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Got the car out on the road and noticed the temp was hovering around 200 degrees. New high volume H20 pump and copper 4 core radiator. Engine is newly rebuilt (454). The temp outside is around 65 degrees so when it ramps up to 90-95 things will get much hotter. The only thing I can think of is the clutch on the fan may be getting old and in need of replacement.
Is there a way to test it? I turned it by hand and there is resistance.
 

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My neighbor tries to stop the fan while it's turning using a heavy shop rag, not recommended!!! If the car is up to temperature, shut it off while someone watches to see if the fan free-wheels. If it does, probably time for a new one.
 

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I always thought that if after you turn off engine, if the fan keeps spinning then the clutch is bad.
 

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If the car is up to temperature, shut it off while someone watches to see if the fan free-wheels.
Wrong.....the engine can be up to temp, thats fine, doesnt mean the clutch engages
I dont know the temp, but considerring the temp idoit light is 235 deg, I would imagine the clutch would be up there somewhere.

I did some digging of info yrs ago...boiled down to the clutches very rarely fail if ever...the bearings do....has it play in the bearings?

Once you get upto 20/30 mph there is far more air going thru than the fan ever will put thru.....If it still runs hot the temp gauge is either out or something else in the cooling system is not working....or have a crome/polished sump/tappet covers...to much polished stuff that retains heat...which is why car manufactures for a 100+ yrs have black/painted sumps and radiators.
More heat is disipated thru the oil than thru the cooling system.
 

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I've failed a few on my 72 BBC- my experience is that the clutch locks up then fan no longer "freewheels". Engine pinging from the increased fan load is the first clue ...seems a bit odd it has that much effect..
So..if its cool and locked solid its toast..never had one fail in the other direction i.e. freewheel when hot ..
 

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This is how I test them.

After driving for a while, I'd say 30min, and with the engine off spin the fan over with your hand. It should not turn over more than 1 revolution. If it does it is bad.
 

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I always thought that if after you turn off engine, if the fan keeps spinning then the clutch is bad.
I read here a couple of years back to roll up some newspaper and try to stop the fan.
No offence meant but theres a lot of ppl out there that read hear stuffand never varified it...most old wives tales

After driving for a while, I'd say 30min, and with the engine off spin the fan over with your hand. It should not turn over more than 1 revolution. If it does it is bad.
I had a 'theory' when I put my new one in...because of stuffed bearings....that something like that 'should work' but never noticed any difference...but I never had running hot issues....runs max 170 (low due to the fuel I run)...it just free wheeled and still does like normal...
Im bloody sure temps have to get up (like I mentioned above) around 220 or something.

Also note there are several types for different applications
 

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Have you checked your thermostat? What is the actual opening temp? I would think going down the road with an outside temp. of 65 degrees the engine would be operating at what ever degree thermostat you have.
What is the temp. when you are stopped, say in slow traffic.

Got the car out on the road and noticed the temp was hovering around 200 degrees. New high volume H20 pump and copper 4 core radiator. Engine is newly rebuilt (454). The temp outside is around 65 degrees so when it ramps up to 90-95 things will get much hotter. The only thing I can think of is the clutch on the fan may be getting old and in need of replacement.
Is there a way to test it? I turned it by hand and there is resistance.
 

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Discussion Starter #13
I have a 160 degree thermostat in the car and after reading up on the subject here, realized that the t-stat does not determine engine running temp. Didnt know that. So, the fan is probably working, the t-stat should be a 180-195, and I am considering changing over from a 4 core copper radiator to an all aluminum radiator. Found one that is an aftermarket factory replacement for $248.00. Heard good things about their ability to cool.
 

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On a thermal clutch fan at first start up you should feel the fan pulling air for about 3-5 seconds, also the thermal doesn't engage the clutch until 190* and above... So if your temp is high then check to see if the clutch/fan is pulling lots of air threw the grill or just pop the hood and you can feel it.

On a non-thermal clutch fan will be pulling lots of air at idle no matter how hot or cooled its is then free up at a certain rpm.
 

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But Skeeter, how would a non-thermal clutch free up? Are you talking about a fan without the clutch, just a straight bolt on item?

alan
 

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A non-thermal fan clutch frees up after say 2500-3000 rpm, otherwise, always engaged especially at idle.

As Skeeter suggests, a thermal fan is engaged at cold startup for a length of time, then disengages until spring expands and allows clutch to lock up.
 

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Discussion Starter #17
Wrong.....the engine can be up to temp, thats fine, doesnt mean the clutch engages
I dont know the temp, but considerring the temp idoit light is 235 deg, I would imagine the clutch would be up there somewhere.

I did some digging of info yrs ago...boiled down to the clutches very rarely fail if ever...the bearings do....has it play in the bearings?

Once you get upto 20/30 mph there is far more air going thru than the fan ever will put thru.....If it still runs hot the temp gauge is either out or something else in the cooling system is not working....or have a crome/polished sump/tappet covers...to much polished stuff that retains heat...which is why car manufactures for a 100+ yrs have black/painted sumps and radiators.
More heat is disipated thru the oil than thru the cooling system.
Steps,
Problem solved. You were right about the clutch bearings. I grabbed the fan blades and moved them back and forth, lots of play, maybe 1/4 inch. Although the bearings felt fine when I assembled the pieces together (tight with no play) When attached to the engine, I could really work the blades and then it became apparent the bearings were bad. I had to pull/drain the damn radiator to install the new clutch. What a hassle. But, it paid off. The temp never got over 180. 185-190 with the AC on. Temp outside is around 88.
Not sure why this fixed the 200+ temp problem though. The fan did not "freewheel" when I spun it. It seemed to be in perfect shape.
 

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Louie install a Flex fan and forget about it. They work great. Flex O Lite # 1318 I believe.
 

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Good stuff Louie

It seems there are not enough ppl who has seen a blade cut a hood, or slice open a radiator, or hit a bystander in the shoulder....these things should have been banned 40 yrs ago....and they are no where as efficient as what the manufactures make out in their propaganda BS.
 
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