Fan/Pulley Question

westie47 · Mar 7, 2020

Do small blocks and big blocks use the same sized fans and pulleys?

I have a 7 blade fan on my 360 and wondering if it’ll work on my 440? Same with the pulleys, they look to be the same size.

TN Mopar · Mar 7, 2020

The length of the shaft are different on the fans
This is so the fans are the correct distance away from the radiator
The big block sits closer to the fan so the shaft is shorter

Just a guess on this one but I doubt the pulleys will interchange due to the length of the water pump snouts

Darter6 · Mar 7, 2020

Depends on year, options like p.s. a/c etc. Water pump depths differ for small block early/late. I have found several big block water pump pulleys that differ too. Some single crank pulleys are the same.

westie47 · Mar 7, 2020

Is the overall size of the fan blades the same? I notice the bolt pattern is the same, just wondering if a big block fan has bigger blades

TN Mopar · Mar 7, 2020

I believe the fans themselves are the same
The shaft length is the difference

westie47 · Mar 7, 2020

TN Mopar said:
I believe the fans themselves are the same
The shaft length is the difference

By shaft length, do you mean the spacer? I’m not quite following.

SureGrip · Mar 7, 2020

westie47 said:
By shaft length, do you mean the spacer? I’m not quite following.

The shaft coming off the front of the water pump. Sort of like this:

There's dozens of different size/shaped pulleys depending on accessories, as Darter6 said.

I wouldn't count on re-using the pulley, even if it will physically bolt onto your big block water pump. You 'should' be okay on the fan though.

TN Mopar · Mar 7, 2020

westie47 said:
By shaft length, do you mean the spacer? I’m not quite following.

I should have explained myself better and I had a brain fart
I was referring to the viscous fan clutch fans
I forgot about the simple fan/spacer combo
But as Suregrip stated each water pump combo requires a matching set up

I do apologize for any confusion I may have caused

westie47 · Mar 7, 2020

TN Mopar said:
I should have explained myself better and I had a brain fart
I was referring to the viscous fan clutch fans
I forgot about the simple fan/spacer combo
But as Suregrip stated each water pump combo requires a matching set up

I do apologize for any confusion I may have caused

View attachment 919463

No worries, mine is just a regular fan. I believe the clutch fan was for heavy duty cooling packages?

TN Mopar · Mar 7, 2020

westie47 said:
No worries, mine is just a regular fan. I believe the clutch fan was for heavy duty cooling packages?

yes mostly
It also used in performance applications because it doesn't eat as much horsepower
I bought one years ago from Mopar Performance and it hit the radiator on my big block
This is how I learned about the different shaft lengths and the first thing that came to mind when I read your question

Fan/Pulley Question

westie47

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TN Mopar

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Darter6

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westie47

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TN Mopar

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SureGrip

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TN Mopar

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