Considering you only need a fan at 40 mph & under, the size and strength of various fans is very under rated. When I crank my 3.8 fan to high, the observers (and doubters) eye brows arch dramatically in amazement. The actual air movement is equal (at idle) to what a fully locked up fan clutch would produce at (I would say) over 4000 rpm.

If durability is an issue, mine is a big, honking Siemens (OEM, stamped on the side) motor & new. Starting on second, deep south summer with it.

 

I really think you need to do some research and then more research !!! At this time 2012 GM trucks are running twin electric fans... and that is with a huge under hood area. as for the "mini-van fans" they are designed to cool 3.8's that run at a MUCH higher temps. Plus in a very compact compartment where you would need to have increased air flow to eliminate under hood heat. Next there is the MPG side if the fans... It only requires about 2.5 HP to run an alt. to provide electricity to run these fans at full speed, and less than that the rest of the time. Those BIG BUMP stereo's and amps use much more than that.
The old clutch fans use up to 25 hp when fully engaged. I also installed a 3G alt, which in general allowed the truck to operate all the basic functions better !!! And finally I DON'T do anything on ANY equipment without plenty of research and facts... try it !!!

 

You need to study some physics. Larger engines doing more work produce more total heat--it doesn't matter what temperature the engine runs at (the difference is only 10-20 degrees Fahrenheit). Remember, I'm talking about the cooling/airflow needs when the larger engine is being pushed to its limits. The larger engine is probably a little less efficient overall anyway (in terms of converting the potential energy of the gasoline to work), which means even more fuel is converted to waste heat that must be dealt with.

Secondly, if the clutch fan is using up to 25 hp and the alternator is only taking 2.5 hp to run the electric fans, which fan is pushing more air?

Jason

 

Jason, I don't understand physics and would never claim to... but I do understand automotive and mechanical applications and the cause and effect of changes to vehicles. Any motor will need more CFM thru the radiator at lower speeds and that is where electric fans win out, providing "FULL CFM @ LOWER RPM". When you're moving at 35 mph+ EVEN pulling a load up a hill, the original fan is of minimal use.

I drove class 8 semi trucks for years (40+) we had air operated fans on all our 500+ hp motors. and running here in the CA & NV desert at 100* +/-- and I could hear and feel the fan come on and off ... So I can tell you they don't work all the time even on a hard pull. they are controlled by a thermostat just like the electric fans do. They also have an over ride/ manual switch that is only used for if something fails. You can run the fan on all the time but fuel MPG is an issue (they use 75+ HP) ... with the fan on all the time it gave about 4.3 MPG and operating on it's own 6.7 MPG weather in my pick up or my semi I am running a bigger motor not some little sewing machine thing !!!

 

Dont forget about the battery storage. The sudden surge will be pulled from the battery then the alternator will kick up the charging amps. As long as the battery is good shape, the alternator will not take out much HP from the engine. It spreds out the power load over time while charging the battery. That is a big confusion part with electric fan installs.

On my E350 bus, when the clutch fan kicks in, I can feel the power drain out of the engine. I am looking in to doing this my self, but I will need a 2nd alternator as I run dual AC system: 3 fans on side condenser and 2 for evaporator in rear. When they are on, I don't feel power loss but I see the voltage is down to 12V level!

 

Good point, I have always run the maximum battery I can fit in the allowed area. My current battery is a 65/70 series with 1000 cca, and it replaced an exact same type and size that finally gave up after 6+ yrs of great service.
I'm not sure about you application, but I've seen the heavier duty "ambulance" alt's that give upwards of 200+ amps. I think they run an 8 rib serp belt to turn all of that. I would think a good truck/commercial electrician to plan a system to fit your needs, with one alt. Good luck with it

Dave

 

Still nothing close to 25 hp. Every electric fan motor I've ever seen is small, and when it comes to motors you don't get power without size and weight due to the copper windings. I have a floor sander that has a 7.5 hp motor--it weighs close to 150 lbs by itself. Power = airflow.

I can guarantee you that the bean counters at Ford didn't let the engineers over-design the minivan electric fans (plus they couldn't easily/cheaply put a belt-driven fan on a transverse-mounted engine). A fan/clutch setup is simpler and cheaper (and far more powerful).

Sounds like a lot of extra work for negative benefit. An extra load on the engine while driving just means you might go a bit slower. Extra load on the battery/alternator may mean you don't go.

Jason

 

So what kind of brackets did you have to fabricate for the Windstar fans? Were they a direct fit? I'm assuming not. Just curious if it's easier to buy a kit made for my truck from LMC or make something.

 

When I had the rad. on the bench I placed it so I got the minimum openings on the sides. The top and bottom coverage was not an issue.
On the bottom I attached a full width piece of 1/2 " aluminum angle 3/16 thick with(5) 1/4x20 button head bolts, fender washers and ni-lock nuts with the angle fitting in the original fan shroud clips on the radiator.
The top got 1 1/2 X 3/16 aluminum angle attached to the 2 top bolt holes for the original shroud.

I used 1/8" rubber gasket material to sandwich the plastic shroud between all the angles and bolts and washers
(angle,rubber,shroud,rubber,fender washer,lock nut)
Then covered any side gaps with the rubber.

The only shroud trimming I did was the factory Windstar mounting side tabs and the lower left radiator hose area for my truck and just a bit on the upper right for better fit. I set the fan unit favoring the left(drivers side) leaving minimal gap on the other side. FIT NOTE: if you use the auto-trans cooling lines in the rad you'll need to trim for them too!!!
BE CAREFUL the plastic in the Windstar shroud can be brittle. I did my rough/basic cuts with a fine blade hacksaw and finished with a 4 1/2" hi-speed grinder with a 120 grit flap type sanding disk ... take your time !!!

Cost for... JY fans $40... aluminum and rubber and bolts $25... Hayden adjustable thermostat $18 ... Relays, circuit beakers and wiring... had some but extras $20 max. I have about 3hrs involved ... so far !!!

Good luck, keep us posted !!! Dave

 

Cool....I'm printing this to do mine!

 

If you have any more ????'s let me know... I'll try to help, By the way, I got the rubber material at an industrial hardware supply house... sold off the 36" wide roll @ a per foot price... 1ft was plenty!!! Dave