Re: Why electric fans?
Well, as an ex: drag racer, hot rodder, mad scientist engine swapper; I love electric fans. They are a great tool. Like any other tool they cannot be used all the time, but they are very beneficial when you need 'em.
For one thing it takes less than 1/5 of 1 HP to generate enough electricity to spin the average electric fan. Engine driven fans can suck up anywhere from 4-10 hp. Swapping to an electric fan can sometimes mean maybe .03-.05 seconds off 1/4 mile time in your streeet macine/weekend racer. That may not mean s#it in a Jeep, but it does equate out in another area as well... fuel economy. That is the primary reason for clutch fans and electric fans being installed by manufacturers. Electric fans help the manufacturers meet federal CAFE standards. Swapping to an electric may be worth 1 MPG or more on the highway, less around town.
However, the main reason that I personally like electrics is their versatility and their ability to be squeezed into small spaces. I have performed or assisted in way more than my share of engine swaps. Among others, I have built a 440 six pack 1/2 ton '82 Dodge Ram; a 427 tunnel rammed '78 Camaro; a 307 Chevy powered, rear wheel drive VW Scirocco; and a tube framed, front engine, rear wheel drive 454 VW bug.
Ever try to stick a V-8 into an early CJ? Sure, starting in '72 they made it easy but that 3'' makes a huge difference. An electric fan makes it possible.
Electric fans may not be needed in every application, but they are worth their weight in gold when you need 'em.
Hell, my Cummins powered M-715 would not be possible (well OK, not as "easy") without an electric pusher in front of the radiator. Without the engine driven fan the Cummins fit perfectly, otherwise I would have had to modify the firewall to get the room. I overkilled it and put 2 1800 CFM pancake pushers up front, and it hasn't seen the other side of 180*.
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