Ken, the reason the 14's run at a lowwer RMP pulling 50 CFM less is amp draw. It takes more amps to pull the same CFM because of the larger load to the motor from the larger fan blades on the 14 that are metal as where the blade on the 12 is composite, and also the area the 14 pulls in is larger.

This is what I'm pondering, more area @ 50CFM less per fanor less area @ 50 CFM more per fan.

The amp draw you must admit is awsome only 7.5amps for 3000CFM for the 12"er and only 9.5 amps for 2950 CFM on the 14"er. The motors are pancake stylestainless roller bearrings (kick butt constuction).

BTW the mark fan I read on a ford site draws about 30 amps nominal, a lot more than the ones I found, 2 12's draw a mere 15 amps to pull 6000 CFM and2 14's 19 amps at 5900 CFM.

Forget that $590 setup making shroud/ coolant/ wiperfluid resivour issues, buy the two fans around 200 bucks, the control circuit parts $100-$250 more depending on how ya wire 'em, go junkyard hunting for shroud/ mounting parts or get a 4'X7' sheet of 20-22 gaugestainless or aluminum, some matching 1/8"thickX 1" wide flat stock and stainless nuts,bolts, and washers and fab the install to retain the stock upper shroud. Sheet metal sheers, handtools, and a drillwill do the job, but use of a sheet metal brake and plasma cutter will make it easier and quicker.

Damn I should fab one up, patten it and sell it for $250 a pop.

 

I thought about that if I can get them to work!

 

Welp, after doing alot of research, I am almost convinced that this MarkVIII fan will not be enough to cool a 5.9 Durango running with A/C in areas that can approach 100 degrees outside. Also, if you do moderate towing, and/or combine it with the a/c and outside temps, it'll run hot. A couple users that tried this already stated the obvious results with a single or dual fan setup. Bothfan setups may not had enough CFM's to keep the big engine cool. I will have to agree with Lil Mopar and go with a minimum of 6000 CFM's to keep the 5.9 cool whether it be a big single fan or dual fans.The Mark fan may work for a 4.7 or 5.2 and even then, as long as you don't really tow anything and living in very hot climates like Texas, it should be enough.

 

Cess it's too bad you don't live near me, I got a fridge in the garage filled with 2 cases of New Castle, a case of Heinekin, and the door is loadded with Bud Light,Miller, Coors and what ever else the tourists tip my mother-in-law. My habit is suck down a case all at once and not have another drop for 6 months.

Anyways I'd invite ya over with e-fans in hand and at the end you'd be up and runn'n no switches to have to remember about, and I'd make shure you understood how it all works, cause once ya get it it's easy nothin' to it but ta do it.

Not in an effort to confuse you, but when I was in electrical class the instructor always said to think of it as one wire, one path from start to finish. If you break down a circiut, you must have 5 things to make a complete circuit, A supply of power, conductor (wire) to move the power, a switch, a load (motor,light or other power consuming device), and a complete path to ground for the electricity to flow through, anything else is not a complete circuit and will not work.

Try looking at Ken's diagram and follow the circuit from to power supply through the switches, loads and finally to ground, and break it down, compound circuits can be broken down this way also, follow the low speed fan circuit from supply to ground, then the high speed circuit, follow it with your finger like a road map. Get the parts out and lay them out in sequence on the floor/table or what ever.Once you have them sitting there, identify all the + (power in for dc) and - ( power out dc) terminals and determine how they need to be hooked up from 1 linefrom power to first part in line up all the way to the end of the circuit being the wire to ground.

Relays, don't let them bother you they are our freind as they are the "little man under the hood" swicthing loads on and off for usautomaticly in a control circuit.

A relay is nothing more than a switch that is contolled by a coil. A basic on/off relay has 4 leads, 2 for power in and out on the swicthing side and 2 for the coil, it will be marked NO (normally open, open meaning without power to the coil it is in the off position or off when at rest) NC (normally closed or on at rest with no power to coil).

The coil when energized creates a magnetic field that moves an iron rod that is connected to contactors in the relay, in the NO relay this rod would be pulled into the coil, when energized,making the contactors connect and pass power to the load and in the NC relay the rod would be pulled into energized coil breaking the connection to the contactors by pulling them apart and cutting power to the load shutting the load off.

Damn I do wish you lived near by I'd have yacomeover, we could wire it up real quick, suck down a few beers and compare notes on our D's.

Man good luck Cess, I feel like my hands are tied, we could get 'er done in at worst an hour or two counting unforeseen cans of worms.Well I hope at least I helped in trying to give you a different perspective in which to look at the wiring end of it from.

 

Ken, even with the 6000CFM setup, I think a trans cooler should also be installed seperate as in not running tranny oil through the radiator.

With the amp savings over the mark fan @ about 30 amps, the ones I scoped out pull 15amps twin 12"ers runnig at the same time and 19 amps twin 14"ers running together, this will leave some amps handy to run a 10" Perma -Cool pn 19010 @ 2100 RPM @ 1250 CFM @ 5.7 amp draw through a 11"X11"X1.5" B&M supercooler on t-stat control and this cooler also has a flow check that lets cool oil bypass the core and return to the trans as added insurance not to starve the tourque converter of oil.

The fit aint perfect as the cooler's core is only 11"X9" and the fan covers 13"X10.5"X2.5"thick, but the cooler's overall area is 11"X11" and the fan's blade is 10" in diameter so it should'nt be hard to center up the fanblade over the cooler and persuede maximum airflow through the core.

I know why not a smaller fan , well the other ones draw more amps and give less CFM, so I'm stuck on these efficiant fans for that reason. I can run three of them at an amp cost of a hair under 30amps, get the trans off the radiator and cool it's oil more efficiantly adding life expectancey to it, ditch the clutch fan adding hp&mpg and still have enough amps left to ditch the water pump for an in-line 55gpm electric unit adding yet more ponnies and mpg. I'm gonna give my 360 a present it has been missing since the late 1960's, I'm gonna give it back it's *****.

 

Ken, can you point me in the direction of where you read about the fan not being enough. I'd like to read there responses.

I guess at this point it would be futile to try with the mark fan again. I guess My best bet at this point is the dual 12's?

Lil red, what exactly are you talking about with the tranny cooler?

 

Cess,

The statement I made is my own opinion based on the research I did searching the net looking for a Efan for a Durango or even a Dodge RAM. Only Flexalites makes Efans designed for Dodge RAMS but they do not have a listing for Dakota/Durangos. But since the RAM shares the same engine(base on 5.9),maybe the RAM's may have bigger radiators, Flexalite makes DUAL efans designed for RAMS, especially for the 5.9 cummins. If they claim that 5500-6000 CFM's is enough to keep a hard working cummins cool, it should be enough for a gasoline 5.9 engine as well. With minimum CFM ratings of 5500-6000 CFM's. So I am making my judgement call that this should also apply for Dakotas and Durangos with 5.9 engines as well but may have to find a smaller dual Efan that pulls the same amount of CFM's that will fit on Dak's/Dur's the smaller radiator. Hence where Lil Mopar recommends the dual 12's that can pull 6000 CFM's with relatively low amperage draw.

With this setup, you're garuanteed the D will stay cool no matter what part of the U.S. you live in and using the A/C and towing.

Otherwise, I can see the Mark fan work for those D owners that;

Lives in the northern U.S. regions where the daily summer temps aren't as hot.90+
Do very light or no towing.
Not use A/C much.
D's with 4.7/5.2 engines.

 

Cess the tranny cooler thing I was yapp'n bout goes like this.

B&M makes a tranny cooler that's total dimensions (counting the "side tubs") of 11"X11"X1.5"thick.

This is the only cooler in my opinion worth slapp'n and e-fan on because it's the only one big enough to but a 10"er on. Also it has a flowcheck valve that let's already cool trany oil bypass the cooler and return to the trans, this is insurance that the trans oil will never get too cold and thicken up taking up less space and starving the torque converter F'n up the trans.

Reason for adding the trans cooler: to remove the tranny lines from the radiator relieving the radiator of the added heat load of the trans oil. I in a stock D that does'nt have tow pkg upgrades there's no tranny cooler the radiator is responsible for removing heat from both the trans and the engine.By having the trans cooled by means of a seperate cooler, if done right, should benifit the powertrain by having a trans that runs a little cooler the trans should last longer, by having the radiator only cool the engine it should do a better job without all the extra heat load of the tranny oil circulating through it.

The fan circuit for the tranny cooler would be controlled with the same type of temp probe setup used for the radiator fans. I'm buy'n 3 of 'em, one for the trans cooler and the other two for the twin radiator fans. An adjustable temp fan control set to come on at 180 and turn off at 160, I found when looking for a trans temp gauge, that the trans oil must be kept in the same temp range as the numbers on a coolant temp gauge start at about 120 and go to about 260 and the trans temp gauge numbers are the same so I figure same temps means I can use same fan control units.

The fitting issue: the B&M cooler's core area is 11"X9" and the 10 fan needs 10.5"X13" to mount. The fanblade itself is 10" diameter, so if I mount it right, the fanblade will go 0.5" past the right and left side of the core but will not see open air because this 0.5" over lap on each side will be blocked by the side-tubs of the unit. With this said, fabricating the nessisarry mounting system for this e-fan cooled trans cooler will require seriuos thought, preperation and maybe even some trade skills such as welding and sheet metal fabrication skills.

Why a 10" fan and specifically why the one I recommended by part # and make: The 10" fan I mentioned a post ago can pull 1250 CFM air flow and only draws 5.7 amps, no other 10" fan I've seen even pulls 1250 CFM and the smaller ones like a 6" pull as little as 350 CFM and suck as much as 25 amps from the electrical system, so this is why my fan and trans cooler shopping list look this way.

My build will have 2 12"ers on radiator pulling 6000CFM @ 15amps and the trans cooler a 10"er pulling 1250 CFM @ 5.7 amps. System net CFM = 7250 System net amp draw 20.7 amps. I'm pretty sure that my stock e-fan pulls 30amps and it sucks compared to what I'm about to do, because if I'm right the new set up will draw less amps than the stock secondary fan so I won't have to upgrade my alternator and I should have enough capacity to run an inline electric water pump that pumps 55GPM so I can ditch the stock water pump and add more hp and cooling capacity, the stock water pump only pumps in the neighborhood of 20GPM.

It may sound overkill but tranny's and engines aint cheap and overkill is this engineer's middle name , when I fix something I intend on making it last a while.

 

I have the tow package on my 99. So I do have a seperate Tranny cooler, right? on front of the radiator?

 

Very good info!!

Ihave not yet done the E Fan conversion for the reasons mentioned above. It gets 100+ here often and pulling a 22' camp trailer in that heat would just overpower a E Fan set up such as the Mark 5 set up.
Reading lil red mopars posts confirms that in my mind. I am a HVAC/ tin bangerguy, I dont think bending up a shroud out of metal would be to tough. It could be made as thin as possible to keep it close to the rad then we could cut the holes for the fans where we wanted and mount the fans over those holes....
I'll look into this in the future but I'll guess even a sheet metal shop could make something if givin the specs for less than $100.00. we would prob need to figure out the mounting tabs (they could be bent to be in the correct place but they may charge more for this).