Electric fan or not?

Hey Guys, I've read the articles about putting an electric fan in and junking that manual fan. The articles were good but I'm still not really convinced electric is the way to go for some of us.
I had a 70 Mustang with a 302 and installed a big bladed flex fan and never had any trouble with it...of course there was always the safety issues but no problems what so ever even in hot weather.

I have never owned an electric fan or installed one and that sounds easy enough to install but I'm thinking these electric fans can give you more problems even if they cool great. More parts to screw up like the temperature switch or wiring or whatever. The price can get costly as well...how about some here telling me other wise, remember now I've read the tech articles but want to hear more.
I've got a 66 fairlane with factory AC and the 289 engine which will have headers and other mods added later so there will be added heat. Give me some feedback on this mod please.

In the Falcon (similar to your Fairlane):
Radiator - Summit 31 x 19 - $189
Fans - LT1 Camaro - Free, required one motor at $45
Mounting fabricated. Keeps 500HP 351Cat 200F with 100F+ ambient air temps.
Works fine in traffic in the heat, moves a lot of air, uses OEM parts available at any Auto Zone or some such. They even sell the connectors. Requires good clearance to the engine - about 4 1/2".

Items to keep in mind - most parts store fans do not move enough air. You need a real 2500 CFM+ to make it work. Most part store fans are rated at zero back pressure. Refer to specs at Flex-a-lite for details. Do not use a radiator with a tight fin concentration and/or many cores. Electrics lose a tremendous amount of efficiency with a restriction like that. The Summit radiators use 8 fins per inch, more or less. Be sure to use as much of the surface area of the core as possible. Make or buy a shroud that covers the whole core and mount the fan(s) to that. Choose core surface area over core density. This usually points you to an aluminum dual 1" core unit vs a typical copper/brass unit. Run the motor hot - 195F t-stat is recommended. Hot water give a greater temp differential with the air and increases heat exchange and efficiency.

It's my understanding that electric fan will reduce the Horsepower drain caused by the manual fan. Don't know how much hp drain is involved.. likely to be dependant on many things.

Interestingly, I installed a Maradyne fan, identified in the tech article. Ran great Sunday and Monday.. Drove to work today and it didn't kick on. Turns out it blew the 30 Amp fuse. Not sure why yet (drove it home and parked it).

It was easy to wire up, and I think it will be beneficial, once I figure out why this thing popped the fuse. I was running slightly warm with the manual fan I had, which is why I switched.

I also understand that if you run AC, you have to have the electric fan run all the time, to get air flowing through the condenser, otherwise apparantly the AC will overpressure.

Just my thoughts based on what I've read thus far.

Mike

I Run a electric fan on my 66 with a 351 headers etc. No problems at all I run it off a tempature switch so it comes on automatically.Plus I have a over ride switch in the car so I can just switch it on. My fan is wired through a relay which is a must for the big draw of a electic fan.Most new cars run eletric fans as well
for milage etc.Im sure there is pros and cons of each. For instance and electric fan should put less force on your water pump bearings and if you get sucked into a eletric fan Im sure it would stop unlike a mechanical fan.Bottom line I think it is a matter of preferance.

DO YOU HAVE A wiring diagram with the relay and therastat switch included ??Thanks Dave

Ill have a look I installed it 5 years ago.

I love my big electric fan, all the tests I saw said that it will save you 5-20 HP depending on the mechanical fan type.

It will let the engine accelerate faster, but in the long run does not save HP. The electricity to run the fan still comes from the battery and the battery uses the engine to charge it back up.

As far as cooling, most of them do a great job at it, but a flex fan with a shroud will cool the engine better, if the cooling capactity of the radiator is marginal.

Im not sure I follow you... The battery uses the engine to charge itself back up, regardless if there is an electrical fan or not. If your battery/charging system can accomodate the additional electrical draw, how does that translate into horsepower drain (ie not saving HP)? Especially if the fan is not running constantly. If the drain on the battery lessens because the fans not running, does the HP loss go away?

Not saying you're wrong.. I just don't understand.

Mike

Energy is not free. If it takes 22 amps to power an electric fan, it takes 22 amps of power from the generator to charge the battery back up. The engine runs the generator. The more current the generator must create to re-charge the battery, the more HP it needs from the engine to make that power.

With an electric fan, Because your generator is converting mechanical energy, to electrical energy (maybe 5% energy loss in the conversion), then storing it (maybe 1% energy loss in the storage and power regulator process) then converting it back to mechanical energy to run the electric fan (another 5% energy loss) then you have just used 11% energy that you can not recoupe.

Mechanical direct, (standard fan) has it's energy loss too. But it has the ability to run harder then the pure elctric only fan, when the engine makes more RPM's, where the electric fan is a constant draw, and has it's cooling limits. On a High HP motor, sometimes it hits it's limit.

Energy is not created out of thin air. If it was, it would be called a perpetual motion machine.