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"Alcohol and Calculus don't mix. Never drink and derive" !!!

Six cylinder Mustangs can be "performance stang's" also (At least mine is). Do what you want but it worked for me!!
Later,

Doug

One HP = 746 Watts, and a 120 Amp alternator at FULL output produces 120 amps x 14 volts = 1680 Watts. Barely power your wifes hair dryer. That means that it only draws 1680 Watts / 746 = 2.25 HP. (The real killer here is that now you know your wifes super stud hair dryer uses 2.25 HP in electric power! And you wonder why your electric bill is so high)

As we are all aware, engine driven fans consume a lot of power. (Some fans will draw 30+ hp at high rpm) And the amount of power is not linear. The if you double RPM the power that is required for the fan WAY MORE THAN DOUBLES. Where as the electric fan is always at peak output at the same power consumption.

Your killer electric fan, drawing 20 amps, requires only .375 hp. (20 amps * 14 volts = 280 watts, 280 / 746 = .375 hp) Its well documented that some engine driven fans can consume 40+ hp at high rpm.

Now you can get into situations where an electric fan would be hard to package. Like a F350 PowerStroke Dually. That radiator holds over 20 quarts of coolant and a fan to pull air through that core would look like an old attic fan. (To you really young guys think big box fan in the shop)

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SteveW

There are valid reasons for going to an electric fan, but for most folks I think these are few. In temperate climates and under normal usage, even a "flex" replacement offers only minor improvement. And there's no such thing as free horsepower. ;-)

Stock fans are cheap, plentiful, durable....and perhaps a bit quieter than many modern ones. Plus, don't discount their close relationship with OEM shrouds. Typically, you want the fan to intrude no more than one-half within the shroud's opening.
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Mr F

In an older car a high output alternator would be needed. A shroud / duct work to work with the electric, proper wiring and thermostat, all these things may be needed.

An electric can work in any situation, but the engineering has to be there. If Mercedes can use electics fans on a 400+ hp 7 Liter V-12, and considers them reliable enough to put on a $150,000 car then I think the concept is ok.

Hot rodders spends hundreds, if not thousands, of dollars for 5 to 10 hp all the time, this is just one more way to accomplish it. (Ask Alex how much he spends for an extra HP here and there) If you could get 10 extra hp from a motor that only made 120, thats almost 10 percent, and nothing to sneeze at.

If anyone wants to find out what they need to do to improve the operation of their car just look at new factory cars. These guys work their butts off for 1 more hp, 1 lb less, .1 mpg more and so on.

The fact is that an electric motor is much more efficient and reliable than a gas motor, electric fans and water pumps are just some examples. In the near future most factory cars will have electric water pumps, power steering and ac compressors in the near future. One of the things that the factories are doing to support this is changing to a 42 volt electrical system, which you will start seeing in high end cars within a year or two.

Electric Fans are ALWAYS better, unless you overheat. So if you choose an electric fan with the proper CFM you'll ALWAYS be better off, horsepowerwise. Of course dollarwise makes a difference, a good electric fan will cost over $125. A properly wired electric fan will never drain a battery.

I use a Black Magic Universal Electric Fan. It pulls 2800 CFM, and only draws 13 amps. It comes with its own shroud that fits the old Ford square radiator almost exactly. It also comes with a relay and thermostat already mounted to it. The wiring is simple and if the key is off the fan is off too. It comes on automatically when the engine reaches a certain temp, so there is no horsepower lost at all (even through the alternator) until the engine is hot. You can easily hook it up to A/C (so it runs with A/C on) and to a manual switch. This fan costs about $185 though, which is pretty pricey, but there can't be any arguement that a mechanical fan is better performance-wise.

I drive my car daily (except for recently because of engine problems, but its my only car so I'm walking now). I've never had a dead battery.

I first bought a cheap fan for about $85. It worked Ok, but burned out on me. At that point, you could say I hated electric fans. But with a high performance engine you can't expect a cheap fan to hold out. There isn't a fan designed for your engine, and you have to find one that will work yourself. Its not hard. You have to look at CFM and quality and get the best out there. Since you can't use the Black Magic, you'll just have to continue to look at specs. 1200 CFM does not sound like much. I'd try to get a bigger fan that flows over 1500. The black magic only requires 4.5", is it really that tight with the fan & spacer removed?

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-Charlie Ping
1970 Maverick Grabber
-1987 5.0L B303 roller cam/rockers
-1968 Mustang Toploader
-1977 Lincoln Versailles 9 inch w/discs
-1980 Granada Front Discs
www.MAVERICKGRABBER.com

An electric fan is on my shopping list.

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SteveLaRiviere/Webmaster -- MCA # 47773