Topic: FAN CLUTCH
in Forum: C3 Cooling and Heating Systems
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Former Member
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
HOW MUCH RESISTANCE SHOULD THERE BE ON THE FAN CLUTCH WHEN THE VEHICLE WAS RUNNING FOR A HALF HOUR.
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I'm not an expert but after 1/2 hour of run time my 77s fan clutch has fairly stiff resistance. If you shut the engine off after it reaches normal temperature range (165-195 Deg F or so) you should not be able to spin it freely and there should be moderate resistance.
Hope this helps!!
Mel
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Former Member
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
MINE HAS NO RESISTANCE, I WILL GO TO SPIN IT AND IT WILL TURN 1/4 OF THE WAY COMPARED TO 1/2 OR 3/4 WHEN ITS COLD, IS THIS NORMAL.
Former Member
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Mounds View, MN - USA
Joined: 5/24/2007
Posts: 1031
Vette(s): 70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe
That is a function of temperature. The hotter the the clutch body, the tighter it should get so it turns the fan and cools the engine.
Larry
Larry
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If you are interested in more details go here; http://www.popularmechanics.com/how_to_central/automotive/1772922.html
corvette440hp
Years ago I remember there was available an adapter that lets you remove your fan clutch and allows the fan to turn full time. I don't know if these are still made or if it is a good idea to use them on a Vette.
Aaron 
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I did a search and found spacers available so you can remove your fan clutch and have your fan run full time as well as some pretty cool flex fans that help cool better than stock fans. You can get them in colors also.
Aaron
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Lifetime MemberGreensburg, IN - USA
Joined: 9/24/2003
Posts: 5188
Vette(s): Previous: 1984 Silver / Charcoal Coupe, 1988 Maroon Coupe / 1989 Artic White Coupe / 2001 Speedway White Roadster / Present:1976 Stingray Black / Black, Auto, 350 slightly modified (355 hp) Luxor Wires Redline Tires. / 1989 Roadster Bright Red...
I took mine off and am running a flex-cool fan. Spins all of the time but the blades adjust to the speed the fan turns to draw air.
Former Member
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Mounds View, MN - USA
Joined: 5/24/2007
Posts: 1031
Vette(s): 70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe
If you can figure out your fan clutch problem, that seems to me to be the best answer. The flex fans don't move as much air at idle, and use more power at speed. And they usually are noisier. They are also cheaper than a good fan clutch, so choose your poison.
Larry
Larry
My question would have to be, is your car running hot? You can tell if the fan is turning fast enough just by the amount of air its moving when its hot. Plus a lot of times when they go bad you will see some leakage out the back side. I've had them before where you can actually stop it with your hand when its running. If the clutch is working right, I agree with Larry, thats the way I would go.
in Forum: C3 Cooling and Heating Systems
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