Electric fans on a 24v?

[LSMITH]

Has anyone looked into using electric fans for cooling rather than the engine driven fan? Hot rod gassers have done this for years. I have been told that the engine driven fan uses 20 horsepower at 2800 rpm, and getting that power back would be nice. Does anyone know for sure how much power the factory fan uses? TIA.

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99 2500 QC 4X4 AUTO SB 24V LARAMIE SLT 3. 5 LSD 285-75-16'S Everything but leather NRA Member

 

[HEMI®Dart]

LSMITH,

I looked into this. It doesn't look like electric fans would be able to pull enough air to cool our trucks. In the winter, sure. But in the summer, towing and hauling, very doubtful. #ad


In my findings, I'm sure the stock fan uses at least 20hp. I have been running fanless this winter. Truck definately has improved throttle response.

About the largest fan setup is Flex-a-lite's model # 260 Universal Dual 14" Puller fan. Its rated at 5300cfm.
Its not cheap, and probably would need some massaging to work on our application, and probably wouldn't meet the cooling needs of our engine. #ad


#ad


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Bill R
94 2500 SLT 4x4 5 Speed, 3. 54 LS, JRE 4" exhaust, Autometer Pyro, Boost & Water temp gauges, Bosch 215 HP injectors, Timing @ 14. 7º, JRE Stage III #4 plate 270/675, AFC spring kit, Scotty Air, Bully Dog Propane Injection, Roadmaster Active Suspension, Optima Red Tops, Geno's Exhaust Blanket, Espar Heater (won it!), Synthetic lubes throughout.



[This message has been edited by HEMI®Dart (edited 02-01-2001). ]

 

[Deezal Man]

Its my opinion that an electric fan would do just fine for the guy who doesn't tow at all, or tows very lite loads. Especially if hills are not involved. When your truck'n down the road at average speeds... the fan does nothing but create drag. Where the fan is needed is when your pulling a hard hill doing 20-30 mph. . Or sitting in traffic. But again, I think the electric could handle this situation.

I looked into that dual electric fan set-up. Frankly I think it be worth the little extra cash to buy the Horton.

Neither are inexpensive improvements and will take a lot of time to repay thier investment.

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98. 5' 24v 2500 Auto/3. 54 4x4 SB QC 285-75-16's on Alcoa's. Everything but leather. PIAA 1200's, AMSOIL dual filter relocation system, Smittybuilt Stainless Steel Nerfs, Rhino Liner(Junk), K&N air filter(For Sale)15 year AMSOIL dealer. Time permitting, Soon to include Ultra-lite Pyro,0-50lbs boost, Trans temp in the pillar. Rancho 9000's with in cab adjustment.

 

[Vaughn MacKenzie]

Hemi-Dart, what we need to find out is what CFM the stock fan flows during full engagement. I have a hard time believing that a twin fan setup cannot outflow the stock fan. Take a look at the stock fan. . . it is not that huge.

I remember seeing a post by someone a long time ago commenting that their Horton never engaged while cruising the highway in the summer, towing a decent load, even on a grade. The only time it did engage was when driving in heavy stop & go traffic in town on a hot summer day with the AC on. Maybe some Horton owners can jump in here and tell us if this is true or not.

Vaughn

 

[highland]

I'm still waiting for just ONE person to reveal an electric that has been installed and proven to work while towing under load. Just ONE! (I do not think it will happen - Go with a Horton - they work - and you can feel the extra power when they are not engaged).

99 QC, Horton, MagHytek

 

[Pete Peterson]

Just go to your local electric motor shop and tell them to let you see a 25hp motor and thats what you will need!! Pete

 

[David_VT]

You know, I went down this path a long time back. Seems the fan topic is not as 'sexy' as clutch research or other rubber to the road type of parts.

I hope that somewhere out there is a closet fan expert who is brave enough to share the real truth on this.

Come on, how about a real down and dirty CFM/HP/thermodynamics/ indepth tell all about the fans.

Seem to me (for example) that if I can leave my stock fan in place and it will suck me up a hill with the transmission in neutral, then we should be able to find an electric fan that can do the same thing (or not).

#ad
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Heck, I found a page on the web where some guy had mounted a stack of PC fans on his intercooler and had all kinds of measurements to show how well it worked in stop and go traffic. (little turbo gaser, not the cummins)

Another page had a guy running a turbine off of burning wood so that one could power an electric generator...

Come on out you fan fellas! We know you are there somewhere... #ad

 

[drawson]

I will be running two electrics this summer. I am no expert on these electrics fan but here are some of my thoughts... .

The belt driven fan can restrict the air flow above 40 MPH. This is even more a problem on our slow reving Diesels. On Gasser pulling a hill the shift down and rev high(3500-4000) to keep cool.
Above 35 MPH there is no need for a fan, the air flow created from the vehicle moving through it is more than enough for everything with the exception of the A/C.
The only way I think an electric might not be cut the mustard is if all you do is pull a really heavy load under 30 MPH all the time.

I already have a 15" on the right outside of the A/C condencer that comes on with the A/C as well as a manual over ride switch inside the cab. I use it right now to cool the EGTs before shut down. It is really working well and has cut my idle shut down time in 1/2.

I have also towed a back hoe a couple of times with just this outside fan and my lund winter front on. The engine nor the EGT have not been a problem at all although the temp has never been hotter than 45 deg.

I have an 18" fan for the inside that will go in sometime this spring that will be hooked up to an adjustable temp sensor as well as a manual over ride.

Maybe the rams with Auto trans might not be able to get away with electric fans, but I believe that the manual trans will not have a problem.

I will have this set up this summer and will keepyou all informed on how it is working.

[This message has been edited by drawson (edited 02-02-2001). ]

 

[HEMI®Dart]

Vaughn,

I don't know where to find the CFM for the OEM fan. I'm not sure why its so secret. My fan measures 22" and 7 blades. A decent sized fan.

I took my fan off for the winter. It ranks as one of Best things I have done. Warmup times are cut in half. Throttle response is definetly improved. Fuel mileage jumped back up to summer months average. Truck is much quietier and seems to have more torque at 190 degrees.

When the guy said his Horton didn't come on at all during the winter, I believe him. My truck runs at the same temperature without the fan as it did with the fan (winter months). The trick is to block the Radiator to bulid heat into the system.

A 24 Valve truck may be different. I'm not sure.

I Don't want to put the stock fan & clutch back on this summer. I wish Horton was a liitle more affordable. Cyclone fan was supposed to be developing an electromagnetic cluch like Horton's. But about 1/3 less $$.

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Bill R
94 2500 SLT 4x4 5 Speed, 3. 54 LS, JRE 4" exhaust, Autometer Pyro, Boost & Water temp gauges, Bosch 215 HP injectors, Timing @ 14. 7º, JRE Stage III #4 plate 270/675, AFC spring kit, Scotty Air, Bully Dog Propane Injection, Roadmaster Active Suspension, Optima Red Tops, Geno's Exhaust Blanket, Espar Heater (won it!), Synthetic lubes throughout.



[This message has been edited by HEMI®Dart (edited 02-02-2001). ]

 

[Rambling]

Hemi,

I noticed on the Flex-a-lite site for those dual 14" electric fan you posted they should work for light-mild duty service of class 5 - 8 trucks. They just might work for the big C. Maybe not a super Bombed one, but up to a moderately Bombed set of wheels.

With a manual, positioning for air flow shouldn't be as critical as it would be for an Auto.

The site didn't say if they were switched on independantly. That would be plus, don't you think?

 

[hadi]

The problem is getting a fan that can really output what it claims. Many after market fans 16 inch claim they can pull arround 2800CFM/per and they usually draw around 10 amps in power. I was confronted with that situation when I dropped the modified 24 valver in my Hummer which has bad air circulation to begin with. I bought a Flex-a-lite 16 incher claiming 3000 CFM from OEM specs. At that point in time I was considering doing an aluminum radiator for optimum performance so I got talking to BILL KIDD in Canada. Bill knows aluminum radiators. He advised me to get the proper cooling fan set up before graduating to an aluminum radiator. When I told him about the the fan I wanted to use he advised me against it. He went on to name a few other brands comonly found in performance parts catalogues IE; black magic , flexalite and a few other and said he had tested them agaist this fan he sell that is made in Italy. I cannot remember the name but I will look at it in the morning and post it or you can look Bill Kidd in Ontario Canada up. Needless to say this fan draws 20 amps in power,twice what all the other fans do and has these unique looking blades that are individually balanced. With this set up I have never had a problem even while testing the vehicle up at Fort Worth millitary testing grounds in mid summer outside temp around 110. Please keep in mind that I do not tow but I do drive the vehicle hard, real hard especially through the testing phases.

Hope I could help

Hadi

 

[David_VT]

I doubt any money will be saved here, but check out these electric fans... I think I saw one that draws 100AMPS... wow!!
http://www.electricfanengineering.com/index.htm

Here is another that came from an application sheet which listed our Dodge Cummins. The model was '260' which claims to put out 5200CFM at 30AMPS... http://www.flex-a-lite.com/auto/fulltruck.htm

What is interesting is that Flex-a-lite is encouraging the users of Towing and RV's to keep the mechanical fans as primary but add their electric fans for aux. cooling... hmmm

[This message has been edited by David_VT (edited 02-03-2001). ]

 

[Vaughn MacKenzie]

Here is something else to ponder. . . it is airflow through the radiator that dissipates engine heat. As long as there is air flow, heat is being dissipated through the metal fins of the radiator. The faster the air is flowing, the more rapidly it dissipates heat. . . up to a point. At some point the airflow carries heat away faster than the radiator fins can transfer heat from the coolant to the outside air. You could greatly increase air flow, but not increase the rate of cooling.

I have no idea at what rate of airflow you reach that "point of diminishing returns" but of course it varies by temperature, humidity, etc. I would guess at highway speeds you have already reached the limit of heat transfer rate.

IMO the purpose of a fan is to generate air flow when there is insuffecient air flow for engine cooling. Of course slow-going in heavy traffic on a hot day is one of these instances, a time you really need good air movement. Don't you think a pair of decent electric fans generating 5000 CFM could easily outflow the stock fan at idle, fully engaged?

What about towing a load up a steep grade on a 100F day?

If you take a look at your stock radiator and fan setup, how much of the radiator is the fan acutally pulling air through? Maybe 60% at best? The fan is shrouded, that's good, but with only 1" of space between the shroud and the back of the radiator, that doesn't leave a lot of room for air to pass through the radiator then escape quickly. When air does pass through the fan opening it crashes into the front of the engine.

Image a couple of decent electric fans side by side, channeling air over more of the radiator and directing it to the sides of the engine where it can flow through more easily. I think underhood ventilation would be improved, carrying exhaust and intercooler heat away as a side effect.

I'm not trying to be an expert on the subject, but wanted to toss out some ideas to ponder. In the past I've been sure something I tought up would work, only to discover I overlooked something and was totally off track!

Vaughn

 

[David_VT]

Vaughn,
Once I started pricing some of these big electric fans, I quickly realize that we are running up into the Horton's price range real fast. It is kind of ironic.

I wonder if someone could replace the OEM hub with something like an electric AC pulley, thus giving us the on/off control??

 

[HEMI®Dart]

Cyclone was supposed to be developing an electromagnetic clutch for the B series engine. I don't know what happened.

Good Fan Tech : http://www.usgear.com/cyclone.htm

 

[Mac]

This is not exactly the application being discussed, but it is similar. Awile back I was the owner of a 95 Dodge 360 gasser, towing a 22 ft fifthwheel across the upper US to Washington state. On a hot day up any hill I would tend to overheat. Never boiled over, but way up near the red. My fan would hardly ever kick in, but when it did it would bring it down.
In Oregon I bought a 16 inch electric and mounted it in front of the radiator with coathanger wire. I turned it on and left it on the remainder of the trip back to Georgia via Laughlin, NV. and it was hot down there. With the electric fan the Temperature didn't get as hot and the clutch fan never kicked in. I found out when I got back that my fan clutch was bad. It may work on the Cummins.

 

[Racechaser]

I remember our buddy Sam Memolo installing an electric fan on his dually in an episode last year. You may be able to look it up on shadetreemechanic.com if the page is still up. #ad


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'01 2500,4WD,Ext cab,sb,auto,3:55's,sport pkg(horrible cartoon decals removed),flame red,tan lthr,clearance lamps,everything but kitchen sink. 1st Diesel,never buying another gasser!

 

[Cooker]

What fan did Sam put on his truck?

 

[Chad Sheets]

The variable speed clutch fan is popular for several reasons. Primarily it saves fuel consumption. It reduces noise, and gives an increase in usable HP.
All these things together make the fan drive very appealing to some people. It doesn't matter if its electrical, viscous, or pneumatic (Horton makes a Diesltemp fan clutch that engages by air psi and disengages by spring tension, and runs off a solenoid) the fact remains that the fan only runs when the engine warrants the operation. I am sure there are other fans out there for our ISB's that are in the variable speed family that cost less than the Horton model everyone is talking about.

Its kind of like the Banks argument. Yes it works and works well with my engine, BUT, is it worth all that extra money for me to gain so little? If I owned a fleet of trucks that were on the road 10-12 hours a day, then yes, they would all have a Horton fan clutch on them. After all, my goal is to save as much money in operating cost as possible for the company. If its for my own personal truck, I doubt I would ever see the cost savings to pay for the product in a 5 year timeframe, and the minimal loss of 20 hp is not an issue.

If power is what you are looking to find, the engine looses aprox 25% of its rated HP through out the entire driveline from transmission to tires. That would be a good place to look, and might be a little cheaper as well if you find the right cure.


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Always ready to help!
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