Cooling fan upgrade comparison: Explorer 11-blade fan and HD clutch versus SPAL 19" 850-watt electric brushless fan
- Thread starter Steel City 06
- Start date
The specific radiator is important, and why I asked. All the fan in the world won't overcome a radiator without enough cooling capacity.
Did you do the 6.1 conversion? Do you happen to know the specific radiator, or the specs?
the conversion was done in Dubai by previous owner. so i don't know the specific radiator. It was leaking when i got it, so i had it serviced at a local cooler specialist, he added a thicker core. the currently installed fan isn't very powerful but it will drive fine without overheating even with heat and A/C on. just on slow continuous uphills, ECT will push towards 230, so i think a more powerful fan will make a difference
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I think you can manipulate the lower and upper limit settings with the temp tied to the outlet ECT sensor to make it ramp up any way you want. With the Zener on, I have Low set and 160, High at 190 now and it was fine in all conditions in very hot weather with a modified 4.0L. You could do low at 150 with the Zener referenced in this thread which would make the fan run quite a bit faster on idle and still max at 190 outlet. Assuming your 6.1L is designed to run at 195F. If your motor runs a cooler thermostat, then you could move both temps down in the correct bands spaced like this.
On the drive home at 80mph (130kph) climbing up the Colorado mountains it ran a little hotter (208F) but this is due to the high speed airflow issues under the hood inherent with the TJ. I wasn't capping out the radiator's ability to reject heat, but with the higher rpm at this power output, the high pressure behind the radiator reduces the flow of air through the radiator even with the factory shroud in place.
I've thought pretty hard about how to extend some paneling under the leading edge of the frame to force an area of low pressure behind the radiator as modern cars do. The steering box/trackbar position and upper control arm paths really limit the options to do much with this.
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I can confirm that highway flow issue. I've tested this on my rig - which puts out a crazy amount of heat. Running down the highway at 70, if I turn off my electric fan, it heats up very quickly - to the point that if I continued it would overheat. Turn the fan back on, and it cools down also quickly.
Is it a downflow or crossflow type radiator? Do you have a fan shroud installed?
Looking at your other post you say it's a fan from a 05/06 Wrangler. Do you have enough room for a mechanical fan instead of a electrical fan?
I started off with a SPAL 300 watt fan on my setup but would overheat occasionally so took a chance and swapped out to a mechanical fan. So far it seems to be doing the trick. Even while in UT @ Sand Hollow when temps were 90* or higher I only got up to 230* once and was able to cool it back down by reving the engine some.
Do you have a crossflow or downflow type radiator?
I tried some 4-Lo + 2-Hi <15mph driving with the upper limit set at 230, 260 and 190 for prolonged driving (multiple hours) with outside temp reporting 95-104.
At the lower (added) ECT max set at 230 I was seeing factory upper inlet ECT temps off ODBII live data of 210-212 F.
At the lower (added) ECT max set at 260 I was seeing factory upper inlet ECT temps off ODBII live data 210-214, peaking for a bit to 224 F. Not overheating, but hotter than I would prefer. I measured the exterior of the radiator outlet aluminum insert at this point and it was coming back at 174F.
At the lower (added) ECT max set at 190 I was seeing factory upper inlet ECT temps off ODBII live data 199-203 F. I decided to stick with this upper limit.
With the engine very hot (ODBII live data = 215F) and idling tried 210 and 200. I didn't drive at these speeds, but the upper set at these speeds, the fan speed goes down alot compared with the operating speed at 190F, but also brought down the engine temp quickly.
Photo for reference on the TJ 4.0L while setting up the wiring and coolant hose. This is the added radiator outlet ECT sensor location and the aluminum coupling where I measured the outlet coolant temp with IR thermometer.
At the lower (added) ECT max set at 230 I was seeing factory upper inlet ECT temps off ODBII live data of 210-212 F.
At the lower (added) ECT max set at 260 I was seeing factory upper inlet ECT temps off ODBII live data 210-214, peaking for a bit to 224 F. Not overheating, but hotter than I would prefer. I measured the exterior of the radiator outlet aluminum insert at this point and it was coming back at 174F.
At the lower (added) ECT max set at 190 I was seeing factory upper inlet ECT temps off ODBII live data 199-203 F. I decided to stick with this upper limit.
With the engine very hot (ODBII live data = 215F) and idling tried 210 and 200. I didn't drive at these speeds, but the upper set at these speeds, the fan speed goes down alot compared with the operating speed at 190F, but also brought down the engine temp quickly.
Photo for reference on the TJ 4.0L while setting up the wiring and coolant hose. This is the added radiator outlet ECT sensor location and the aluminum coupling where I measured the outlet coolant temp with IR thermometer.
upper and lower hose are both on passenger side, so that means downflow i would think. and yes Mopar 55037694AB is a fan shroud combination.
That is determined by the direction of the tubes/tanks. You can have both hoses on the passenger side with a double pass radiator if the tubes are horizontal. If the tubes are vertical and tanks at top and bottom, you have a downflow radiator.
A downflow radiator has a tank on the bottom and one on the top of the core where a crossflow has a tank on each side of the core.
Crossflow radiator
Downflow radiator
The fan you are using was designed for the 2.4 four cylinder engine so I would wonder if it doesn't have enough capacity to properly cool your Hemi...
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thanks for explaining down/crossflow. will check next time i open the hood 
thanks for explaining down/crossflow. will check next time i open the hood
It's why we're here... To help each other out when we can....
Since your radiator has the inlet and outlet both on one side from what I know that would be a radiator normally made for a LS swap. And again not that I'm an expert on this but from all the LS swap type radiators I've seen have all been a crossflow type radiator.
The two radiators I posted above are what are referred to as a SBC (Small Block Chevy) V-8 swap radiator where the upper outlet is on the passenger side and the lower outlet is on the drivers side. This type of setup works with "some" Chevy & Mopar engines.
I have a 2003 Dodge truck engine so this configuration works for me but some Hemi engines have the inlet & outlets both on the drivers side.
Good to see someone's putting it to the test.
Out of curiosity, did it ever actually reach full power on its own accord? In all of my driving I have never actually had the fan ramp up to full power on its own, perhaps 80% of max speed for a few brief periods (after a couple minutes of full throttle and 4,000+ RPM plus AC).
There's definitely some more reserve capacity left in it no matter how hard I've ran it.
A sufficiently large mechanical fan will definitely outperform any electric fan at most cruising RPM ranges. Really the only point where an electric fan beats a mechanical fan in terms of performance (ignoring efficiency) is that it can go to max speed even with the engine at idle, whereas the mechanical fan might only be spinning a quarter of that speed.
Really I think why the Camaro SPAL fan shines where so many other fans suck (or don't suck, I guess) is because the Camaro fan is about the same diameter as a mechanical fan. Even if we artificially limited the Camaro fan to 300W or less, it would probably still curb stomp most smaller electric fans just because airflow is proportional to the cube of fan diameter. Sure, wattage goes up by the sursolid of fan diameter, but that is more than made up by the lower shaft speed requirements, given shaft power is proportional to the cube of speed.
I don't think so, but don't know for sure. With the sound deadening I've done under hood and in the cab, the only way I could hear it at any speed it ran was with the windows down or standing next to it. I need to get the formula for the temp signal from the Lingenfelter module setup in my HPTuners to know what temp it thinks it is. But I'm busy with some other problems and the fan is working extremely well.
I really don't have an apples to apples comparison at speed either. Before the electric fan I was running an old thermostat original since 04 that was staying open with temps down at 190F. And lower compression. And iron TUPY head. I didn't do the fan mod in a vacuum. And the combined effect was very positive.
I have at least the formula for a HPTuners custom field to get the ECT reading.
1/ 0.0142857143 + 0
The results seemed valid. The diode obviously distorts the actual reading, but I haven't thoroughly checked how across the curve.
Wish I was having as much luck figuring out a small exhaust leak in my new cat system tonight.
1/ 0.0142857143 + 0
The results seemed valid. The diode obviously distorts the actual reading, but I haven't thoroughly checked how across the curve.
Wish I was having as much luck figuring out a small exhaust leak in my new cat system tonight.
this is my radiator, tanks are at top and bottom so that would make it a downflow. the truck was running like that in dubai, with the 2.4 l jeep fan in heat and a/c without overheating. here in austria it gets on the hot side when driving long mountain passes. so hence the upgrade. no mountains in dubai ;-)
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FYSA was replacing the radiator in my wife's 2013 JK and had the electric fan out...and had my old TJ radiator...so a unique opportunity to see what fits...a little clearancing for the top and bottom hoses and it's almost an exact match.
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