Inliners International Forums General Discussion Engines Electric vs Standard Fan

Is there a noticeable increase in HP or MPG by switching from the stock crank-driven fan to an electric fan? Do any of you guys use em?

At low speed the fan burns amps pretty quick because it runs at idle when your generator output is nearly nothing.
Above 35 mph you can turn it off completely and save some gas (and noise).
At high RPM, the mechanical fan wastes at least 15 hp.

Personally, for you, I would use a clutch fan.

Unless you have all the correct parts to use an electric fan,IE, radiator,& other supporting items,,,,stick w/a clutch fan.

Your mechanical fan robs almost the most HP, but it cools great!

Two cents thrown.

MBHD

MBHD

X2

15 HP - wow - that's alot more than I would've guessed. How much does a flex fan take in comparison?

Not sure about flex, they're supposed to flatten out to reduce drag but I've read a lot of comments that this doesn't happen as much as they say.
For any mechanical fan, the best efficiency is the largest diameter, most blades, and turning at the slowest speed. The fan's air movement increases as the square of diameter, so even a small change helps.
HP loss goes up with the cube of RPM: 2,500 uses almost twice the power of 2,000.
For comparo: a 19" fan turning 2,000 RPM moves the same air as an 18" fan at 2,228 RPM, and uses 28% less power.

I have never had good look with a flex fan. I also recommend the clutch fan for street use. There is a regular and a heavy duty, I always get the heavy duty.

The clutch fans are what the factory supplied for cabs, A/C cars, towing packages so they have good reliability and life expectancy.
I've never had a flex failure, but I've read that breakage severs the hoses, belts, punctures the radiator core, and you get a lobotomy if the hood is open.

So does anyone know which brand of fan clutches are any good? When I Google I see Flexalite, Hayden, Torqflo.

Haydens are good,,,clutch needs to have the spring on the center of unit.

The less $$ ones do not have the external spring.
http://www.haydenauto.com/Featured%20Products-Fan%20Clutches%20and%20Fan%20Blades/Content.aspx


MBHD

K5, you should be able to get one from whatever local auto parts affiliate you have there (Never Any Parts Available, etc).

I got the last one I bought at NAPA (they actually had it too, I was shocked).

I too reccomend the clutch with the spring in the middle, as that's supposed to release the clutch some more when it's cool, and engage it more when it's warmer.

Nice feature that.

I'm using it in a snow plow truck, it has the bent 8 that it came with still, I've been contemplating swaping an inline into there, inline turbodiesel that is.

I think I have posted this before at http://www.fordsix.com:

I ran a back-to-back dyno test on a Ford truck modular V8 with a clutch fan disengaged and then fully engaged.
Disengaged it sucked 1.5 HP max.
Engaged it sucked 14 HP max (around 5000 RPM max test speed).

Make sure to shroud anything you use for effiency nad for the most part only use a "pusher" electric fan if you have no other option...Good Luck