I don't doubt that the fan uses 20 horsepower when it is locked up and you do feel it. I feel the power loss in my big trucks when the fan is on. I know of no electric fan I would trust though, and as far as taking it off in winter, that all depends on how you use your rig. I have had mine come on when it was well below zero.

 

ive filled the overflow tank on my 91 when its was 5 degrees out. removin the fan is NOT somethin i would do. if youre gonna do somethin like take the mechanical fan off, you need to put an electric one on. runnin without a fan is a BAD idea...

and as stated, the little bits here and there add up. next time you go to the dyno, take all your belts off. leave just one on the water pump. take your fan off too. make one pull without a PS, alternator, A/C, or a fan. ill bet you gain at least 50 horses at the rear wheels.

 

i'll take that bet. You think those accessories take 80 hp to drive? Not a chance

 

go to the dyno. report your numbers back to us.

 

when i get my new engine done, id be glad to. although with my engine burning 4 gallons of coolant in 150 miles, my egt's have never been lower. i bet id make a great run. you should see the coolant cloud thats flowing out of my blowby tube too....

 

lmao! im sure thats quite a sight...

 

If you think for a minute, 10 HP off the engine HP before the drive line percentage loss feels like a lot more than 10 HP.

But also remember, converting from a mechanical drive fan to an electric fan just changes which device is sucking the most power from the engine.

Also if you have a stock 65 amp alternator, and a fan that draws 50 amps, you may be in for an alternator upgrade or dead batteries way to often.

My guess when the fan is locked up, 25 HP.
Add in the drive line loss, about 32 HP at the rear axle.
That is a big fan, it moves a lot of air when it is locked up.

 

i have the 100 amp alt dave

 

don't we all have the 100 amp or better alternator?

if you do it right with a monster fan like the taurus fans or the lincon fan someone linked the fan isn't on often enough to be much trouble for the electrical system you just have to make sure the fan don't kick on till after the thermostat is wide open

 

If you use your truck for what it is designed for and not just a commuter, I wouldn't recommend electric fans. They might be fine for just running around town with minimal load, but they will not flow enough air to keep cool when you really start working the engine hard. And, when you factor in the electrical draw on the alternator, how much are you really gaining?

If I'm pulling 10K lbs up a 6 or 7% grade in July, I'm trusting the good old mechanical fan and sacrificing what little mileage gain there may be.

I ran the same Taurus, 2 speed fan in my Bronco several years ago and they had a hard time keeping it cool at slow speeds if the temp was above 85 deg.

Jason

 

I make it part of my winter routine to drive with the fan removed. Never had an overheating event and I started getting too hot before the truck did (AC doesn't work unless you have a fan when sitting in traffic). The last day I did have it running a little warm while moving a trailer in the yard. By then it was already shorts & T shirt weather.

Where did I gain? mainly in the short trip department. The fan I noticed tends to eat a bit more power when the engine is still warming up and its very noticable when it lets go (about 1/2 a mile before the cold advance kicks off).

Highway miles didn't seem to return much gain and recently when I was getting 18-18.8 MPG while towing between 55 and 60 MPH, I added the fan back half way through and it made no difference.......well there might have been a 0.4 MPG drop but thats well within the margin of error.

One big advantage of an electric fan is you can have it running when the engine is at idle for high power cooling even at low engine speed. If nothing else you can have the air conditioning working better in traffic.

I would like to add an electric fan setup out of one of those big V8 lincoln or ford cars but I probably will never make the time for it.

 

Whats shorts & t shirt weather ... It was +72F here today, I still have my thermal plaid on and was moving furniture all day, my buddy wears shorts and T's year round, even when it's -21F ... !

-Enjoy
fh : )_~

 

i am the former of the two descripted...

 

Stock alternators, some of which were as low as 56 amps in the early model IDI just won't support electric fan power requirements.

Horton does make an electro magnetic fan clutch that will work on the IDI by replacing the stock fan clutch and still using the stock fan.

But at 700+ dollars it is a bit expensive.

Horton EC 450 is the base part number, and right now I don't know where my arrangement number that fits the IDI is.

 

I wonder how hard it would be to make one out of a A/C clutch to fit the stock fan.