Can anybody tell me what cfm my stock fan provides to cool my engine so I can look for a sufficient electric conversion?

 

From all the reading I have done their is not an electric fan capable of cooling our trucks under the conditions that they operate under..

 

I need to know what cfm the stock fan provides because I sound some I think might work and if not I might engineer one myself, but I need to know what cfm is needed...

 

I seem to remember the stock fan is in the 20,000 CFM range.

 

In my 03 Dodge with the 5.9L magnum, I was running the well known Ford Taurus E-fan on low. It did better than the OEM clutch fan.

To give a visual:
If you picture the temp gauge more like a fuel gauge


(E, 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, F)


My truck while running the clutch fan would operate at 3/8... When pulling my boat or camper, it would run warmer. Averaging 1/2 to 5/8.
A friend of mine strongly recommended the Taurus fan. So I went to the local pick and pull (junk yard) and pulled one. Went to the part store and bought a Hayden adjustable controller. The Taurus fan is a dual fan, with dual leads. The controller is for a single fan. I went that route because supposedly the low range on the fan was more than enough. I figured that if I needed more, I would run a manual switch set up for the high end. I did a lot of driving around, idling and other tests before ever trusting it towing. First time towing I towed the boat out to my buddies house just to test. It's only about 10 miles, and flat. The temp gauge didn't move. I was feeling better. So we took the boat to one of the local lakes, and it's about 20 miles away, and there are some good rolling hills that I would normally see a little variation in temp. Gauge didn't budge. Next time we took the boat to our favorite spot that normally had the gauge passing the 1/2 mark. Again...no change. The final test was taking the camper up over the mountain that normally had my truck sweatin quite a bit. Low and behold, it held temperature! The longest tow I did was from Colorado to NW Wyoming pulling a 14' flatbed loaded with a 1975 Corvette. Never had any problems.

I never did wire up the high speed on the fan. Always used the low. I plan on doing the same for my 'new' 1999 I just picked up. And I will go through the same tests and report.

Parts list / Cost?
93 Taurus with the 3.8L - $15
Hayden controller # 733647 from Advanced Auto Parts - $35
Fan mount kit from Autozone - $15
Total=$65 and some wrench time.

As for performance / economy? I'm not going to sit here and claim hp gains. But I do understand parasitic loss, and it's no different. My truck went from averaging 10 mpg regular driving and 7 towing to getting 14 average and 10 towing. To me that is 'claim'.
Even though this truck is more powerful and shouldn't have as hard of a time towing my gear, I intend to do the same thing again, but this time use Hayden's two speed model (3654).

Sorry for being long winded. Hope this helps.

 

i am sorry, but that is simply absurd.
whoever told you that was making something up off the top of their head.

to the OP,
what are you trying to accomplish?
if you want faster warm ups, I have my doubts that an E-Fan will accomplish that.
in a properly operating vehicle, the thermostat is completely closed until around 175 degrees and is only partially open until around 190-195 degrees. that is with a 180 degree t'stat.

you could have the fan run at full blast and it would not change the fact that no water is flowing though the radiator until the radiator water is fully up to temperature.

the benefit to an electric fan is increased fuel economy (possibly as high as 5%) and more power (sometimes as high as 15hp without a flex-fan or clutch fan)

there are two reasons you shouldnt worry about this in your truck.
1) Fuel economy:
for there to be a boost in economy, you need to run the engine a bit hotter. this is at the cost of emissions (see rant at bottom)
in a truck with the intent of towing, you run a fine line between getting better fuel economy and overheating because you put in a different thermostat.
if you dont plan on ever towing very much, then go for it.

2) More Power:
for the same reason that a hotter temperature promotes better fuel economy, a lower temperature will allow you to make more power, advance your timing more, and add more fuel to your mix. this of course will negatively impact your emissions and economy.
the main reason however for people saying that an electric fan gives you more power is that back when electric fans were new, the alternative was (quite often) a solid mounted fan with no clutch and no flex in the fan. these cars usually were old and had 2 or 3 speed transmissions and big rear gears.
as you can imagine driving down the highway at 3000 rpm with the fan pushing 3000rpm worth of air at full speed was BAD for power and BAD for economy.

nowadays, cars spin about half that rpm and the fans are on clutches so that they spin about 75% of the engine speed.
in other words, the amount of power being sucked down by your fan is MUCH less than 15 hp. probably more like 4-5.



will you really notice 4-5hp?
will you be more pissed if your truck overheats when you are towing up hill?

if you want to put together an electric fan setup, go for it!
i can give you pointers and help you wire it in, but i just want to make sure that you have the right idea about WHY the truck is the way it is.
if you are building a drag racer where the fan will not be on when you are racing, then it makes a lot of sense.



just so you know,
i had a car with a 3 position switch for the electric fan.
ON-OFF-AUTO
i normally left it in auto, but when i wanted that last bit to race, i switched it to ON while i was lining up, OFF when the hammer dropped, and back to ON until i was ready to race again.




RANT FROM ABOVE:
i am sick and tired of politicians confusing the QUALITY of emissions and the QUANTITY of emissions.
we all remember the dreaded EGRs of the 80's that we ripped off and gained power...
a modern example exists in most newer sports cars, like the mustang.
it has a feature where when you lift off the gas suddenly, the computer holds your previous throttle position for about a second in case you decide that you really didn't mean to lift off. then if you dont apply throttle again, it slowly backs off to idle.

the idea is that if you reduce any sudden changes in airflow, you dont have any sudden spikes in emissions when the computer can't react fast enough to the changing airflow.

the MAJOR problem with this is that it NOTICEABLY impacts shifting in a manual transmission, and makes the automatic versions feel like they are always pulling you forward, even when you are on the brakes.
not only that, but while the computer is holding the throttle for you, the QUANTITY (Amount) of exhaust produced is much higher than if you were to return to idle.
the QUALITY of the exhaust is cleaner, but since there is so much more of it, you end up polluting more than if you had simply left this whole "AUTOMATIC GAS PEDAL" thing off in the first place.

there are countless examples of this kind of thinking in the automotive industry and it really gets old
/rant

 

oh, one more thing.

according to the laws of thermodynamics, it doesnt matter how many CFM your fan pushes as long as the air moving through the radiator is still cooler than the radiator when it is done going through the radiator.

picture it like this:
________180
==> 70* ||| ==> 150*
==> 70* ||| ==> 150*
==> 70* ||| ==> 150*

as long as the air leaving the radiator is still cooler than the radiator (180*), you have enough CFM.
i could figure out exactly how much air is required given the radiator size and temperature of ambient air, humidity, engine temp, altitude, barometric pressure, ect... but i wont.
2000-4000 CFM should absolutely be more than enough.

most cars use around somewhere 600 CFM if i remember correctly.

in my Camaro, i had 2000-2200 CFM, and with the fan in the ON position, the thermostat would partially close and the engine would hold 165* (160 thermostat)
this was even during the hottest summers when i was driving like a madman

 

So your saying you gained 4 miles to the gallon by ditching the factory fan , fascinating......

 

I'm saying that I'm one of those guys that regardless of how accurate that people claim that the on board computer is/isn't for MPG read out, I use it as a base and I watch it all the time. Those were the number differences I saw. Now if the computer is off, so be it. But the main point is that it did increase economy, while my $55~ investment vs some of the multi-hundred dollar set up's I've been seeing was keeping my truck plenty cool on it's low setting.

 

Just curious how you are monitoring your coolant temps , SG2 ??

 

No, I was merely using the factory gauge. Never got around to putting in a pillar with additional gauges.

 

The factory fan is 10k cfm. Sounds absurd, but that's what it is. I've read most of the 7.3L fan kits can be modded to fit pretty easily. That's one thing I'd like to do, I hate the stock fan and rear shroud setup when working on the engine.

 

Wow, there are a ton of misconceptions and just plain BS on this thread.

The reason you would want to use an electric fan on a Super Duty is to replace the stock fan, hopefully for an increase in mileage. Theoretically, you do not need a fan when the engine is cold, or you are running down the road at a decent speed. Never mind coolant speed or the theory of relativity. It's all a red herring.

Back in 1980 we worked on a buddy's 1/2 ton Dodge van. We put in an "RV" cam, dual exhaust, 2 electric fans and a cooler thermostat. With some tuning, we got his mileage from around 15 MPG to almost 20 MPG.

 

The OP didn't even say what engine he was asking about, that I saw. Knowing that would make a big difference in the answer.

This is mostly nonsense. If this were true, Ford wouldn't put a 10k CFM fan on the 6.0L. They are going to put the least manufacturing expense into the design of the vehicle.

If you're speaking of the 6.0L, it's not a Camaro, or a Dodge, or a motor home. It's a 6.0L diesel. I'm pretty sure Ford designed the cooling system the way they did for a reason. And I doubt any electric fan is going to cut it.

Also keep in mind, speaking of the 6.0L, that the fan clutch is computer controlled. While the fan will always spin a little due to bearing friction, the computer can command the fan to 0% and the HP loss to the fan will be negligible.

 

See this website. It claims 6200 CFM for the fan. It will reduce drag on the engine.

Amazon.com: Flex-a-lite 272 SuperDuty Fan for 98-03 Ford: Automotive