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Aftermarket fan blade (direct drive)?

Runnin'OnEmpty

NAXJA Forum User
Location
Southeast USA
What about replacing the radiator fan blade and clutch with
an aftermarket direct-drive fan? Since the stock clutch runs
at about 80% shaft RPM at full engagement and a direct-drive
fan would run at 100%, it might be more efficient???

(In searching, nothing turned up. Just wondered if anyone had
tried this to solve our overheating issues?)
 
I’ve heard of ZJ clutch fans being an upgrade? Can’t vouch for it though... good vents, aftermarket pump and radiator, and I’ve had good luck with the purple ICE additive made by royal purple..

Interested to see what replies you get thi
 
Overall it's considered a bad idea on a 4wd specially it you do any water crossings.
 
A direct drive fan is less efficient. It take HP to turn the fan, when it is not needed or only partially needed, a fan clutch reduces the power necessary to spin the fan.

Some people say that installing a Ford Explorer plastic 11 blade fan moves more CFM's. The 7 blade XJ HD cooling fan was discontinued long ago.


Overheating is usually never caused by one single faulty component, it is usually caused by lack of routine cooling system maintenance leading to numerous weak or worn out cooling parts.
 
Usually, maybe. But in my case everything is new dealer except the radiator which is Spectra. No rust, scale, or anything behind water pump and T stat housing. Still tries to overheat until aux fan kicks on at 220. Can't run a/c or it does overheat unless moving at a decent speed and not uphills. I am pretty much convinced it's a lack of airflow from clutch fan at low rpm/idle. Clutch is new dealer and does lockup as you can hear the fan change pitch it just doesn't move enough air. This is a stock Jeep, not lifted. No tranny cooler in front of radiator.
 
Maybe you have a bad tstat? Ive seen "new" out of the box not open when it was supposed to
 
It runs right around 200 all other times except in traffic, drive throughs, or low rpm operation like climbing a hill going slow, worse with a/c all the new parts improved cooling zero percent over the old parts, so hundreds of $$$ down the drain for nothing
 
Over heating in the drive-thru, in stop-n-go traffic, or on the 4x4 trails is a primary symptom of a faulty mechanical fan clutch.

XJ 4.0L run about 195*-210* and the e-fan turns on at about 218-220*. I have had crappy thermostats that were lazy about opening fully, or only lasted a year or two.

A 4 cylinder Cherokee fan clutch engages sooner and spins faster that the stock 4.0L clutch. You just have to be very sure it fits with enough clearance and the the motor mounts are fresh.
 
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It's a new dealer clutch, that you can hear when it's engaged at higher speeds, when it's hot it doesn't even make 1 revolution when you spin it. Not that that means it's good. Maybe the 1 core Spectra is not shedding enough heat to activate the thermal part of the fan at low speeds or idling in traffic. I even modified the shroud so more of the blades are surrounded, like they should be.
 
220* is not overheating if the e-fan comes on and the temps go down. I prefer a two core radiator.
 
220 is not overheat but if I can't run the a/c at the same time or it boils over, completely filling the reservoir and puking on the ground. It should be able to run without the aux fan coming on at all, with a/c off, as it's a backup. Yes, I have pressure tested the 16 lbs cap and an 18lbs cap. Still does it.
 
I know mine, with the 4 banger clutch and a 195 t-stats...runs 200-205 deg with the A/C on in traffic....

and my stuff is old....trans cooler in front of the radiator, as well as an A/C condenser...
 
Something is still amiss. The 4 banger clutch from Napa slowed the heating to 220 but only by a few minutes. A/C is still a no go as it goes to and above 220. Now to think about an electric fan from something. I cannot find the taurus fan anymore. Volvo fans with the curved style blades are non existent. Do the Volvo square blade style work as good?
 
So, I am noticing that the electric fan pulls more at idle, based on feeling the front side of radiator/condenser.

Start your own thread and list the year and what you have done along with parts (brand/model) you used. How long have you had this XJ?
 
.......... I even modified the shroud so more of the blades are surrounded, like they should be.
I noticed this myself; it looks like the entire driver's side of the
shroud is cut out, allowing loss of suction through the radiator core.
In fact, seeing that is what got me to thinking about a direct-drive fan.

I'm thinking about one of those glass-filled composite fans such as
Flex-A-Lite sells. They weigh as little as 11 ounces, and flatten out at
higher RPM. The lighter weight alone should reduce the horsepower
required to spin it.
 
I've seen those used in the muscle car world. They make a ton of noise. Not sure how they function but they are loud. I think the biggest issue with replacement radiator is the loose fin per inch count. The true oe radiator have a denser fin count than part store or even deal replacement radiators. I noticed this on my 89 Caprice with the 5.7, 02 PT cruiser, and others. I even purchased the radiator from the dealer for the pt cruiser and it had 2-3 find per inch less at the minimum than the factory radiator. My Caprice had the densest fin count I've ever seen. Even used it in my 70 Chevelle with a built Sbc and no shroud and never came close to 200 in stop and go traffic on 90 degree days.
 
If you add or replace the AUX fan, go with the newer model fan with the Simitar shaped blades. It move a lot more air.

Excess heat can also come from cooling the transmission. Double check that your torque converter is actually locking up. If it doesn't, the transmission generates a lot more heat.

Do Not raise the back of the hood for highway use, it makes it worse. Most hood vents do their best at rock crawling speeds, not highway speeds.
 
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