Which fan should cool better?

[mopowers]

I'm in the middle of installing a new aluminum Champion radiator and have two fans to choose from. Currently, I have a fixed mechanical 17" 7-blade fan. I also have an 18.5" '216' 7-blade clutch fan w/ thermostatic clutch I could use.

Which would you choose? Thanks.

 

[TrailBeast]

The clutch fan.
No doubt
Positive
Absolutely
For sure

Can ya tell what my opinion is?

Hope you have a shroud.

 

[mopowers]

The clutch fan.
No doubt
Positive
Absolutely
For sure

Can ya tell what my opinion is?

Hope you have a shroud.

I'm going to make a shroud.

Why do you prefer the clutch fan over the mechanical? Is it just the size, or do you prefer clutch fans in general?

 

[krazykuda]

I'm going to make a shroud.

Why do you prefer the clutch fan over the mechanical? Is it just the size, or do you prefer clutch fans in general?

Clutch fans disengage at higher rpm when not needed at highway speeds. They "coast" when the air rams through them at high speeds versus the standard fan that always turns and may block some of the air at highway speeds...

 

[cu440da]

X3 ^^^^

Always go with a fan clutch if/ when possible with mechanical driven fans.

 

[ir3333]

Clutch fan may save a bit of power but they only turn about 80% of crank speed at low rpm and you may run warm at lo speed or idling.
They are heavy and hang on the end of your water pump.

..may be fine for your build.

 

[mopowers]

Clutch fans disengage at higher rpm when not needed at highway speeds. They "coast" when the air rams through them at high speeds versus the standard fan that always turns and may block some of the air at highway speeds...

I understand what you're saying. But technically, they don't 'coast'. They just allow the fan to spin at a lower speed when hot (say 20-25%), right?

Either way, thanks for the input guys.

 

[ntsqd]

Another clutch fan vote.

I don't know about the 20% slippage at low speed. Seems like they're basically like a torque converter (non lock-up), so some slippage is likely, but 20% is excessive. Torque converters slip in the 3%-5% range form what I've been told. I'd expect a similarly low slippage from a clutch fan clutch.

 

[tekslk]

Fan clutch will free up horse power, enough that you can feel the difference. If it wont cool things for you, than you got other problems.