Electric Engine Cooling For The 6.9l/7.3l Navistar Diesel.

Our Original Article was damaged in the Webshots implosion and we lost all the pictures for converting to an electric fan. Hopefully these thread will help anyone seeking to do an electric fan conversion. - Moderation


first,understanding the IDI's normal operating temperatures.

Quote:
Originally Posted by Dave Sponaugle View Post
If I had an electric fan that was reliable I would leave that fuel sucking stock fan in my garage.

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the ideal temp for max performance and fuel economy is much higher than some people think.the diesel engine is not like a gas engine that prefers lower heat.
many people think,the cooler the better.this is not so,with any fluid in any component of your truck.every part of the drivetrain,yes including auto transmissions have a preferred operating temp (which is 150f minimum,and 175f ideally by the way measured in the base/pan of the trans.)

Quote:
Originally Posted by PLC7.3 View Post
Originally the IDI diesel came with a 4 row HD brass rad....... I don't understand why they are selling aluminums as replacement.....
Diesel engine coolant temperature at the top of the radiator where hose attaches after high rpm or under load condition for 20 minutes should be (195-237*F) 91-114*C nice time to have a temperature reading point and shoot tool.
CAUTION:
The specified/required thermostat does not contain an internal bypass, since the bypass is located in the cylinder block. Whenever the thermostat is replaced, it is mandatory that only Motorcraft E5TZ-8575-C or Navistar 1807974C94 thermostat be installed.

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Quote:
Originally Posted by PLC7.3 View Post
Do you know which Tstat is installed, do not use aftermarket.......could be the clutch fan is locked up and not unlocking. Do the fan test at the address I sent you.....email.

CAUTION:
The specified/required thermostat does not contain an internal bypass, since the bypass is located in the cylinder block. Whenever the thermostat is replaced, it is mandatory that only Motorcraft E5TZ-8575-C or Navistar 1807974C94 thermostat be installed.
CAUTION:
Do not attempt to repair any thermostat. It should be replaced if it is not operating properly.
Check the new thermostat before installing it for correct opening temperature. Before suspending in boiling water, with a flashlight check where the rubber and the flat metal flange meet for bad seal. Tstat should start to opening barely at 180-192f, fully open 200-212f, allow to cool and check for rubber seal again.
Removal: Disconnect batteries, drain 4+ gals A/F, remove: as required, fan belt, alternator set aside, alt bracket, remove filter support from fuel filter then e/block. Disconnect upper rad hose at rad, remove tstat bolts and housing. Clean both faces, depression and holes in block, ensure check ball in goosekneck is clean, free and rattles "do not remove".
Installation is reverse proceedure, I do not use sealant on gaskets and faces. REMEMBER the tstat pellet(copper end) goes into the block. I do use a "very small amount" of sealant on the edge of the tstat face when installing into the recess, now go for coffee, allow sealant to setup, this has saved me from tstat slippage when the gasket and goosekneck are installed. Replace all items in reverse order......
Manifold bolt torque......... 20ftlbs

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what then are safe normal operating temps for an idi engine according to a real gauge? if your not new to diesels,this won't surprise you any.if you are,it probably will:

Quote:
Originally Posted by Dave Sponaugle View Post
If I stand on the throttle up some of the local hills on the interstate at 70 MPH, 235 to 240 is what I see for temps with my gauge in the same location as yours.

When you think about it 220 is only 25 degrees more that what it takes to open the thermostat or minimum operating temp.

237 at the top radiator hose is within spec for a normal temp.

From everyday driving.

It takes a good grade on a warm day for me to hit 235, but it has been there many times.

The test proceedure for the fan clutch also gives 237 as the upper radiator tank normal high end temp.

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secondly,why consider swapping to electric cooling fans?



1.safety/ease of working around running engine (examples; timing engine,diagnosing sounds,priming fuel.)

2.free up hp.who wants to feel a power loss and slow down even more while towing uphill because your engine fan kicks on? let's face it,everyone wants the majority of their power to remain at the back wheels at all times.especially when you need it the most.
the idi isn't a powerful diesel engine as far as hp goes by modern standards.they can be built to impressive levels.however this requires thousands of dollars,engine removal,tear down and or possibly complete overhaul (depending on what your after.)
as worthwhile as this may be,not everyone has the funds,time nor desire to completely remove and start tearing into their engines.there are small gains to be had in other places.this is one of them.
some idi owners with years of driving these rigs under their belt,have estimated 20+ hp loss when the mechanical fans engages.this may not sound like much,but it's a pretty good chunk when only talking about a 180-190 hp engine (at the wheels) with a typical aftermarket turbo kit.just 120-130 hp with an n/a engine.
we also have a dyno report:

Quote:
Originally Posted by MGehmanF250 View Post
Hey this is Marnin, known as dieselgiant at Oilburners. I've dione the Windstar E fan conversion this past spring and it has done exceptionally well over the summer. And in regaurds to Hp gains I've dynoed since the 137hp to 149.77hp. After the E fan convertion and a few other small modes it made 175.3 Hp on Beans diesel dyno. The engine also revs up faster. My 7.3 is still NA.

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3.efficiency/economy.electric fans are much more efficient.generate some their own power while running and require no power at all when off (which is most of the time) unlike a fan just spinning in free mode.it all adds up.

4.stock fan clutches are expensive and failure prone.replacements these days seem to be even worse.high end clutches built to last and work much more efficiently can set you back for more than a typically good used idi engine,making them an impractical option for most idi owners.

5.a fairly common event over the years,has been reports of idi engines tossing their fans through radiators.these are not cheap.while some may claim its due to improper installs etc.it's also happened at various random times upon engine shut down,not just after fan clutch replacements.

6.far better cooling at idle.this means colder a/c in the summer.cooler engine while plowing snow and other slow driving, or idle off road work and play duties.

7.quieter engine.it's well known the stock fan really roars when engaged.i hear nothing,and in fact had to install indicator lights to know when they're working.

8.reduced stress on water pump bearing.

9.off roading driving in deep water.you can turn the fans off (best research how the motors seem to hold up after being submerged in water though lol.)

10.faster warmup.though we have a t-stat,so it's not a major issue.when starting your engine with a mechanical,it blows cold air over the engine and trans.this means not as good for emissions either (though this is not a commonly known concern in this section of the forum lol) and economy gains there too,though unmeasurable in this regard im sure,but hey,it's there.adds up over ownership.

11.fully adjustable air flow at a temp you prefer with a variable rate/adjustable controller.you can tune it for your driving style.or full on pre-hill to keep her from even getting hot for that monster grade coming up.

12.reduce head gasket failure.e-fans used in conjunction with a variable rate fan controller that slowly ramps up the airflow,will slowly bring the temps down and keep them manageable in the first place.when the mechanical engages,it can often be latter than you would like,and then it's just full boar all at once.this drastic quick change in engine temps can warp heads and isn't any good on head gaskets.

13.ease of replacement.
should one of the electric motors fail,replacement is extremely easy,and might take 5 minutes total.

14.cost of replacement.
should one of the electric motors fail,replacement electric motors,even new cost around $40 (ford 95-98 windstar example.at time of this post and price check on ebay.)

15.quick extra cooling for auto trans aux cooler.with an override switch,you can turn the fans on to help pass air through your aux trans cooler.when driving below torque convert lockup speeds,this can be very helpful.iv done this when plowing snow even if the engine temps are fine,the trans temps can creep up quick.

why not consider swapping to electric cooling fans?

it requires time,money and a little effort to do it correctly.if you lack any of these,it's best to skip this mod,otherwise you will fail.

third,what is required to convert from a stock,energy robbing,failure prone,mechanical cooling fan for electric?

here is the list.
CAUTION!
if not followed,you will fail and complete engine failure could be the result.even if you do follow this list,no promises can be made that your engine will cool well enough.there are far too many variables.experimental only! you have been warned!


required.not optional:

1.a 3g alternator.

mid '92-94 idi:
if your '92 was mid year,and came with the updated serpentine belt,you already have the upgraded 130a 3g alternator.all '93 and '94 idi's also have the serp belt/130a 3g.skip to #2.

1983-92
the 3g replaced the older 1g alts from the factory on this engine,mid year of 1992.if your '92 idi has v-belts still,it's got the older alt.you'll need the upgrade,along with all idi's before it.if you haven't upgraded to the 3g yet,do it anyway.even if you don't install e-fans.the mod is so affordable and easy to do, there is no reason an idi isn't sporting a 3g today.major upgrade for so little money and effort.you don't need new.salvage yards are your friend.these alts last a long time.

start by learning here:
3G alternator FACTS (its wins again!)

& youtube vid for more tips/details:
http://www.youtube.com/watch?v=eeolsEvzqz4


2.engine coolant temp gauge.that stock idiot light in the shape of a gauge will not do.stick with a good,well known quality gauge.if you try and alter with an unknown,or skimp on price,you'll just be sorry.expect to pay right around 50 bucks at least for a well known trusted gauge for accuracy.

3.two electric fans,known to last and supply enough air to cool this engine.one will not cut the mustard.
i use the 95-98 dual ford windstar assembly.many report the fans found on 3.8l v6 cars of the 90's work very well also when paired into a custom built dual assembly.

4.proper controller and wiring to handle the load of the dual fan setup.for those with a/c,this means a controller which turns the fans on at least low to mid speed when the a/c is turned on.otherwise you could burn out your compressor.
alternatively but not suggested,would be relays and switches to control them manually.
i use delta controls #FK-85
Constant Temperature Controllers and Accessories
caution! small one man show,as far as i can tell.likely not his primary job.you know how this can be.
Brain is the name,and top quality seems to be his game.so if you can order ahead of time,with expecting to wait upwards of over a month,it's worth the wait.other controllers made by large manufacturers have variable rate controllers or more basic on/off style if you'd rather and need the parts much quicker.

5.properly kept fresh low silicate coolant mixed exactly 50/50 with distilled water and with proper levels of sca's.

a.proper coolant for the idi.example:
Fleet Charge Specifications Sheet
needs to be checked and maintained with liquid sca's or via loaded coolant filter periodically.as with any coolant that can technically be used with the idi.
ELC coolant = ford and international both say NO!
evens waterless = yes,but pricey.

b.antifreeze tester.sold at any local auto store.insures your coolant is clean,mixed correctly for 50/50.example:
Amazon.com: Prestone AF1420 Professional Antifreeze / Coolant Tester: Automotive


c.sca test strips.example:
New Pack of 25 Penray 3 Way Heavy Duty Antifreeze Coolant Test Strips | eBay

6.13 lb radiator cap.example:
Stant 10329 Lev-R-Vent Radiator Cap - 13 PSI : Amazon.com : Automotive

only one exemption:
zero pressure cap with evens.
otherwise 13 lb only.

7.motorcraft t-stat.the updated part number is RT1049 exactly/only:
Motorcraft RT1049 190F and 88C Thermostat : Amazon.com : Automotive
(specs are incorrectly listed.trivial.it's really 192 degree.not 190 as listed on amazon.the part is 100% correct.)

8.diesel specific sized radiator of course,with at least 3 cores.fins per square inch count is probably more important to focus on,rather than copper/brass vs aluminum.
start with an old,half plugged radiator,then your doomed from the start.clean or replace it first.

9.optional,but highly recommended; coolant filter.examples:
http://www.ford-trucks.com/forums/1060051-coolant-system-filtering.html?highlight=coolant+filter

finally,how difficult is the conversion?

if you have basic average shade tree mechanic abilities,a touch of fabricating skills,can follow a basic wiring diagram,it's actually a very easy mod.easier in fact than swapping to hydroboost brakes from vac assist,and that's a fairly simple swap.about as time consuming as well.give yourself 4 solid hours for everything,start to finish.
on a difficulty scale from 1-10 with 1 being easiest,and 10 hardest.i personally ranked it a 2 for my radiator size,e-fan assembly and controller used.


here is my setup.mostly with dated pics,but the fan assembly remains unchanged.
1995 - 1998 Dual Electric Ford Windstar Engine Fan Assembly.Approx 2200 CFM Each/4400 CFM Total
Delta Current Control Variable Speed Fan Controller #FK-85P w/ DCC Remote Temperature Controller #TADJ22 & Indicator Light #L-101
(Normal Operating Temp of the IDI Diesel: 195° - 237°F)

the windstar cooling fan assembly was just about a direct bolt in fit.a little shaving of some plastic here and there,and self tapping screws is all that's required on 3 corners.
the upper pass side,simply took a threaded rod,or long bolt i guess it was,and just some extra nuts to hold it where you need it.very basic and easy.just make sure the fans don't rub the rad fins.my truck uses the taller radiator with a/c.
it is a replacement radiator.i went with another copper/brass unit.many prefer aluminum.





most current pics:




you may be thinking at this point,it would be a great mod to do, due to all the pro's,but find yourself thinking,well he must have just a hwy cruiser or something.it's not anything you could do to a truck that gets used for work.
my truck is used 100% for work.
here are some of it's normal activities.keep in mind,this truck tips the certified scales at over 8k lbs empty.







......................................
electric cooling fans , ford windstar cooling fan assembly , ford taurus electric fans , 3.8l , dual e-fan assembly , fan controller , performance mods , economy increase , efficiency , free hp , hp gain , fan delete , operating temp , save fuel
mpg mods , hypermilling / hypermilers tweaks , overheating , failed fan clutch , 3g alternator , destroyed radiator


this conversion was performed in January of 2011
either plowing or towing with the truck and dump trailer loaded at or close to max GCVWR the truck has never in it's history overheated.

Nice write-up! I think I will eventually do this; too bad I junked a Windstar about 5 years ago

I really like that DCC fan controller

Thanks for the write up.

Nice concise information well laid out.

I'm sold already and just have to get some more materials prior to my launching my TECH 101 on my setup.

Biggest needed item right now, is a very hi quality affordable controller!

Also a real temp gauge is a big part of the required conversion. I'm still on the hunt!

Lastly the custom shroud I'm slow to build!

Again extremely nice write up with a ton of info Thanks!

dude thanks!

Great post! I will possibly go to a electric fan setup when I do the motor swap and this post will be very helpful!

Some more info that could be useful. As mentioned in the above posts, you have the choice of '98-down and '99-up Windstar assemblies, both of which will bolt up about the same way. The '98-down assembly is quite easy to remove in a U-Pull-It yard as the whole top of that Windstar core support unbolts, you're looking at a bunch of bolts with 8mm and 10mm heads there. The '99-up core support on the other hand does not come apart like that, so for ease of fan assembly removal you may want to enlist the services of a cordless sawzall, a sharp hacksaw, or a friend with strong teeth - either way you go about, chewing thru the rad support and subsequently removing its top piece will make your mission much easier to accomplish. Additionally, there is one very important engineering difference between the two fan assemblies:

The '98-down assemblies have connector for the high-flow fan come out the side of the motor towards its very rear - tho not too clear, you can see the geometry of it in the installed picture FordF250XLT provided. This appears to work decent with the serpentine-belt IDI setup, bit too close for comfort IMHO, but whatever, if it clears it clears. However in a V-belt truck, especially one with dual PS belts (one of the two factory non-A/C routings), the fan motor harness may very well end up interfering with the belts.

On the '99-up fans the connector comes out the large motor straight back towards the engine - in a serpentine-belt truck this may not clear the belt tensioners, but in a V-belt truck with factory belts routing (no extra idlers in the vicinity) this connector arrangement could be used to keep the harness closer to the fan motor body and thus further away from the V-belts running essentially all around it - basically you will bend the wires 180 degrees right after they exit the connector and point them forward at the shroud, then run them along the fan motor body (and zip-tie them to it as a good measure) till they reach the shroud, and from there you route them any which way you please as long as it's not back towards the belts again

And whichever assembly you get, if clearances don't quite pan out during a factory-Windstar-like install (big motor on driver side, pancake on the passenger side), you can always try flipping the assembly over so the high-flow fan with the large motor ends up on the passenger side. Personal experience says a '98-down assembly flipped over in a V-belt truck has about an inch of clearance between the side of the fan motor housing and the water pump pulley and belts, behind the fan motor and in front of the accessories drive there is even more space (roomy enough to fit a standard 6-rib serpentine belt idler pulley to help with the notorious alternator belt slap at idle).

Now to take things into a bit different direction - if a custom controller like the DCC one is NOT going to be used, it's a good idea to take the time to get the fans wiring from the donor Windstar all the way to their relay box, also get the box obviously. The unpleasant part of that involves removal of the Windstar air box (majorly annoying moment) and also opening the bottom of the power distribution center and unraveling the two-inches-thick main harness running thru it - well you don't necessarily have to do that, but it's worth it as it it minimizes the amount of splicing you'll have to do later on, especially on the high-flow fan power wire. The fan relays box itself is a small stand-alone box that contains one 30-amp relay and one 60-amp relay, it's bolted either to the strut tower of the van or next to the power distribution center, kinda hard to miss.

From the factory both fans power feeds are spliced together (meaning either both run or both don't run), and the 60-amp relay is actually their high speed power supply. The low speed is achieved thru a ceramic resistor wired in between the fan assembly and the low-speed relay - the 30-amp relay in the 2-relay box may or may not actually be said low-speed relay, but the dropping resistor is located clear across the engine bay from there, under the passenger-side headlamp assembly. The simpler way to wire up the fans is to separate their power feeds, leave the 60-amp relay to power just the high-flow fan, and then retask the 30-amp relay to power the low-flow fan directly without a dropping resistor inline (you can also replace it with a 40-amp unit at the same time, for a peace of mind). Separating the power feeds like that gives you three cooling settings: low with just the low-flow fan on, medium with just the high-flow fan on, and high with both fans running full speed. How you control them is up to you, a pair of temperature sensors grounding the trigger circuits to the fan relays is simple and easy enough.

Why hasn't this made it to the Tech section yet? I vote it gets moved.

Thanks for putting this together.