Flex Fans for Cooling------------

[dpfurby]

Has anyone installed a Flex Fan in place of the stock cooling fan???
Looking to install on a '94 Ranger 4 liter engine.

Do they pull more air?? Is it worth the switch??

I am looking at Hayden and Dorman brands.

Any comments??

 

[90longbed]

they pull less air.... used one in my 4x4 and it would almost overheat on a 70 degree day..... use the stock fan or switch to an electric.....flex fans are for drag racers

 

[RonD]

I wouldn't think they would do much better than factory fan.

An electric fan is a better option, more cooling at low RPM, like when 4 wheeling, same cooling at high RPM when on the highway, so a plus there.
Also frees up a few horse power, since engine doesn't need to spin the fan, another plus.

But nothing is free , make sure stock alternator has the juice for the e-fan.
There are many models of e-fans with relays and temp sensors at the wrecking yards that will fit the Rangers with a little modification.
All the transverse mounted engine vehicles use them.

 

[adsm08]

A flex fan is to the regular fan what a Nerf gun is to a 30-30.

Cute, ineffective, and made of foam.

The only real advantage to a flex fan is if you are constantly pulling the engine.

 

[Frank The Tank]

I ran a flex fan on my Camaro. It was effective and it pulled plenty. The advantage is that when you go upstairs they put less drag on the engine... I don't see you hitting 6 grand much.

My FE build I just use a standard high performance 5 blade. Non flex. It's load and clutch less and I'd hate to see what would happen if it ever unloaded but low RPM cruising was a concern in traffic.

I have a GM single wire alternator and Optima so I will probably go electric when I'm not so busy.

 

[doorgunner]

A flex fan wouldn't cool my V8......it overheaed at every stoplight.....

You need at least 2,000 cfm blowing thru the radiator to keep stuff cool...

trust me...i am a doorgunner


FYI.......................

2" pitch fan blades/12" diameter shroud/1000 rpm electric motor

3.14 times radius squared

3.14 times 36 equals approx. 108 square inches

2" pitch at 1 revolution equals 2 times 108 equals 216 cubic inches in 1 revolution (Pitch: the distance of the fan blade from the leading edge to the trailing edge)

an e-fan that runs at 1000 rpm times 216 cubic inches would put out 216,000 cubic inches of air

216,000 cubic inches divided by 144(standard number) equals 1,500 c.f.m.

so......a 12"diameter e-fan that runs at 1,000 rpm puts out 1,500 c.f.m.



OR you can plug in the numbers below of the fan that you find at the junkyard to see how much output it has:

radius of fan blade Squared________" X 3.14 equals Square inches of fan surface ________" X fan pitch _____" equals airflow at 1 rpm ______ X rpm of electric motor _______ divided by 144 equals output of fan in C.F.M. _______

I learned that from Google

 

[alwaysFlOoReD]

2" pitch at 1 revolution equals 2 times 108 equals 216 cubic inches in 1 revolution (Pitch: the distance of the fan blade from the leading edge to the trailing edge)

Maybe in a perfect world. I wonder what kind of efficiency ratio to plug into that formula?

 

[Surrey]

Maybe in a perfect world. I wonder what kind of efficiency ratio to plug into that formula?

Indeed. Just because it can theoretically move that much air, doesn't mean it will.

This doesn't account for turbulence or air supply, for instance.

 

[85_Ranger4x4]

Keep in mind if I had room for a clutch fan I would have a clutch fan...

Started out with a 16" 2500cfm (IIRC) pusher efan that kicks on at 190*, it is the biggest fan that I could get to fit on a HD Explorer radiator. The first summer after I put a v8 in the truck it ran A LOT that summer. The next spring I changed a bunch of stuff on the front of the engine and added a low profile flex fan leaving the efan on the front of the radiator as a backup.

Now the truck has to sit and idle for quite awhile before the efan kicks on, if the truck is moving much at all the e-fan simply doesn't run.

I am very happy with mine for my situation, I really like having a fan that spins with the engine. If the engine is running the a fan is turning, it doesn't get much simpler than that. No modules/switches to go bad, no wiring for mice to eat, no electric motors to wear out... just a belt that you have to have anyway. Having the pusher is nice for when the thing isn't moving fast, I am glad it isn't my only hope.

Sometime it is going to be getting a regular 5.0 Explorer radiator that I hope will help it out more.

 

[doorgunner]

Maybe in a perfect world. I wonder what kind of efficiency ratio to plug into that formula?

Indeed. Just because it can theoretically move that much air, doesn't mean it will.

This doesn't account for turbulence or air supply, for instance.

Ain't this wonderful.....I'll be quiet since we got 2 Rocket Scientist working @ T.R.S.

 

[alwaysFlOoReD]

Ain't this wonderful.....I'll be quiet since we got 2 Rocket Scientist working @ T.R.S.

Sorry, I meant no disrespect. I was trying to say that in this case, bigger than the formula says is better.
Edit; and that formula makes perfect sense to me even tho it's the first time seeing it. I thought it was cool that you took the time to learn it and then pass it on - thanks.

Richard

 

[4.0B2]

Taurus 3.8L e-fan is the way to go IMO..
can get the Depo version on amazon for $78.
2 speeds, most people never wire the high side up lol.

 

[doorgunner]

Sorry, I meant no disrespect. I was trying to say that in this case, bigger than the formula says is better.
Edit; and that formula makes perfect sense to me even tho it's the first time seeing it. I thought it was cool that you took the time to learn it and then pass it on - thanks.

Richard

Eggzakly! (I was having a bad day....must have read too many Obama remarks)

We good!

(I'll call Eric Holder again & tell him to take yur name off his list)

 

[bowtieboy77]

I was warned not to use them by my engine machinist. He used to oval track 4cl mustangs and saw quite afew fly apart. I would say properly set up electric fans are hard to beat and draw minimum engine power.