I was thinking what all i can do to improve fuel economy, and I thought about an electric fan . How hard is it to change over , and will it be a good addition ? It is nothing i will do right off, but if a good idea, then i will start doing research .
Thanks for all replies
Dave

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81 Dodge D150
It looked easier in the book .

I have not done this yet, but I imagine you will get better mileage, unless with the extra horsepower gain switching from a mechanical fan to electric, you stomp the gas pedal more, then your gas mileage will go down.
I wanted to go to an electric fan, but with the single fan blade, the clearance is not really there, I don't want to clear by 1/4" only. However if you go with 2 smaller fans, like 2 nine inch fan as oppose to a single 16 inch fan you will get better clearance.
I wanted to put in a clutch fan, bought 3 of them, wouldn't clean the fan pulley.
I will look into the fan issue a little later, I think I am going to go with 2 smaller fans...Just my thoughts.....Jerry

If you are looking at putting an electric fan on the 81 D-150,,

for fuel milage,, it certainly can't hurt, the biggest difference that I noticed after changing to an electric fan on my 83 D-150,, was a reduction in noise from the engine bay, at idle and low speed,, when the fan is not on.

if you are handy with wiring, the electric fans from mid 90's caravans are plentyfull at the pull aparts, cheap, fit in a D-150 like they were made for it..

If you want to use my car as an example, switching over from a stainless steel 19" Flexalite 6 blade fan to an electric fan improved my max highway mpg from around 22 to just over 24 . That flex fan moved a lot of air, but consumed a lot of power as well. The car was a little faster too.

1980 Aspen
1bbl 225


Mitch

A belt-driven fan consumes hp that varies with cube of speed. That is, if you double engine RPM, the power consumed by the fan increases 8 times. An electric fan would reduce parasitic hp but earlier dyno tests showed that a belt driven fan only used 2.67 hp (in one test) at maximum hp, which would be significantly less at highway speeds.

An electric fan would be used mainly at idle, which is where Chrysler alternators typically have weak power output. It would be a good idea to upgrade to a Denso alternator if you want to convert to an electric fan. A more cost-effective alternative would be to switch to a clutch-fan if you have enough room between the water pump pulley and the rad. Narrow a-bodies (1966 & earlier) are very tight but SSDan has found some clutch fans that fit the newer (1967 & newer) a-bodies and likely trucks too.

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1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech

I am a fan of running electric fans verses the stock fan. There are many benefits that help provide better mileage.

1. Drag is one but,
2. the biggest benefit in my book is engine temp. Faster warms ups in the morning are great and the choke kicking off sooner because the fan isn't blowing air over the manifold.
The number one cylinder actually runs much cleaner, even with the rest.
You may think this is a subtle change but for short drives, it makes a big difference in mileage.
3. Another big benefit is during heat soak. On super hot days instead of boiling all the fuel out of the carb.......I leave the fans armed so it cools the intake and carb down so when you jump back in the starts are instant........no putting your foot to the floor and cranking till it catches.

These are little things but over time they really add up. The Denso alternator is a nice addition especially since you can get them so easily. However, I never had a problem running the fans on a stock alternator.

It is like installing a mini-starter next time instead of installing another boat anchor stock starter. At our auto parts they are the same price....$40.00.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks for all the replies . I will definitley be doing my research on it , and what to pick up , and how it install everything for when I finally decide to do it.
Thanks again
Dave

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81 Dodge D150
It looked easier in the book .

wanna boost power? Use an electric water pump. That water pump is an engine dyno in itself! Maybe a Moroso type that uses a cog and a small electric motor or you can go balls out and get a davies-craig external electric pump with a duty switch on it that cycles to keep a specific water temp (remove the thermostat) but youll have to monkey with the way its installed.

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I didn' t buy it, I built it.....

I think the energy needed to operate the water pump is the much the same regardless if powered by electrons, or mechanically via crank shaft if it is continually running. All that is happening is mechanical energy is converted into electrical energy by the alternator, where there may be some losses realized during conversion.

Where energy savings can be realized is if the water pump can be cycled on and off while engine is running, something I would not want to try, unlike the cooling fan that can have a intermittent duty cycle, and still safely cool engine.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I don't know that I would be willing to switch to an electric water pump for road use.
Any electrical switch, fuse, connector, wire, or just a thrown belt, and the pump is shut down. I've seen several failures out at the track. where things can be caught fairly quickly. Out on the road, just a few moments of inattention, the engine can dangerously overheat, and you could be thumbing it.

It's common practice to leave the water pump off during initial warm up at the track. I've seen that bite people, when they forget to turn the pump back on.

2¢

CJ

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Part of Tyrde-Browne Racing

Electric on demand water pump typically only pumps what is needed to cool motor. A water pump running over what it needs to cool the motor is wasted energy. If you can cycle on/off with a simple thermo switch (I believe davies-craig regulates the voltage) it works in an averaged low amp draw state. Meziere and Moroso units only draw 8-12A (.25-.4HP) under load, while electric fans draw 15-30 and can spike to 100 when kicked on. Typical V8 water pump is 7 gpm at idle and 70gpm at 6500, @7-20HP to run them. You dont need 70 gpm to cool a motor while 7 may not be enough. Is 70 GPM through a radiator time enough to cool it?
Figure a 12V electric pump motor pulling 12A and then convert to HP (....In a 13.8-volt charging system, our alternators draw one horsepower for every 33 amperes of load current..........) I bet dollars to donuts its less than 1hp, is it .165hp?". 1/2 HP is less than the 7-20HP realized on a mechanical water pump. Just food for thought. Meziere is about 42 gpm full boogie and has a brush life of ~2300 hours. I got one on my stroker small block. OK who's gonna step up and make one for a slant? MEziere/Pro Comp Mopar B/RB and LT1 is just a motor and an impeller, would make ideal candidate for a slant water pump. Graft motor onto Slant shaft and bingo, electric water pump.

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I didn' t buy it, I built it.....

First of all I would like to see how much pressure it take to blast 70 gallons of coolant through a passenger car radiator, I suspect it is magnitudes higher than the head pressure capabilities of an automotive water pump.

70 gallons a minute would perhaps be true if one were pumping from one barrel to another with no restriction or head, but the close loop cooling system is throttled by thermostat, radiator flow characteristics, small internal passages with flow slowing twists and turns limiting volume actual moved by a low head pump. There are times little or no flow takes place in a cooling system when thermostat and heater core loop are closed. At low or no flow condition coolant is just twirled around in pump body not entering or leaving, not much energy is needed for that condition. Work = mass x distance.

Where auto manufactures haven’t incorporated electric water pumps across the board (Prius now uses an electric pump) as they have with cooling fans, and to some extent power steering, I suspect it is not a practically ripe area of accessory rooted wasted energy in the industry’s quest to ring out as many mpg’s possible in these days of expanded CAFE regulations. That being said, manufactures apply cost benefit analyses to all areas of design; coolant pumps must not make the cut at this time, and there are other areas that can yield more savings for less cost such as aerodynamics.

It looks like a 2011 Prius uses an electric water pump, a change from earlier model years. So it took ten years to rid this model of mechanical driven pump.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Sure, the GPM on a water pump is a relative measurement. What does it take to turn an impeller against a static water @ 100-1000-7000 RPM? It's not going anywhere when the stat is closed (sans minute heater core and bypass) Is it creating its own air space (destructive cavitation?) wouldnt it be nice to just turn it off when its not needed? That is my thought. Hydrodynamic engineers, step up! Wonder if they ever investigated viscous or electromagnetic clutching the water pump like a fan or A/C compressor (heck, Mad Max did it in the movie on his supercharger! ) . It WAS all in the name of reliability and warranty work, but that is pretty much thrown out the window on a 50 year old classic car.

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I didn' t buy it, I built it.....

Do not use a Moroso style water pump drive on a street car. That motor is just a heater blowermotor, and was not designed for the loads inposed by a belt drive. The motor draws way more current then it was designed for and runs hot (it will burn up in street use). Also the shaft bushing will not live with the "side loading" imposed by the belt drive (it will fail). Ask me how I know this.

The davies-craig unit looks nice, but is it the cost/benifit worth it?

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

just found this, sums it up pretty good, but we never see 9600 RPM at the pump like htese guys do. So I guess at 7000 it MAY be creating its own steam pocket to spin in unobstructed..but this may be overstepping the bounds of our low RPM discussion...

Race car engineer: "....the problem with water pumps is something that I see every day with the motors that I work on. These things rev to 8500 RPM and many times the pulley on the water pump is 20% smaller that the one on the crankshaft. So at 8000 Engine RPM the poor pump is turning 9600.

When you turn a centrifugal pump that fast you can in fact lower the "pressure" at the inlet to the pump to ZERO. Yes, you can run an 18 lb. cap, and a thermostat, but if the pump is turning so fast that it creates a low pressure zone at the inlet to the pump, then water will instantly boil and turn to steam. With coolant it will be less severe, but it can still happen.

Now centrifugal pump do not move steam at all well. In fact they do not move it at all. So all water movement in the system ceases. This starts a chain reaction. The area where there is stead will not conduct heat. The causes the area adjacent to the steam pocket to overheat, etc etc etc. ..."

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I didn' t buy it, I built it.....