Flex fan

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A Body 440 WHY NOT

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Just a question ,
Why is everyone so against a flex fan ?
( other than being sharp edged )
Asking for a friend. LoL :rofl:
 
The theory is that they come apart and fling razer blades at people.

IMHO, if they were so dangerous they would not be sold. My guess is any that fail, fail for over RPM, or external damage, or really old age.

It feels like a wives tail, though I am sure there are members here who have first hand knowledge of a fan letting loose.
 
I’m using one on my 65 dart, when I swapped to aluminum radiator my stock fan didn’t fit with the spacer. I painted flex fan black make it look stock. Works fine did cut me up installing tho lol.
 
But seriously,
street car. < 6000 rpms.
Tight space.

I hear people say they fly part ?
Is that true ?
They say tested to 9000.
 
I'm using one, 17" if I remember right, and either a 1/2" or 3/4" spacer to move it closer to the aluminum radiator... It weighs a LOT less than the stock fan. I didn't weigh the original after I took it off. I'd like to see how much weight I'll have shaved off when I get done. I bet it's a LOT. (Gotta make up for my fat ***).
 
I think the "fly's apart" ones are the plastic or fiberglass ones.

I had to run an thin 18" Hayden one with my Cold Case Rad and power steering pump combo. Not a lot of room due to the add thickness of the core and even the short thermostatic clutch was too tight on room and I didn't even get to fitting a fan.
 
"Back in the day" the fiberglass ones came apart... but the rivets were never checked.
Even the Cal-Custom units had a note asking you to check the rivets every 3,000miles.
the good ones like Flex-O-lite mentioned checking tightness every so many miles for wear and such.
They have their purpose and worked fine for most.
 
Terrible but true story.
When I was a kid the very cool hot rod teenager mechanic was found dead leaning over his engine compartment.
Flex fan piece sliced his carotid artery.
Flimsy lightweight metal at high rpm? No thanks.
I vowed to stay away from them, not worth the 10 hp gain.
 
Terrible but true story.
When I was a kid the very cool hot rod teenager mechanic was found dead leaning over his engine compartment.
Flex fan piece sliced his carotid artery.
Flimsy lightweight metal at high rpm? No thanks.
I vowed to stay away from them, not worth the 10 hp gain.

Guess he did not read the note. Yikes -gorry story
 
Compared to what? I don’t do MTOD. We hate each other.
If i remember correctly (i saw the episode a while ago) they compared a clutch fan, aluminum flex, plastic flex, and factory fixed fans, to no fan at all.
Clutch fan did the best, memory says -10hp, alum flex -15, plastic flex -25hp, fixed -30 or 35 hp.
It got my attention cause i use the plastic fan that they tested. I made a concious decision to use it cause it keeps my engine cool. I used to play around with electric fans and water pump drives to save power on a bracket car. That is, till i figured out that the power i was supposed to be saving wasnt really there, cause the engine was too hot all the time.
 
Once I went electric fan I never looked back.. no more whirling blade of death..

Elec. fans (tried many) wont keep my car cool , period .
They do make 8,000 , and 10,000 rpm flex fans !---------jfyi
 
I had one come apart on me years ago. I will NEVER run one of those thing again! It was the steel type. The rivets were still in the fan, the blade tore loose. I remember Volvo had a recall on them for that very reason.
 
Back in the 90s had one on my Swinger came apart in the burnout box and went through the hood. Don't use them.
 
Just a question ,
Why is everyone so against a flex fan ?
( other than being sharp edged )
Asking for a friend. LoL :rofl:

For me they look cheap. I don’t like the look of them.
On the practical side, there cheap to purchase BUT give up HP.
These (most) are also made cheaper.
The OE fan is an excellent cooling fan with the best being the old MP Viscous fan cooling the best while eating the least HP.
(Check Mancini for there version or if they have any of the old 5 blade MP stuff.)

This is one of the factory parts that is worth the price of admission. Looks stock and allows the best power while working like it should. A
Like a quality OEM part should.

I use the OE/MP 5 blade viscous fan on all of my stuff. Except the balls to the wall drag car. Use it with a shroud and at least 3/4 of an inch from the radiator for best results. The fan blade should be about an equal half in and half out of the shroud for proper operation. These units REALLY move some air!
 
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I have run Mopar OEM flex fans. No problem. However, I also never liked the look of aftermarket flex fans.
 
My '78 Van had the factory flex fan. It was noisy, removed it at overhaul and installed a clutch fan. Probably not an issue with a noisy muscle car.
 
They pull a lot of air at idle. It was the only fan that would keep my Dodge truck happy at extended idle. I tried everything else. Plus they are dirt simple.
 
Don’t use a flex fan, they are dangerous and sooner or later will let you down.
It’s just like bending a paper clip back and forth, do it enough times and it is sure to break!
 
We have a member who was seriously injured by a flex fan coming apart. I don't remember who it was. If it had cut him much worse, it would have sliced his arm off at the shoulder.

Here it is. It was @chryslerfat. Picture of the injury is on the last page. Pretty brutal. Speakin of which, @chryslerfat , how's your shoulder doin now?

*MUST READ*--Flex Fan Danger--Be very careful working on old cars


Two things...

DAMN THAT WAS BAD.

And WAY TOO MANY guys have passed since that thread was posted.
 
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