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clutch fan

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Old Feb 26, 2003 | 07:56 AM
  #1  
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clutch fan

would someone explain to me what a clutch fan is, and its purpose? i just would like to know what it does and everything. thanks

jjoel
 
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Old Feb 26, 2003 | 09:02 AM
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clutch fan

If you mean a fan clutch, then its purpose is to pull air across the radiator and a/c condenser. The fan clutch locks down when air coming across it reaches a certain temperature and starts to pull more air. At lower temperatures it spins freely at a lower speed than the engine (by design of the locking mechanism) to reduce drag and horsepower loss.
 
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Old Feb 27, 2003 | 08:23 PM
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clutch fan

It lets the engine warm up before the fan starts cooling it off.
 
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Old Feb 27, 2003 | 09:48 PM
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clutch fan

hahaha good response steve thats straight to the point and in my language hahahaha. alright. i wonder if that puts extra stress on the engine resulting in lower gas mileage hmmmmm.
 
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Old Feb 27, 2003 | 10:52 PM
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clutch fan

How could it put EXTRA stress on the engine? The clutch is normally DISengaged, until its thermostatic coil (visible on the front) warms up and turns the lock shaft. Then, it's no more a strain than an old solid fan.
 
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Old Feb 27, 2003 | 11:13 PM
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clutch fan

Maybe he meant the extra heat during warmup causing stress. But I agree, a quicker warmup doesn't cause any stress.
 
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Old Feb 27, 2003 | 11:16 PM
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clutch fan

You usually can hear and feel when the fan clutch locks up. The truck will roar and you'll feel the loss of power in comparison to when the clutch is disengaged. Alot of times when the fan clutch goes bad, it will simply lock up and the fan will spin just like a solid mounted fan. Gas mileage will definatley suffer then. Like 2-3 MPG. It's a good system when compared to a non-clutched fan. Some guys are adapting in electric fans and eliminating the fan and clutch system on the end of the water pump in hopes of power and economy improvements.

Randy
 
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Old Feb 28, 2003 | 01:10 AM
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clutch fan

How about those after market flex fans?
 
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Old Feb 28, 2003 | 01:46 PM
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clutch fan

I have a flex lite on my truck now till i feel good enough to put the electric ones back on. Its LOUD VERY LOUD. I got the 2" spacer with it but it still needs to be moved in another 1" I can notice the millage too. save up and buy the electric. Check out www.flex-a-lite.com
 
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Old Mar 1, 2003 | 12:44 AM
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clutch fan

I just purchased a 94+ Mustang GT cooling fan for $40 from Ebay (I love that place) with 12" of harness.

I will be taking my old flyswatter off hopefully in about two weeks and swap the electric in. I am using a Hayden adjustable thermostat w/ A/C relay.

Power gains are negligable usually around 5-10rwhp. But there will be no clutch locking up causing hard-core power loss and MPG loss in the summer. There will also be less parasitic drag on the accessories freeing up that power.

A single large fan usally draws about 20A. So with my 130A max alternator I'll be set, even with my underdrive pullies and my headlights on and A/C blowing. As long as I stay above 12v at idle all should be okay.
 
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Old Mar 1, 2003 | 12:07 PM
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clutch fan

Using an electric fan only moves the parasitic drag to the alternator instead of the water pump pulley. The power to spin the fan has to come from somewhere, and in fact, it takes slightly MORE with electric because of the resistance in the wires and inefficiencies of the alt & fan motor.
 
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Old Mar 1, 2003 | 12:10 PM
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clutch fan

Yes you are correct, but that is only when the fan is operational. Where as the factory fan is always spinning.
 
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Old Mar 1, 2003 | 12:14 PM
  #13  
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clutch fan

But when the clutch is unlocked, it drops to almost nothing. And whe the vehicle is driving faster than the fan is trying to pull the air, there is NO drag on a mechanical fan, where an electric is STILL pulling electricity.

I'm not saying an electric has NO benefits; I'm just saying it's not free, and no better than a clutch for power consumption.
 
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Old Mar 1, 2003 | 12:17 PM
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clutch fan

See, I've heard factory fans always create drag. Even free spinning and more at higher RPMs.

I suppose there are positives and negatives for both...
 
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Old Mar 1, 2003 | 12:41 PM
  #15  
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clutch fan

The engine isn't going to have to work any harder with a 30A electrical pull if you have a sufficient alternator. Seems like to me the electric fan would ease the load of spinning even a clutched fan, which does require some effort even when it is not engaged.
 
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