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Convert to e-fans? Pages: 12

mjlinder on Sat July 01, 2006 12:52 PM User is offlineView users profile

Year: 2001
Make: Ford
Model: F150
Engine Size: 5.4
Refrigerant Type: 134A
Country of Origin: United States

So, we are going to be moving to Phoenix in a few months. We were there last weekend, and my fan clutch was engaged darn near all the time. Here in SD, I rarely hear/feel it. Let me tell you, when it engages the fan, it really sucks the HP. With the fan engaged all the time, the truck is really sluggish off the line. Also, a couple times on the freeway I could feel/hear the fan kick in. Some guys over on the F150 forums tried to tell me that the fan NEVER engages on the freeway because there is enough air flow. Yeah right. Pull the grade on I8 in Imperial when it is 113* and tell me that the fan isn't going to engage.

Engine temps around town, mid-day, stayed below 208, usually 204-206. On the highway it ran about the same, but pulling a couple of the big hills on the highway it got as high as 218 (but I was pushing it, too). And this was unloaded. Sometimes I'll be pulling my Jeep on a trailer, about 5K lbs total.

So I'm thinking about electric fans. There are a couple dual fan drop-in kits that are rated for something like 5000 or 5500 cfm. I know I am just transferring the load of the fan to the alternator, but I don't think it takes as much HP to generate the power for the efans as it does to drive the stock fan.

So, I'm bringing this to the group here.

E-fans in Phoenix? Good idea? Bad idea? Is 5000cfm going to be enough to adequately cool AND keep the AC working?

Thanks!

Mark

TRB on Sat July 01, 2006 1:51 PM User is offlineView users profile

We have stock Fords running all over town without additional fans. Important to have a full shroud and prefect cooling system when it gets a little warm out. I think its more of a personal choice. You might get a little better performance but is it a must for our climate, no.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

NickD on Sat July 01, 2006 8:13 PM User is offline

The efficiency of your alternator is 50% and that of an electric fan is 70% for a net efficiency of 35% causing about three times the load a directly driven fan would put on the engine moving the same air If your thermostatic controlled clutch fan is kicking on when others aren't, the thermostat is getting hot assuming it is good. You may have airflow problems, SD is very close to MN where the state bird is the mosquitoes not to mention thousands of other insect species that may have found their resting place in your condenser and radiator fins. Have to find another place to bury those insects so you can get some air flow.

mjlinder on Sat July 01, 2006 9:08 PM User is offlineView users profile

Nick - not quite sure I was following you on that one. And SD isn't South Dakota, sorry - it is San Diego. I'm not having any cooling problems - everything ran just fine. My question was whether or not efans would effectively cool the truck. The reason I'm asking is because the stock fan does put such a load on the engine. I have heard, and I don't know how true it is, that it takes an additional 1HP to generate 30amps out of the alternator, so with 2 fans it would only be a 2hp load, whereas the stock fan eats 15+hp. I'm sure those numbers have been exaggerated to make the efans look better. That, and most of the guys on the F150 forums who have gone to efans have reported a 1-2mpg average increase in mileage.

Add to this, I just found that there is a tech bulletin from Ford regarding sluggish performance in hot temps, and there is a PCM reflash that is available. I think I'll get that done and see what happens and go from there. I'll be back in PHX in a couple weeks so I'll know if the reflash makes a difference.

Edited: Sat July 01, 2006 at 9:19 PM by mjlinder

k5guy on Sat July 01, 2006 10:39 PM User is offline

The answer to your question is that efans do work. However, the stock fans do too. Nick is talking about energy usage, and that the stock may use less energy. It's your call.... both work.

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bohica2xo on Sun July 02, 2006 4:22 AM User is offline

Congratulations. You have a five year old fan clutch that is still working perfectly Be very glad that it is.

Check your air path, and clean the condensor carefully to maximize cooling capacity before you move to PHX. The "sluggishness" is not all fan horsepower - at high ambients the PCM can make adjustments to several parameters, limiting output to avoid detonation. Poor airflow through the condensor & radiator can cause the underhood air temp to rise dramatically.

Fan blade design, and absorbed horsepower is all well developed science. You can only get so many pounds of air per minute for a given shaft horsepower input. If your engine driven fan is soaking up 10 horsepower, then you will need a 10 horsepower electric fan drive to match it's mass flow. At 13.6 volts, that willl be a 600+ amp load. If an electric fan existed that would move the same volume of air, under the same conditions - using 90% LESS power, it would have come on the truck as standard equipment. With the CAFE requirements that the manufacturers face, they would install that fan, regardless of cost - but it does not exist.

Plenty of aftermarket fan makers list some sort of CFM rating, taken under ideal conditions. The fan in your F150 has a restriction on the inlet, and a restriction on the outlet. Under the same conditions, the electric fan does not do so well. Ford tested that fan assembly at the Yucca Proving grounds, in southern AZ. They test while towing, they test while rock crawling. Take advantage of all of that research. You would have to be out of your mind to tow a 5,000 pound trailer without the mechanical fan.

The fox body crowd loves electric fans. Lots of bragging about how well they work. Many of those modified cars see only a few seconds of high engine loads per hour. The electric fans work ok for this, since the airflow is slightly higher than idle airflow with the OEM fan. "it never overheats" - uh huh. Put a trailer on that car, and drive it up a grade...


.



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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

NickD on Sun July 02, 2006 6:55 AM User is offline

Whoever told you 30 amperes per HP is pretty close at 12V, that's 360 watts that is roughly half of 746 watts per HP for the 50% efficiency of an alternator. But running at 14.5 volts the setpoint of your regulator, 26 amps per HP is a closer figure. So running an electric will take twice the engine energy on this basis alone, but you still have to deal with the inefficiency of the fan motor so no matter how you slice the mustard, and electric fan will consume about three times the energy over a directly driven fan.

Whoever told you your stock engine driven fan consumes 15+ HP probably just purchased a 15+ HP advertised air compressor that can run off a 20 ampere 120VAC circuit on a 100' 16 AWG extension cord.

For years Ford has used the same 3.8L in both the Taurus and T-Bird vehicles, where the Taurus is a FWD vehicle with an electric fan and the T-Bird a RWD vehicle with an engine driven fan. The Taurus didn't kick the fan on until the block temperature exceeded 205*F so that engine would thermal cycle between 195 to 230*F constantly in traffic causing HG failure due to thermal stress on the aluminum heads as they saved a couple of bucks by not using a radiator sensor like Honda did that would kick on the fan when the radiator temperature hit 160*F so the Honda would run at a constant 195*F. The T-Bird didn't have this problem as it had an engine driven fan where the engine would also run at a constant 195*F, so, so much for the Ford electric fans with very cheap and poor fan controls HG failure in the same 3.8L T-birds was rare, but extremely common in the Continental/Taurus counterparts using the same engine.

An engine requires the greatest fan cooling at idle or close to idle speeds when the alternator is least capable of producing this extra current, alternator life typically was 1/3 the life of their RWD direct engine drive fan counterpoints.

The HP a fan uses is directly related to the amount of air it moves, take any size fan and run it in a vacuum and the effective HP consumed is zero, any restrictions in the air flow system have the same effect to lower the HP the fan uses as the fan ain't working, just spinning.

The bottom line is that an electric fan uses three times the energy as a directly driven fan and if you are talking about getting better fuel economy, either stick with your mechanical or if you have an electric, think about a flexible engine driven shaft to run that blade. This is not BS, but basic energy facts.

mjlinder on Sun July 02, 2006 11:27 AM User is offlineView users profile

Thanks for the replies. This is great information and this is EXACTLY why I asked here and questioned the numbers that others were throwing around.

As I stated in my last post, I did find that there is a factory TSB related to sluggish performance in hot weather, so I was probably experiencing that as my power loss and not so much the fan - the fan just happened to be on because it was HOT! I have also been monitoring my intake air temp (thanks to my new Edge programmer) over the past few days and I noticed that they were 25-35* above ambient (so in Phoenix at 110* my IAT would have been 140-ish - ugh!!). The DSPO had removed some pieces around the air box, for better power I suppose, and it appears to have been sucking air from under the hood. I fabbed up some pieces yesterday to get it to pull air from where it was designed to, and my IAT is now 2-3* above ambient.

So, a known drivability issue (directly related to IAT, as stated in the TSB) combined with abnormally high IAT due to the "modifications" and I think I really found my problems. The efan subject will get tabled for a while now. I'll get my PCM reflashed this week and I'll be in Phx next week, so we'll see how much different things are.

Edited: Sun July 02, 2006 at 11:37 AM by mjlinder

NickD on Mon July 03, 2006 8:53 AM User is offline

On older vehicles where the fan clutch was an option, did dump that and put in a fixed fan, talk about improved performance in both the AC and a much longer lasting underhood, those excess temperatures take a toll on all that rubber in drying out, getting brittle, and breaking. Todays vehicles add lots of plastic that even gives more problems. Was always touchy on fuel economy, kind of a switch in performance from my quarter mile days where a two buck plastic trophy was the reward for tearing out a rear end. Ha, and if you really wanted to make the crowd happy, would blow an engine or better yet, kill yourself. So much for that. Fixed fan didn't make a bit of difference in fuel economy, but man, did that AC blow cold, even when pulling a heavy 20 foot wood boat.

As a pilot, really got an appreciation for that big fan up front, you don't dare push the stick forward, even a tad without backing off the throttle, can red line an engine in a hurry. Never believed in this crap about all the HP a clutchless fan uses when cruising along at 70 mph. While the fan is spinning, getting lots of help from that 70 mph wind. In traffic, you really need that fan.

Would think about changing your thermostat, 208*F sounds a bit too hot. Can test these with a pan of water on your range and a cooking thermometer to learn what temperature the valve cracks open at, be surprised as to how far off some of these are and much quicker than testing it in the vehicle.

Don't like these FWD cars that use the coolant thermistor for fan control, did convert some by adding a radiator sensor to kick in the fan when the mid of the radiator hit 160*F, not an original idea of mine, but stolen from Honda and Toyotas, that kept engine temperature exactly at 195*F rather than have it cycle between 205-230*F, crazy. Didn't do my DeVille yet, too complicated with two fans with two speeds each, just don't idle it, and only use it on the highway. My Cavalier copied the Japs, good idea, GM.

MrBillPro on Mon July 03, 2006 10:10 AM User is offlineView users profile

So do we have a verdict? are the e-fans a good thing or bad I was thinking about using one in series with my clutch fan and building a computer for my truck that would know when I was in traffic and call for the e-fan.

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Don't take life seriously... Its not permanent.

NickD on Mon July 03, 2006 10:28 AM User is offline

Ha, I would opt for a fixed clutchless fan, if you get one large enough, could dump your AT and drivetrain as well. Is nice in an airplane, really didn't care if the runway was glare ice, just hit the throttle and it would go, none of that wheel spinning crap.

wmchurch on Mon July 10, 2006 4:41 PM User is offline

FYI, Jeep started with Electric fans in their 1998 Grand Cherokees w/ 5.9L V8, and the newer WKs (and WJs maybe) come with electric fans. I've not done the calculations, but it seems to me they found it to be more efficient to use an electric fan on the 5.9L V8 in lieu of the clutch fans (which was standard on the 5.2L models). For those that don't know, the engine compartment in the Grand Cherokee is a bit cramped for a 5.2L V8, let alone a 5.9L V8 (same outside dimensions, but more heat).

Electric fans are mostly suited for low RPM use (rock crawling or trail riding) and for deep water crossing (being able to shut the fan off during a crossing). In most cases, when going down the road at 70 MPH I don't think any fan can keep up with the natural air.

Using a pusher fan in concert with a clutch fan is not a bad idea. Mercedes does this and it makes a huge difference, theirs is tied in with either a pressure or temp switch on the condenser I believe. You can find fan controllers that will set high and low speeds based on temperature.

Edited: Mon July 10, 2006 at 4:45 PM by wmchurch

MrBillPro on Mon July 10, 2006 7:52 PM User is offlineView users profile

Quote
Originally posted by: wmchurch
FYI,
Using a pusher fan in concert with a clutch fan is not a bad idea. Mercedes does this and it makes a huge difference, theirs is tied in with either a pressure or temp switch on the condenser I believe. You can find fan controllers that will set high and low speeds based on temperature.

Well, if I ever get some time I will probably try it anyway and like Chick said place it in a certain location for the best a/c cooling that is what I am looking for anyway, truck runs cool but I was just looking to tweak the a/c cooling since I already had the fan, but being in the Commercial and Residential A/C business in Houston I am beginning to wonder if I will have to wait until Sept. to do it, we have just been swamped, speaking of swamped I looked like I had been swimming in one when I got in today man it's hot and humid in Houston.

By the way I wonder what amp relay you might use on a 14" electric fan I forgot to take the relay off when I sold the El Camino but I did take off the electric fan.

-------------------------
Don't take life seriously... Its not permanent.

chris142 on Tue July 11, 2006 10:57 PM User is offline

The aftermarket electric fans are nothing but trouble. 2 of them will not cool your engine and you will have problems. Lots of guys use ford Taurus fans, they use something like 35 amps running and much more to start the motor.

Remember a few years back Ford was having cars burn down because of the high Alternator Amps being drawn from the electric fans?

Jeep does use electric fans on some Cherokee's and Libertys. But if you get the towing package you get a fan and clutch plus the electric fans.

Flex fans work for about 2 weeks then the blades flatten out and your back to overheating again.

TRB on Tue July 11, 2006 11:27 PM User is offlineView users profile

Quote
Originally posted by: chris142
The aftermarket electric fans are nothing but trouble. 2 of them will not cool your engine and you will have problems.


There are cheap fans on the market but there also are some the will move a heck of a lot of air. All depends on the quality of the fan. But most buy by price these days!


-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Travis on Wed July 12, 2006 3:10 AM User is offlineView users profile



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1993.5 Single Turbo Toyota Supra 714RWHP
1985 Suburban
1997 Pontiac Grand Prix GTP

Travis on Wed July 12, 2006 3:12 AM User is offlineView users profile

For PHX, I'd change to a cooler thermostat and mix the water 70/30 with a bottle of Water Wetter...I lived in Tucson and this really helped.

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1993.5 Single Turbo Toyota Supra 714RWHP
1985 Suburban
1997 Pontiac Grand Prix GTP

NickD on Wed July 12, 2006 8:17 AM User is offline

So after reading these posts, put my Cavalier in 1st gear and was revving up to 4,500 RPM at 20 mph, this ain't exactly a geared down vehicle like a 4WD where 4,500 would maybe hit 4 mph tops. Meaning the engine is running fast enough to spin a fan.

As I said before, with my own experimentation, never have been able to simulate all this BS about directly driven fixed engine fans using all this energy, when the vehicle is moving slow, you gotta have all the fan you can get, and when it's running fast, that fan is practically free wheeling. For me, with engine fans, flex and clutch fans have been nothing but problems and very expensive problems at that. Still wonder what good that hard piece of rubber that gets brittle and falls apart after a couple of years they are putting in damper pulleys now. Damper pulleys were never a problem, now they are a 250 buck problem and that doesn't include labor. So I am on the subject, this damper pulley turn the fan or the alternator.

Speaking about the alternator that drives the electric fan, the stator for years was sandwiched between the outer covers and exposed, and easy to remove. Now due to some weird EMI rating that really doesn't exists because it is simple enough to damper all the transient out, the stator is pressed into a totally enclosed rear frame. The aluminum is loaded with eddy currents causing the alternator to run much hotter, already way too hot, and forget about repairing it, dissimilar metals again solidly corrodes the stator to the frame, easy to press something into a deadend space, but try and get it out.

What I would like to see is an aftermarket fixed fan for direct driven fan that is fixed and can handle the speeds like the old ones could, and some kind of flex cable or gear driven fan for FWD vehicles, this is what makes sense. No matter how you cut the mustard, takes three times the energy to run an electric fan than a direct driven fan.

Practically any owners manual tells you not to idle your vehicle for any extended time, but wonder if the guys that wrote this, (because they have to due to the design of these vehicles), ever took a car on today's traffic jammed streets.

mjlinder on Thu July 13, 2006 3:52 AM User is offlineView users profile

Quote
Originally posted by: wmchurch

In most cases, when going down the road at 70 MPH I don't think any fan can keep up with the natural air.


You know, I keep hearing that and real world experience just tells me it isn't true. Just got back from another trip to Phx today. Coming over some of the mountains in 110+ degree temps, I would watch my coolant temp rise slowly, and when it got hot enough I heard that fan engage, and coolant temps went back down and the fan disengaged. I would think, and someone correct me if I'm wrong, that the fan is therefore pulling MORE air through the radiator than what is passing through due to the vehicle speed.

Some of the guys on one of the diesel boards are reporting that the fan on the Duramax Diesel will pull 10Kcfm at 3Krpm.

Mark

NickD on Thu July 13, 2006 7:30 AM User is offline

Well, you know a stalled fan blocks air, if it free wheels with air pressure, redirects the air to the side. If you flew a twin and killed one of the engines, even though those props like tiny compared to the rest of the plane, that stalled engine is like that wing hitting a brick wall and you are fighting crazy with the controls to prevent going into a spin while trying to feather that prop.

If you are flying say a Cessna 172 cruising at 120 mph and burning about 8 gallons of gas per hour, that's 15 mpg on the ground in still air. With a 40 mph tailwind, your ground speed is 160 mph, making darn good time and getting 20 mpg doing it. But with a 40 mph headwind, only going 80 mph and only getting 10 mpg.

Was the same with my old motorhome with a 30 mph tail wind doing 55 mph, would get 15 mpg, but change that to a headwind, would drop to 6 mpg.

So while they are playing games with a tiny fan buried deep inside the vehicle, nature is in control, too badly they can't put a switch on for wind speed or direction.

Ha, on my present motorhome there is a large AT cooler in front with even a larger engine oil cooler behind that, followed by an even larger condenser, followed by an even larger radiator before the fan even see the air. All these fins are a restriction, parallel to the wind flow or not.

People thing by putting their hand over the nozzle of a vacuum cleaner they are straining the motor, reverse is true if the cleaner is plugged into a wattmeter first. Input power goes way down when plugging the nozzle, if an AC motor was used, the cleaner would become dead quite, but they use a universal brush type motor whose speed is inversely proportional to load. So killing the load with your hand revs the motor up and that is what you are hearing, but the input power drops down to practically nothing. Not doing any work.

Course don't hold your hand too long as todays vacuum cleaners so they can write 12 amps on the case generate over three times the heat as mechanical power, more of a hair dryer than a vacuum cleaner and stopping that badly needed air flow can burn up the motor.

Has anyone seen any charts or other forms of proof on the benefits of electric fans considering all factors? I haven't and looked, as far as I am concerned, just more marketing BS.

JeremyB on Mon July 17, 2006 12:29 PM User is offline

Quote
Originally posted by: NickD
For years Ford has used the same 3.8L in both the Taurus and T-Bird vehicles, where the Taurus is a FWD vehicle with an electric fan and the T-Bird a RWD vehicle with an engine driven fan. The Taurus didn't kick the fan on until the block temperature exceeded 205*F so that engine would thermal cycle between 195 to 230*F constantly in traffic causing HG failure due to thermal stress on the aluminum heads as they saved a couple of bucks by not using a radiator sensor like Honda did that would kick on the fan when the radiator temperature hit 160*F so the Honda would run at a constant 195*F. The T-Bird didn't have this problem as it had an engine driven fan where the engine would also run at a constant 195*F, so, so much for the Ford electric fans with very cheap and poor fan controls HG failure in the same 3.8L T-birds was rare, but extremely common in the Continental/Taurus counterparts using the same engine.
Uh, head gasket failures are actually quite common in Thunderbird/Cougars with non S/C 3.8s.



Edited: Mon July 17, 2006 at 12:37 PM by JeremyB

NickD on Mon July 17, 2006 6:36 PM User is offline

Just never ran into anyone with this era of bird or cat that had HG problems and many were hitting the 200K mile mark without engine nor transmission problems. The extra heat of the electric fan models may have contributed to AXOD failure and the constant temperature to the HG failure problems.

Not doubting your word, just haven't ran into that person yet. One thing for sure with the 3.8L engines, you are limited to zero major overheating conditions, the heads just can't take even the slightest bid of punishment without rebelling.

Was in a Supra club for a short time, didn't fit in as my interest was in preserving this fine automobile where everyone elses interest lied in pounding their cars to death.

They asked me if I had HG problems as the Supra is known for this, never heard about that was my reply, but turned around and asked if they were playing with the waste gate valve, defeating it's function does two things, boosts the intake manifold pressure by another 6-8 psi that causes the second thing, blowing the HG.

Guess who were playing with the waste gate valve? None of these guys felt comfortable removing the head to repair their blown HG where they should have installed a modified gasket first. But only could cry to their dealer or between themselves that their HG blew.

JeremyB on Mon July 17, 2006 6:59 PM User is offline

Well, I am only familiar with Tbirds/Cougars...and not Tauri.
The only years Ford extended the warranty for 3.8L head gaskets was 1994/1995. The MN-12 Tbird/Cougar had electric fans starting in '94 and continued until '97. '89-'93 MN-12s had mechanical fans. All MN-12 3.8s had head gasket issues. The general feeling on the MN-12 message boards is not if, but when your 3.8 will blow a HG. '96-'97 MN-12s were a little less prone to blowing HGs. Fox Tbird/Cougar ('83-'88) 3.8s also had HG problems.
'99+ 3.8s use MLS HGs, all previous cars use graphite HGs.


Edited: Mon July 17, 2006 at 7:01 PM by JeremyB

JCS4640 on Wed August 30, 2006 12:40 PM User is offlineView users profile

I have 4 elc. fans on my hot rod ,2 pull and 2 push w/ alum raid hwy is fine a/c works great -in town not to good in 80 and above, o i do not use water in raid I use evens coolant

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JCS4640

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