Fan Clutch

TOMRR · Aug 16, 2018

I need to extend my fan on my 69RR 440 HP closer to the radiator.it is into the shroud by only very little. needs to be at least 1/2 way into shroud from what I have been told My current fan clutch is a 070. does it make sense to add a spacer, I would have to use studs to do this, or should I get a fan clutch with a longer shaft. The engine runs at 1/2 on temp. gage, when driving but heats up to a little under 3/4 if left to idle for very long.

Thanks Tom C.

PurpleBeeper · Aug 16, 2018

I'm sure there are others on this board who know more specific information, but I will throw out some general ideas.
a. I think you're idea of moving the fan closer to the radiator & further into the shroud area makes a lot of sense for cooling at idle.
b. There are fan clutches of different "lengths" which work the same, so maybe just a "longer" fan clutch would work?
c. I personally don't see any reason why you couldn't just use your existing fan clutch with a spacer, but you're right that you may need some longer studs on the water pump. I think some spacers come with longer studs & you can also find/make something from a hardware store. Or should I just say longer bolts?
d. Are you SURE your current fan clutch is working? With the motor off & the engine cool, the shouldn't spin very well by hand...maybe 1/2 turn or so, if the fan clutch is working properly.

TOMRR · Aug 16, 2018

PurpleBeeper said:
I'm sure there are others on this board who know more specific information, but I will throw out some general ideas.
a. I think you're idea of moving the fan closer to the radiator & further into the shroud area makes a lot of sense for cooling at idle.
b. There are fan clutches of different "lengths" which work the same, so maybe just a "longer" fan clutch would work?
c. I personally don't see any reason why you couldn't just use your existing fan clutch with a spacer, but you're right that you may need some longer studs on the water pump. I think some spacers come with longer studs & you can also find/make something from a hardware store. Or should I just say longer bolts?
d. Are you SURE your current fan clutch is working? With the motor off & the engine cool, the shouldn't spin very well by hand...maybe 1/2 turn or so, if the fan clutch is working properly.

Thanks for reply The 070 Fan clutch has been rebuilt. can not use longer bolts not enough space between fan and pulley so would have to use studs and would lock tight them in to water pump

beanhead · Aug 16, 2018

How long is the clutch you have? This one is from the Mopar Performance 'viscous fan' kit I think I got it from Mancini's years ago. 3.25 inches measured from back of mounting flange to front edge as shown

It was too close for comfort with my aftermarket radiator. (The Hayden 2947 was ok but a little short. I settled on a heavy duty unit out of a '76 or '78 440-equipped RV ).

Dennis H · Aug 16, 2018

Hard to diagnose thermal fan problems. Critical though. Use a laser temp gun to be sure of actual temps. Mine creeps if ambient around 100 and depending on circumstances. Clutch fan is working.

Frustration · Sep 4, 2018

Beanhead, Is the motor home clutch shorter? I am too close to the radiator on my 64 Fury. Can't use a clutch fan on it. Is the one you settled on shorter? Do you know how much shorter? I am currently running a flex-fan with little luck. Traffic is a nightmare in the 90+ degree weather. Tom

rarefish · Sep 4, 2018

Here is a picture of the Hayden HD fan clutch #2947. It is 2-3/4" tall. It is the shortest one that they make for Chrysler cars. I'm pretty sure that the 070 fan clutch was the shortest one that the factory made. I believe that it is 2-1/2" tall.
The Hayden 2947 clutch is a thermostatic one and the 070 factory clutch is a torque style one.

beanhead · Sep 4, 2018

Frustration said:
Beanhead, Is the motor home clutch shorter? I am too close to the radiator on my 64 Fury. Can't use a clutch fan on it. Is the one you settled on shorter? Do you know how much shorter? I am currently running a flex-fan with little luck. Traffic is a nightmare in the 90+ degree weather. Tom

You'd have to measure yours to know for sure. The RV one I'm using is about 1/4" shorter than the Mopar Performance unit in my above picture. The 2947 is the shortest one I've seen; shorter than my RV clutch and a good bit shorter than the Mopar clutch which is supposed to be a stock replacement. I have one of the 2947s too but the RV clutch got the fan as close as possible to the radiator without being too close, plus there's a a tad more room to get the bolts in the pulley. See how much room is between your radiator and the face of your pulley, you want a clutch that's about 3/4" or 1" less than that overall.

Fan Clutch

TOMRR

Well-Known Member

PurpleBeeper

Well-Known Member

TOMRR

Well-Known Member

beanhead

May I Land My Kinky Machine..?

Dennis H

FBBO Gold Member

Frustration

Well-Known Member

rarefish

Well-Known Member

beanhead

May I Land My Kinky Machine..?

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