I am thinking about putting electric fans in my truck to help with fuel mileage and I was wondering how any of you who have done like the kit you are running/have any recommendations on kits to use and what you paid for yours

 

Yup.

Lincoln Mark VIII two-speed fan, switched by Volvo relays, controlled by an Edelbrock EFI ECU... links in the tech info compilation sticky.

The fan was $35 and the relays $8 or so.

 

Controllers can get elaborate, but I've used a simple cheap adjustable ones, with a probe that extends into the radiator hose, with a single, big fan, center of stock shroud. No problems, ran one to this day, 16 yrs old, even ran A/C for a while, no problems.
Even ran simple $20 thermostats you zip tie to the radiator hose.
Just depends on how much you want to invest.

If you go the basic route, wire a relay into the fuse block accessories, from thermostat, so when you crank the engine, the fan goes off, so all power gets sent to the starter.

If you can swing it, there are nice controllers out there thatll really fine tune the fan function.

 

Stay away from the probe-type sensor. They are grossly inaccurate.

.. before upgrading to electric fan(s), strongly consider upgrading your alternator ... 90 amps minimum. Many a FTE'ers have done the 130-amp 3G alternator retrofit.. some for as little as $30.


Electric Fans/Cooling Upgrades
Ford Muscle: Lincoln Mark VIII Retrofit
Fordification Thread: Lincoln Mark VIII/T-bird Two-Speed Fan Installation
Pro-Touring.com Thread: Mark VIII fan & SPAL Controller
Hollister Road Electric Fan Components
The Fan Man - Electric Fans & Controllers
Nasty Z28 Thread: Budget Dual Electric Fan Controller Set Up
FTE Thread: akforceten's 1972 F250
Centech Fan Controllers

 

Bigred, May I ask what do you hope to achieve? Have you ever heard the term peeing into the wind? You might get 1/4-1/2 mpg best.


John

 

My probe thermostats been accurate enough for 16 yrs. It's a simple design, thats used in many other non automotive apps, whose function revolves around temperature sensitivity.

I wouldn't do the efan conversion so much for mileage, as less resistance to the engine, every little bit helps.

 

The basics for get a little better mileage is a bunch of little things that all add up.
Theirs not one really big fix that will give you instant super MPG using the stock oem engine.
One way is by unrestricted the air flow into a engine and out with correct carb jetting.
Reduce engine drag can be of many things & ways.

If it produces any increase in mileage then that's a good thing Right.

It's better to have saved a little gas then too have it taken away any mileage.

The way, I see it when a gallon of reg. gas has gotten up to $5.58 per gal.
like it has happen a few times here in Shaky Sunny N. Calif.

It's either by doing one or the other, stop driving these old classics or milk out as much MPG as you can in these high prices time.

Plus we know we've at least made an effort trying to get any added mileage out of these gas gobblers fe's trucks.
My 0.2
Orich

 

Lincoln Mark VIII two-speed fan, switched by Volvo relays, with BMW 2 temp fan switch mounted in thermostat housing. I have a thread on here showing details .

 

Here are some pictures of the Volvo relay with the BMW switch setup.

 

The main benefit with an electric fan is it spends more of its time in the off-state than in the on-state. Above 25 MPH, you don't need a cooling fan --as long as you don't have some other problems. The ram effect of the vehicle's forward motion will force more air through the radiator than any cooling fan (mechanical or electric) can draw through it so, at that point, a cooling fan spinning around would pretty much be a useless waste of motion.

An electric fan won't free up copious amounts of engine horsepower nor will it gain you huge amounts of increased fuel mileage. It will gain you some of both when it's not running but, not hugely so.

Electric fans don't come for free. It's a mechanical, to electrical, back to mechanical device. The first mechanical portion is a belt has to turn the alternator to generate the power to run the fan motor by. The electrical power is sent to the fan motor through wiring and relays to spin the electric fan motor. The electric motor has to turn a mechanical shaft to spin a mechanical fan blade. None of these processes are at 100% effeciency. They all translate to both mechanical and electrical losses in the system.

As long as the electric fan(s) isn't running, the fan isn't putting a load on the alternator (other things might be but the fan isn't). The instant the fan kicks on, there's an immediate in-rush of current placed on the alternator. This is generally on the order of around 35 amps or more and tapers off to around 8-10 amps once the fan gets up to speed.

This places a load on the alternator. As the load increases on the alternator, the alternator's pulley/shaft becomes more resistant to turning. This, in turn, places a greater load on the engine and now it has to work harder to try and keep the alternator spinning. --more load on the engine means it has to burn more fuel to try and maintain the same output.

Some claims are that an electric fan will free up something on the order of 17 hp. In reality, you might get .5 hp. If you're really lucky, maybe 1 hp.

1 hp equals 745.69 Watts of power.

So, 17HP = 12,676.89 Watts

Watts = Voltage x Current so, 12,676.89W would translate to 1,056 Amps.

If the electric fan had to do the same work as the mechanical fan it replaced to net a 17 hp gain, the alternator would have to be capable of generating 1,056 amps, just for the fan alone.

It's obvious to see your high output Ford 3G 130 amp alternator wouldn't last long at trying to produce 1,056 amps just to run the electric fan (and that's without powering anything else on the vehicle). It's also easy to see the 17 hp increase claim is grossly exaggerated.

Now, I'm pro electric fans but, I'm not under any disillusionment that installing an electric fan will be the magic bullet to unleash huge amounts of horse power from the engine or, that it will greatly increase its fuel mileage as a result of installing it.

 

Easier to put a clutch fan on it?

I have twin fans on my '69. One is on a temp switch I installed in the thermostat housing(just a std OEM 180* thermo switch), running a relay to turn on one fan. The other fan is on a manual switch on the dash, a "just in case" thing. Never need it, the one fan barely runs for the most part.

I only put the electric fans on it AFTER the stock fan blew a blade and creased my hood! Ya, day late dollar short. Luckily it was only idling, but it still put a 2" lump in my hood.

 

Ok yea back in the day, I remember that there was a few guys all looking at the engine as all of us do when a fan blade let loose hit one guys in the head while the owner was working the throttle gunning the engine. And yea that guys friend died form his injury.

I had just gotten in to the back seat of my brothers friend old 46 Pontiac when he started the engine with his foot haft way on the gas pedal giving it a lot of rpm's when we all heard a loud Bang. Looking down that long hood was now a 4" starting of what looked like a louver. My brothers friend was one of those guys who like to crank up the rpm's when starting a vehicle, I guess he thought it was the thing to do.

Most guys never inspect the condition of the fan blades or it's hub for cracks or looseness. The dangers of the blade coming loose has stuck in my head and always think about the earlier days when that guy died from that blade hinting him in the head.
Anytime, I'm around an open hood with the engine running.

This should be a heads up to remember the dangers of a fan blades.

Orich

 

Orich, I was a Sgt driving a deuce and a half(built in 1952) once and we had been waiting (and idling) for at least 3 hours for the order to move out while stationed in Germany. I was in the S-2 truck and when the battalion got the green light, I was the next to the last truck to move. Just as I let the clutch out, I heard a BANG and steam went everywhere. The blade went through the raidiator and was stuck into the round, yellow colored, vechicle weight marker. I got a life long lesson on safety that day. Near the end of that field trip we had a guy killed by a fan blade from a 30KW generator. All rad. fans were inspected after that. I always stayed out of a direct path of those blades after that.

 

Ah yes Flash-backs are sometime a good reminders to dangers an safety as to where one put his body or face..

Oh yes those ol Army trucks were the days of great learnings one of them was learning the knack of slamming those spilt shifts in the 5 ton multiple fuels. Cargo 5 Ton 6x6 M54 if .....IIRC

And the P/S in those old things was no lunch in the park.
Orich
going up a steep Mtn. Past

 

I once had a '72 on which I had converted the factory A/C from R12 to R134a. Everyone knows the design of these old units will simply not cool as well. I installed dual electric fans only to increase air flow over the condenser at low engine rpm (i.e. sitting at a red light). Like many have said, claims of increased HP and fuel mileage are well overrated. Without the A/C issue, I'd never convert.