Air Flow Rate of Clutch Fan

[88pioneer]

Does anyone know how many CFM the stock clutch fan produces? I am asking because the 89 i just purchased is missing the clutch fan and i was wondering if it would be better to install an after market fan or just go with stock. Whichever i choose will be run to a switch, so i'll do all the wiring for it.

[HOrnbrod]

Impossible to answer. The viscious clutch is controlled by a bi-metallic sensor that reacts to the ambient air temperature from the sensor heat exchangers. The CFM is most (if the clutch is operating correctly) when the sensor detects the most heat.

 

If I had to guess and the mechanical fan was "hard wired" w/o a clutch, I say it moves maybe 1500 CFM tops. But this loads the engine if there is no duty cycle. I prefer two electric fans. :cheers:

[cracker]

I have heard of good success with a clutch fan from a grand cherokee.

 

Unlike hornbrod, I prefer the mechanical fan and the auxillary electric fan out of a late model XJ.

[88pioneer]

Mine is hardwired in my 92. i was just looking at my options, since i figured i'll hard wire either one any way. It will only see street duty so it shouldn't be faced with too much heat. thanks for the input

:cheers:

[HOrnbrod]

I have heard of good success with a clutch fan from a grand cherokee.

 

Unlike hornbrod, I prefer the mechanical fan and the auxillary electric fan out of a late model XJ.

 

I too prefer the 10-blade electric fans from the 1997+ XJs as they pass more average CFM than the mechanical fan, but two of them (one replacing the mechanical fan). You wire them as both sensor controlled, but with an override switch in case of sensor failure. No worries in any conditions. Easy to do in an HO.