I decided to do an electric fan conversion on my truck this weekend. All went well and seems to be cooling just as good as the stock clutch fan did. I will find out tomorrow if everything will stay cool. After getting everything hooked up I went for a drive with the A/C on and then parked with the engine running for approx. 15 minutes and the temp. gauge stayed just below the midway point. Total cost was right at $100 for a 16" fan and an electric t-stat. I had also bought a 10" fan for a dual fan set up but forgot that I would have to drop the front bumper in order to pull the grill to install the fan. If the single fan set up works out then I'll take the other fan back. The t-stat I bought is set up for dual fans. It took close to 3 hours, a couple beers, a pack of smokes, some scratched up knuckles and a few choice words to install everything. Guess I have a few more items to add to the pile of parts removed from the X. Thanks to Kennedy??? for the idea to do this. I believe he was the first to do the conversion. I'll try to take some pics this week and post them.

Hmmmm, I've been thinking of the electric fan conversion too. I'm looking forward to seeing your pictures and such. Keep us posted! :)

Just out of curiousity (or rather, my igornance), what fan did you convert and what does the conversion do for you?

-Harbones

I am most interestested in how it performs under duress. In other words, how does it do when off-roading? Especeially in low range where the rpms are up but the truck isn't moving very fast. I know during engine phase I will be putting a tranny cooler with fan on the front of the truck, but I was debating whether I should put an electric fan on in place of the engine driven fan. Let me know what you find.

Harbones - :rolleyes:

OK - He is talking about the radiator fan....it pulls fresh air through the radiator to cool the engine...

A mechanical fan turns when the engine turns (A drive belt...)...so the faster the engine is running, the faster the fan blades spin, and the more air is pulled through...in addition to the air moving through the radiator from the truck going foward through the air...

When the truck is idling...and the engine rpm is slow, the fan isn't pulling much air....and it might overheat.

An electric fan pulls at the same speed, no matter what the engine is doing...so it pulls more air at slow/idle speeds...keeping the engine cooler.

An electric fan can also be dash switched, so you can turn it off on water crossings to avoid underhood splashing, etc.

Some people mount a (Pusher) electric fan on the opposite side of the mechanical (Puller) fan...so they get the benefits of both.

An electric fan w/o the mechanical fan can save gas/power too...because the drive belt power is not being drained by the mech fan anymore...

If the Elec. fan set up is sized/geared/bladed properly...there is no trade off...Cooling-wise - its all good. ...There is of course (some) extra load on the battery/alternator....a factor to worry about if you are stock alternator equipped/overloaded with offroad lights, winches, onboard coolers, airtools, etc.....;)

The problems, if they are to occur, are typically due to the fan blade design...pitch or variable pitch, swept area vs shroud overlap, etc....assuming the unit is designed for your application at all...They typically size them based upon horsepower of the intended engine to be cooled, and a diameter it has to fit within.

They cannot account for all of the rig specific variables, such as obstructions to airflow on the engine side of the flow preventing/hindering cross ventilation...or to the exterior, such as a winch blocking/hindering the intake air....so there is some trial and error involved.

The hardest trial is typically a hillclimb, or pulling a heavy load, etc...where you are working hard, under load, which makes the most heat, and going slowly, which limits the rig speed related airflow as well. (A condition where you have - The most heat to dissipate, combined with the least air to carry away the heat)

Does this help make sense of the discussions above at all?

:)

I let my truck run for about 20 minutes at idle with the A/C on this morning and the temp. gauge started getting real close to the read. I will more than likely be adding the second pusher fan this week to help compensate. Overall the single fan setup has worked well. I tend to overdue things sometimes just to be on the safe side. I have noticed a little more pick up on acceleration with the mechanical fan off. A clutch driven fan, like the X has, tends to rob alot of engine power.

Originally posted by Lance


Does this help make sense of the discussions above at all?



Wow Lance, i dont think i could have asked for a better, more detailed answer. Thanks :frog:!

Not to be a prick, but I though I'd throw this in since it is the topic of a couple of off-road mags this month. They found that NOTHING made a difference except changing from coolant/antifreeze to straight water (no, they did not recommend doing this due to the obvious problems associated with straight water)!!!!!

They changed from mechanical to electric, tried different types of mechanical fans different types of coolants.

They did NOT try adding an accessory engine oil cooler (which I think would have helped greatly)

See Petersen's 4Wheel October 2001 (it has "ULTIMATE ADVENTURE" on the cover).

Without reading the article...I can say there must have been one of the limiting factors I mentioned (Or skipped/didn't think of...) going on. I have way too much evidence to the contrary.

My off hand guess is that IF NONE of the mods worked ...it was most likely that the airflow was blocked, either on the way in (Less likely, or they would have noticed/corrected for it first...), or on the way out of the engine compartment....that's about the most likely thing to negate ALL of the mods except plain water...because that's the only one that should work by itself independantly of airflow, at least somewhat.

If the airflow is hitting the radiator like a wall, because there is no where for it to go on the other side, then THAT's the only thing you might have to fix. Once you have a clear path for the flow through the radiator...then the other mods can work. (Same applies if they had a winch in front, or a plow, etc...for those...an air dam/sploiler to force air around the obstruction and into the radiator face can help)

Adding radiator fans that are working against dead air space will prove futile.

To get the air out of the engine compartment...take out/vent the sidewalls of the inner fenders and or vent/louver the hood, trim the bottom of the bulkhead/firewall and or mount a puller fan to the back of that engine pointing down, and or up through the hood, whatever path(s) you make to get flow out of the engine compartment. (Vents/louvers alone are usually all you'd need)

....There are alot of variables to eliminate....but it sounds like a blocked air flow problem so far (My best guess)


Otherwise, its like having a car with no spark plugs, boring it over, adding fuel injection, a super charger, lower gears, Nitrous Injection, etc...and then reporting that NONE of them improved the zero to sixty times.... ;)


So - Make an idiot of me...did they say what they did to finally cool it down? (Something I didn't think of I'm sure...) :rolleyes:

Well, I'm not much a Jeep expert, but I think they had a "Flat Fender" Jeep with a huge motor in it. They probably had the most difficult task one could think of in terms of cooling. A small radiator with a "plugged" airspace as you mention. I just tought the timing of the article and your post was perfect. ....I don't know if that article is applicable to what your doing or not, just thought I'd mention it and what their findings were.

Okay, I went back and looked at the article. They origianally had an electric fan and though a mechanical fan would be better. They, in essence, reconfirm you observations. The electric cools better at low speed. The article may still be of use if people are considering changing fan blade types, water pump......that stuff will have no effect.

You can't say NO effect....every cooling problem has a cause...each cause has its own cures.

If your water pump is cavitating or undersized, etc...replacing it is the cure...if your thermostat is stuck/shot/wrong temperature range...replacing it is the cure...

The main concept for you to think about is what the limiting factor is. That's the one thing to change...and that may be the ONLY change worth making...even if it would have no effect on another rig.

:)

Again, don't want to flame :)
So, please don't shoot the messanger! That was their words....but they did acknowledge what you had said earlier...that there was an underlying issue of airflow through the compartment.

You have not commented on what I am considering, which is an accessory engine oil cooler. It seems like a simple install and benefits at all speed ranges?!?!?

http://www.derale.com/derale/index.html

See fan mounted oil coolers.

I didn't think you were flaming...just that you had read an article that had discussed trying to fix and airflow prob by doing every thing except the airflow prob...where they concluded that none of the mods worked...like tests saying a turbo charger won't make you go faster, but you still have no gas, with or w/o the turbo...etc. (Misleading conclusions)

Oil coolers are good if your oil is too hot. Transmission coolers are good if that oil is too hot, etc...

If the stuff isn't too hot, you won't get much bang for your buck, even if it's just one buck.

Radiators that have the tranny cooler, etc...inside them....can get real gobs of heat from even the tranny fluid, auto trannies oils are at 300ºF or so...that's a lot of heat to dissipate...if you run hot while climbing/under load...tahn that might be a worth while addition...a free standing cooler for the fluid of choice....if you don't run hot, you won't see a difference (You might FEEL more secure).

So - These things can help individual probs...but they add up, so you do what you need to....just know what you need to do first...it sounds like they just randomly tried out aftermarket accessories or something...especially as you say they think they might have had an underhood airflow problem....on a Flattie with a big V8....

(That's like Ikea saying "Some items might require assembly...")

I hope the take out the fender liners/louver the hood or something before they melt it down.

:D

Cooling is always the heat dissipation...either the coolant can't carry the load (Inadequate volume/wrong coolant, etc.), the air can't carry the load (Flow prob, etc.), or there's no transport of the load from one to the other (Fan or radiator surface area deficiencies/mineral deposits/stuck thermostat, etc.). (Examples)

So An Asbestos Free Topic....

;)

I wanted to explore the engine oil cooler a bit more. Now, the engine oil is lubricating the engine and (as I understand it) in more intimate contact with the heat producing portions of the engine than is the coolant. The coolant is run through cavities within the engine. What I'm getting at is, no matter how you remove the heat, it will benefit the engine in low speed, high demand situations. I would assume that if you remove heat by an oil cooler, you reduce the demand of the radiator overall. I think I may be off topic a bit, cuz I think your original point was to increase HP by reducing the drag of a mechanical fan with an electrical fan. I am concerned with increased demands by running (in the future) 33's, excess weight and increasingly demanding (steep) trails.
I do think you will get power benefits from your approach.

So, as you say, it really depends on what your after! :D

Atz ryt!

You can take Penicillin if you are not sick, and it probably won't do any harm....but if you have a Fungal infection, it won't do any good either.

If the engine runs in the proper heat range...you can actually sabotage it by forcing it to run too cool. The spark plugs, etc...are calibrated for a heat range...things like carbon deposits in the engine, excess HC emissions, etc...can all result from making an engine with too much cooling capacity (Like one that can never "warm up"...it can't reach operating temp)

If it ain't broke, don't fix it until it is.

;)

A couple little caveats to throw in here. The transmission cooler in the factory radiator of most cars is weak at best. If you pull trailers or drive at slower speeds at higher rpms (low range or rock crawling) a tranny cooler is a good idea. How you hose it in makes all the difference in the world to the radiator. If you put the hose on incoming line of the radiator, it will cool the tranny fluid prior to entering the radiator, hopefully reducing the temp of the coolant slightly or cutting back on the amount of heat transferred. (Keep in mind this is hypothetical. Without an engine temp gauge and a tranny temp gauge, you couldn't verify this.) If installed on the out going side, it should have no effect on coolant temp from factory.

As for engine oil coolers, that is really a matter of personal choice. It may very well make your engine last longer. But since the oil is not a primary cooling source in the motor, the effect won't be huge. You will see no performance change with any of these mods. All you will be doing is helping the motor cool more efficiently.

As for the changes based on engine temp, that is VERY true. A lot of people don't realize what effect engine temp has on an emission controlled motor. I have seen improperly gapped spark plugs cause detonation. Also, if you live in a northern climate, you don't want to cool the motor too much for obvious reasons. But keep in mind this requires dramatic changes in engine temp, say putting in a 160 degree thermostat. Simply adding a trans cooler or oil cooler won't effect this by itself. Adding electric cooling fans and stuff can dramatically effect it though. That's why I am doing engine phase (Phase 6) last. I will let everyone else guinea pig it for me so I can learn from others mistakes and successes.

You Tell'm War! :D

Follow up:
I e-mailed the mag to ask them why they didn't include an oil cooler in their article. I got an e-mail back and they stated what has already been stated here!




From: quinnelc@emapUSA.com (Cole Quinnell)
To: NED946@aol.com
CC: PeweR@emapUSA.com (Rick Pewe)



We ran an oil cooler on the Jeep previously. While not part of this testing, so we don't have solid A:B:C testing data, it did not make a noticeable difference in engine coolant temperature.

An oil cooler (or power-steering cooler) will keep that fluid cooler which, of course, is better for the engine (or power steering). However, it does not work effectively to cool the engine because the bulk of the engine heat is generated in the cylinders and around the exhaust valves in the head. These areas are surrounded by cooling passages carrying engine coolant. Even if your engine oil is 20 degrees cooler, it won't effectively lower the engine coolant temperature. Also, oil is significantly less efficient in transferring heat compared to water or 50/50 coolant and water mix. Therefore, it cannot efficiently radiate heat or transfer it to the air through a radiator.

This is a smattering of information. I hope it answers your question.

Thanks,

Cole


>>> <NED946@aol.com> 9/3/01 3:41:10 PM >>>
In your October 2001 story, "Our Trials and Errors in Improving a 4X4's
Cooling System," you conclude that in your configuration, all of your
modifications netted "no real change."
Additional cooling is something that I am currently working on (I now have
a transmission cooler and a power steering cooler) and I was contemplating a
"Derale 16 Pass 10" Reversible Turbo Fan" oil cooler. Is there a reason that
option (or similar) was not considered for your Flatfender?

Ned

Just an interesting little note. Did you know that the Cadillac Northstar motor is cooled primarily by the engine oil? It is designed so you can literally run the engine out of coolant but continue to drive. I for one wouldn't have the #$%& to test the theory out on a $45,000 car, but it is supposed to work. The block is cooled entirely by the oil. Only the heads flow coolant. Doesn't pertain to Xterras, but interesting nonetheless.

As for the mags conclusions on oil coolers, I agree totally. I know I will be adding a tranny cooler on my X, but the engine oil cooler will be left off. It's not something to worry about.

Yep.

Northstar's excepted, as a design, most people cool the oil so it stays as oil, and not to cool the engine. When the oil gets too hot, it can coke, break down (No lube...just deposits instead). As having a coke in this case is a bad thing...they want the oil to stay cool enough to avoid that.

If you use a pure synthetic (Not a blend) you avoid this altogether...they will keep working no matter how hot your engine gets.

Maybe a synthetic run Northstar in the Flattie instead of the (Mouse?/Rat?) V8 would be an improvement? ;)

Originally posted by warmonger
Just an interesting little note. Did you know that the Cadillac Northstar motor is cooled primarily by the engine oil? It is designed so you can literally run the engine out of coolant but continue to drive. I for one wouldn't have the #$%& to test the theory out on a $45,000 car, but it is supposed to work. The block is cooled entirely by the oil. Only the heads flow coolant.

I was also under the impression that when the Northstar system senses a loss of coolant the the system actualy utilizes 4 cylinders for cooling the engine with air, alternating between all 8 cylinders. I might be delusional though.

Despite the possibility that you are delusional, you are correct about the 4/4 oil/air split on limp home mode for the Northstar system...loose all the coolant, and the thing drops to a 4 cyl with air injection on the other 4.

I wonder what the system does if you loose all of the oil instead? Re-Route its ATF ? Have the On-Star call the EPA to clean it up? :bloated:

Originally posted by warmonger
Just an interesting little note. Did you know that the Cadillac Northstar motor is cooled primarily by the engine oil.

So is a Porche 911 Carrera.

My mom took hers one time (only once) to a Jiffy Lube and when they got done she asked how many quarts of oil they replaced.
--"Three. Why?"
"That's an oil-cooled engine, so it must be more than that."
--"Ma'am, cars don't need more than that."
"How many quarts did you drain?"
--"Let me check..."

Turns out they drained 16 quarts (IIRC), but the next guy only replaced 3. Needless to say my mom has since only taken it to a dealer.

Jiffy Rube....say no more

I guess I was thinking back to my 1979 Suzuki GS1000 and my Suzuki Bandit 1200S days. No coolant, just oil cooler (on the bandit) and good old air. I realize the Xterra ain't a motorcycle :) and it isn't designed to be an oil cooled engine, but I did think that removing heat would benefit overall (especially with a temp activated sandwich adaptor that won't allow oil to flow to the cooler unless over 180 degrees) especially at low speed, high temp trails.

Aircooled engines are not the best for heavy loads...they are lighter though...

I've been able to test the fan setup a little more over the past week. I noticed with only the one 16" fan that it would start to overheat when sitting idle with the A/C on. I installed a 10" pusher fan last night and everything seems to be good. I let my truck sit idle with the A/C on for about 30 minutes and it didn't get above the 1/2 way mark. A/C seems to blow a little cooler too. I gonna try and hit some trails in the next week or so and see how it does then.

Red - Suposed to get hotter this weekend too...sounds like you might be ready for it! :)

Things seem to be doing great. The temp. gauge did not move above the half way point. It's almost 90 degrees here today. I'm very happy with this mod. Seems to have a little more take off power with out the clutch fan. Gonna install a voltage gauge this evening to see if I'm pulling to much power.

Sounds like the fans are doing it for you....good idea on checking the draw...the fan motors are rated typically around 10 - 20 amps at full draw...less as they have momentum, etc...take the readings on start-up, as well as while running...makes a difference,

:)

Here's a pic of the front 10" fan.

and the puller 16" fan

Looks good Red! :D

Are you running a body lift, or is that gap in your front bumper just a testament to KMA's stellar build quality? :bonghitte

Its obviously the auxillary thermoaerodynamic exchange portal.

I'd like to see a wider angle on that photo, could you step back about 10 feet and take a new pic? I've never seen that bumper before.:eek:

I'll post the pics in a new thread. Don't want this one to get to far off topic.

I have the Flex-a-Lite Black Magic 150 electric fan installed on my X and it runs just a tad cooler than normal in everyday driving, I can let the truck idle with the air on all day long and it runs below half. Now I have had a cooling problem since day one with my truck that Nissan can't seem to fix, I thought this would help and while it runs cooler day to day my truck ran hot a few times at GOX. After talking with another X owner at GOX that has had the same exact symptoms I believe the thermostat is the problem, I just can't believe Nissan would overlook this simple change. Watching my temp guage it makes sense, when running hot it will then drop 3 needle widths all at once then do this again then again until it is running normal again....not a smooth progression of cooling. I am going to change the thermostat and hopefully this clears up the problem, I doubt Nissan would touch the truck with the electric fan now so I will take care of it myself...anyone know of a hi-flow thermostat made for Nissan's?

BTW: I gained a good bit of power from the electric fan, on the way to my shop is mostly hills forcing me to downshift to climb them...now I can pass people in 5th on all but one hill now.

If the thermostat sticks, the radiator can explode. This happened to me...

Ruined a weekend wheeling trip...exploded out on a trail.

For the few bucks a new one costs....worth every penny!

(I was covered by warrenty...but you're right...they'd blame it on your new fan for sure)

Good Luck!

:)

Hopefully tomorrow I will replace it and that fixes the problem....now I never even looked but I thought I heard that the thermostat placement on the 3.3L motor sucks. Lance are you part of MAXC?

I might be....too many acronyms...I forget after a while. :bloated:


I haven't gone anywhere with them yet at least.

Are you?

Yep, actually a founding member along with Philosopher(Mr T), Synchro and Pikachu. We got to get together for some wheeling soon, we are only about an hour from each other.

Where in NJ are you?

I'm in Lawrenceville...next to Trenton/Princeton/West Windsor areas.

Maybe we could hook up some time?

Yeah, sounds like a PITA Todd. Here's the ESM description...
1. Drain engine coolant from drain plugs on radiator.
2. Remove radiator hoses (upper and lower) and fan shroud.
3. Remove drive belts.
4. Remove pulley bracket. (the black one across the upper front of engine - Brent)
5. Remove water inlet and thermostat assembly.

ugh,
Brent

Originally posted by Lance
Where in NJ are you?

I'm in Lawrenceville...next to Trenton/Princeton/West Windsor areas.

Maybe we could hook up some time?


Pretty small world, that's where my lady is from. :)

Originally posted by OffroadX
Yeah, sounds like a PITA Todd. Here's the ESM description...
1. Drain engine coolant from drain plugs on radiator.
2. Remove radiator hoses (upper and lower) and fan shroud.
3. Remove drive belts.
4. Remove pulley bracket. (the black one across the upper front of engine - Brent)
5. Remove water inlet and thermostat assembly.

ugh,
Brent

I checked that out myself, it does sound like a pain in the ass. I will be tackling this within the next few days so if I come up with a shortcut I will let everyone know.