5 or 7 blade viscous

[Cazbah362]

OK folks, which is better, the 5 blade which I got as a part of the MP 6 pack set-up or an industrial 7 blade, both viscous both the same size?

 

[RustyRatRod]

IF the 7 blade fan is asymmetrical, it will move more air.....but not by a ton. If the 7 blade has the blades spaced evenly, the MP 5 blade wins out. Those aluminum 7 blade asymmetrical fans are about the best ones. They're light and they really move the air.....although all of them I've ever seen were 20" while the MP 5 blade is 18.

 

[Cazbah362]

Rusty - Thank you, this is what I was looking for. Both are the same size, the industrial 7 blade is all steel and the same size as the five blade, five blade seems a bit lighter. Either way, had the 7 blade on and think the clutch was going, was warming up at idle, now trying the five blade, will post what I discover.

 

[terzmo]

I've found that a 7 blade steel fan does the best drawing air through the rad

 

[RustyRatRod]

Might be true compared to a flex fan, but an aluminum fixed blade fan will move as much air as its steel counterpart, and have much less wear on water pump bearings doing it. Like this one. See how the blades turn on the end? Not all of them are like that. That's the extra heavy duty cooling fan. They move some air.

 

[Cazbah362]

Rusty - that is a monster - The 7 blade I have does not curve like that one, the blades are smaller and thiner. I will take a shoot of the two this weekend and post. Drove the 5 blade last night, no shroud and too close to the radiator - 205 all day long, think a shroud would bring it down a bit

 

[RustyRatRod]

It is a monster and it'll do the job. It's also a light monster, since the blades are aluminum. Far as I'm concerned, it's the fan to have.

 

[Cazbah362]

Do you know where to get one? Here is what I have for the 5 blade and clutch

 

[RustyRatRod]

Do you know where to get one? Here is what I have for the 5 blade and clutch

Sent you a PM, buckwheat.

 

[terzmo]

I've always had best results with a 7 blade fan

 

[fatecaptured]

the 7 blade I had in the trunk of the charger was a ford piece. But if fit and worked. Any thoughts Rusty?

 

[68 Sport Satellite]

Sent you a PM, buckwheat.

Rusty - can you PM me a part # and source for that 7-blade curved and staggered viscous fan? I'm shopping for one for my 451. Thanks!

 

[Meep-Meep]

I can't comment on which style of fan (5 blade or 7 blade) moves more air but the unequal blade spacing is to change the natural frequency to deal with noise (i.e. for quieter operation).

 

[clemul]

Rusty, can you please PM me a part # and source for that 7-blade curved and staggered viscous fan? Thanks much for any and all help..

 

[RustyRatRod]

I just hawked Ebay for mine.