I'm wondering if I have to much fan weight. I have the vicous[sp?] fan and the thing weighs a ton. Im thinking on going with a light weight flex fan and free up a few ponys.
What type of fan is everyone else running, and how heavy is it?

I use a stock fan. I would prefer a viscous fan drive like yours.

When the drive is disengaged the weight of the fan clutch doesnt come into play. I believe it is better than an electric fan because it doesnt drastically alter the car's appearance, and there is no efficiency losses from converting motion to electricity and back to motion. (When the electric fan comes on it loads the alternator and makes it hard to turn, which is normal but takes just as much hp if not more than a clutch fan would.)

I dont use flex fans because I dont have any faith in them. They dont flex enough at lower rpms to free up any low end grunt. Clutch fans only come on when theyre needed and hp is converted directly to cooling capacity; there is no heat losses from the alt and fan motor.

I havent crunched any numbers to come up with hard data to support my beliefs; they are just that, my beliefs.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

An electric fan only draws 20-30 amps at startup then much less to keep it going, the "extra" drag on the alternator is negligable. It only comes on when you need it just like a clutch or viscus fan. The only time "drasticly changing under hood appearance" comes into play is on a show car. that shouldn't be a determining factor in making you car more efficient.
Count one vote for electric here.

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Youre probably right. Im still curious though how the two fans would compare in horsepower draw. I think I said before this is in the nickle and diming territory; regardless whom of us you decide to listen to it won't hurt my feelings. Doing what feels right to you gets my vote.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I can tell you from first hand experience I could feel the increase in power going from the stock thick steel 4 blade fan to the electric fan. It was not an earth shattering jump but I could feel the difference, and every little bit counts when we are starting with around 90-100hp at the tires.

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I want to agree, but did your stock fan have a viscous drive fitted to it before you made the swap? If it did I apologise. I don't know everything, and I havent really researched my opinion, it just makes sense to me.

Maybe I was just unclear. I would NEVER argue a stock rigidly mounted fan over an electric one in terms of efficiency, to do so would be foolish. Whether you are putting a clutch fan on or an electric one you are definitely making an improvement.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I run a viscus fan on my engine, though I would like to convert to an electric fan in the future.

I have a super cheap aluminum flex fan that I bought at a swap meet for $5. It weighs about 12 ounces.

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Official Cookie and Mater Tormentor.

As stated on an earlier post my vote's for electric, though I'll admit that a clutch fan sounds like it could be just as good. It's mainly my preferance because I'm a wiring junkie

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My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.

My system - get a good aluminum radiator from Afco or Griffin (Afcoracing.com is better), and run a small (12-14" electric fan). Total cost is about $250 for radiator, fan (no thermostatic switch incl), and mounting. This will cool any Slant and you will very rarely have to turn on the fan.

Lou

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Home of Slant6-powered fun machines since 1988

This is hypothetical, but I thought that a fan's main horspower draw was from the rotation of the fan hitting a lot of wind resistans, not the weight of the fan, aluminum fans might be light and more aerodynamic, but wouldn's that also make them have less of a cooling capability. That would seem to be the advantage of the electric fan to me, it doesn't care about wind resistance, it pulls the same power no matter what, the only time it weakens the engine much at all is at startup and afterwards the fan's rotation not only takes little energy(somewhat) but also almost develops it's own. Also if you put in the thermostatic switch it'll only turn on when needed and not even take any pull from engine. Also I can say that after reworking my electrical system this weekend and using the relay to turn on the fan that even when idling the alternator can keep the alternator guage at a neutral position(this is when warm remember, cold it'll have more problems). Either way, like said before anything is better than the stock fan and preferance is mainly based on choice/beliefs and the only way to really resolve which is better is to do a dyno test with the same engine with different setups(I think it's cheaper and less time consuming to go on faith)

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My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.

I've switched to an electric fan. While you're in town, let's consider that as somebody says would'n make that big difference 'cuz of the alt load. The main advantage I see (and I've experienced) with the conversion is that when you can note the difference (cruisin thru highway, etc) and most of the times is off, even if you don't wanna take all the troubles I went thru and wiring three position switching (ON/AUTO/OFF) is that you'll notice the power gain. I don't want to exagerate but it even surprised me... at first reading posts here and there about the power gain I thought it was cheap talking, but it's true.

If you switch to an elec fan and wanna take all your chances, I've wired it using a double inversor 3 position switch under the dash, conecting the fan to the center pos, the thermo switch on one end and continuous power on the other. This wiring gives me the freedom of choosing between going auto (the thermo sw side) always off (center pos) or always on (the other side)

Most of the times when I'm in town, i use it on auto. when for any reason it tends to heat (like after having no mercy on the car, hehe) I switch to always on and I cool the engine at my cranky will, and when I'm on long cruise, I switch it off, then if I stop for refueling or anything like that I cool it down with either the auto or the always on pos.

Worked for me...

good luck!

I'm still skeptical that an electric fan outperforms a clutch fan. When the clutch is disengaged the fan isn't robbing any power from the engine. And just as a thermostatically controlled electric fan only comes on when it needs to, so does a clutch fan, and they are both moving the same amount of air over a given time period; only difference being the clutch fan is direct drive and doesnt lose any efficiency in the conversion.

I think the only reason one doesnt feel a drop in engine power when an electric fan comes on is because the battery lessens the impact of the sudden load, but the alternator still has to run in order to replace the power that was used.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Weather the fan is turning or not the clutch part of the fan is turning which is rotating mass. reducing rotating mass increases power. as for load on the alternator, it dosen't matter when the fan turns on it isnn't like the alternator turns faster to handle a higher load the second field just begins generating current. yes there is elactromagnetic drag but there is no extra rotating mass. the biggest advantage to the electric over the clutch is that the electric fan can give its maximum cooling at idle when sitting in traffic, it can pull much more air through your radiator then a clutch fan can at idle.

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This may be a stupid question, Im new to cars, but just how much power gain can one expect after converting from a stock fan to a clutch or electric fan?

-Greg