to replace the alternator. I like in cave Creek and most of the AZ Cougar owners run the same set up.
I opted for the electric fan route myself and very happy with how it turned out and has been running. Full disclosure I have not fully tested it in the middle of the AZ summer heat yet but I do not expect any issues based on the radiator and fan capacity. I had originally wanted to run the factory style big block fan clutch setup like Bill mentioned but after some research I chose electric fans instead. Cost is probably about the same even considering the alternator upgrade but depending on your overall goals with your car you may need an alternator anyway. Another thing I like with electric fans is freeing up some space in the engine bay along with freeing up parasitic drag from the mechanical fan however debatable. (another rabbit hole to go down)
If you choose electric fans I highly suggest running a PWM module to control them. Not only do they allow a 0-100% operation based on temp they allow you to adjust the on off temp, keep the noise down since they are not running at 100% all the time, have a manual override for an interior switch if desired and provisions for AC temp controls. They also function as the relays which are solid state vs mechanical so they will not wear like a conventional relay would. If for some reason the module fails they failsafe to full 100% operation to prevent an overheat condition. I used conventional relays at first and while it worked I was unhappy with the temp sensor control or lack there of and overall wiring clutter. Using this PWM made all the difference in the install in my opinion. Fans are only run as fast as needed to keep desired temp thus being much quieter when operating.
These fans fit perfect on the 24" radiator and have a shroud that allows pass through air at cruise
ditched the mechanical relays as they only allowed for 100% fan operation and not a duty cycle like the PWM gives you
PWM relay setup offers seamless control over the fans along with fine tune adjustments to temperature.
I go into more detail and pictures of the install here
https://cccforum.discoursehosting.net/t/cat-napping-through-winter/207/1
If you are going electric DieselD has the right solution. It fully addresses the issues and if there is sufficient air flow it should work very well this summer. In particular if you have AC this is what you want.
I also use dual electric fans using the PWM controller from AutoCool guy and Derale fans and shroud along with a DeWitts 24” aluminum radiator. I’m in MI so I don’t see your level of summer temps but the system has kept my car temps under control for a few years now.
I did increase alternator output but I also converted to EFI and the required electric fuel pump so an alternator change was in order for my car.
I use a dual electric fan setup with temp switch controlling a relay. I also have a manual override on the dash. Alum rad and this is with a modified 460 in a 68 Cat. No problems at all. I did go to a 100Amp 1 wire alt but only because most early Ford ones are to weak even back then. 60Amp isn’t enough with todays stuff on a car. Even the electronic ignition system want more.
I also use the same setup on a 66 Stang I have with a 331 Stroker.
I run the same Dual Fans that DieselD does, but I got into the relays and swapped it around so that the passenger side fan turns on at a temp that I can set with the knob, and the other fan is manual switch below my AC controls. It’s not gotten too hot yet here in Southern California but with my 24" 3 Core aluminum radiator, and the dual fans, it’s worked pretty well. I was worried since I have a 351C that’s bored .030 over and just about everyone mentioned how hot it can get, but that cooling along with the restrictor plate below the thermostat works pretty well so far.
I didn’t use any external controller, just the stuff that came with the fan, but I’m sure for the cleanest setup and peace of mind it would be the route to go.
My 68 had a twin fan set-up installed when I bought it. At the time the fans were activated via a toggle switch. I used the kit linked below to sort it out. Has the harness, relay, circuit breaker and temp sender. Only took about 45 minutes to install and test. Now fan cycles on and off as temp goes up and down.
https://www.amazon.com/gp/product/B015R9AVMA/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
CWatson
