You can keep the plastic clutch fan blade and add a water pump hub extension. Usually called a series 80 hub Assembly in some vehicles. This way you get a more aggressive fan blade angle, more CFM's, a much lighter fan blade. The closer your fam is to the radiator and futher in your fan shroud, the more air it will pull through the radiator and potentially AC condenser/PS cooler. The lighter the fan blade the faster it can turn with the water pump and the less static resistance on the drive belt. There is a parasitic draw on the engine from adding A heavy fan blade. My WJ Mopar blade is 16 Lbs and the Dorman 620-155 plastic 11 fan blade i use is 3.3 Lbs and pulls 2x as much air and 1/3 the resistance on the engine so there is much less HP loss and loss of MPG. The Mopar 7 metal blade added a 10HP loss. The Dorman Plastic 11 blade only had a 2HP loss. 1/4.8 of the OE fan blade!
So yes, the ford fan does bolt right up to the Jeep fan clutch. From my understanding it does work well, but it also wears the Jeep fan clutch out a lot faster. Which, I could see since the Jeep fan clutch isn't designed to carry the load of the ford fan clutch. I not positive on all of that, but it makes sense in my mind some how. Long story short, if Jeeps are getting hot, the cooling system needs to be looked into. They should run just fine on factory cooling components.
@@EmbarkWithMark Yes I think so as well. My 03" 4.0 TJ has never been able to hold the AC in hot temps. A electric fan does real well but makes you overheat doing hyway speeds. The only real mod that can help maybe a little is the 93' fan according to others who have modded. But they are not clear on whether they are cooling in mild heat or full on 100F temps with the AC. I have wheeled in over 110F temps with full AC and can get cold air if I give the stock fan 2000 rpm while sitting. But 110+ temps are probably not a smart off roading situation. I'm told "hell no. I'll wait till the temps are milder". Anymore I join in with the AC at home crowd at 100F outside.🤣
Definitely keeping my eye on this experiment. My LJ stays at 200-210 most of the time unless I’m driving up the 395 in the middle of summer. I have Metalcloak fenders with the louvers behind the front wheels which I think really helps keep the temps down. My next step will be to remove the hood insulation and maybe do a louver kit for the hood. I think the stock cooling system is up to the job for the most part so I don’t see changing out anything there.
Interesting. I know of a few close friends who have done hood louvers. It helped with engine bay temp but they claim it did not affect there engine temps. Honestly this confuses me a little. As long as all the components are factory mopar parts and in good health you should be fine. I’m going to continue diagnosing the system. I’m determined to figure out the cause. Hopefully by working on each section at a time I can save someone else time, frustration, and money. Thank you for your information!
Embark With Mark Yeah, that’s my mindset when it comes to parts as well. I like using the factory components when I can. Thankfully I’ve had little trouble with my LJ so I haven’t had to do much. I do think that anything that can be done to remove heat from the engine bay is a good thing. Whether that’s louvers, vented fenders, or something else getting that heat out is a good thing. When I installed the Metalcloak fenders I noticed my temp dropped about 10 degrees on the road. On the trail you can stick your hand near the louver and feel the heat coming out. A few weeks back I had my first heat soak issue. We were climbing up Sherman Pass road out of Kernville and it was over 100 in the river valley. After we stopped at the trailhead to air down and I started the rig back up it was spitting and sputtering for about 20 seconds. It cleaned up after that and I had no other issues on the trip. Jeeps are never boring that’s for sure!
I changed my stock Mopar water pump when water started leaking from the weep hole to a Flowkooler water pump that supposed to pump more effectively and cool the engine, added a new 18psi cap and a new 185 degree thermostat and it didn’t do squat.
Yea, that is what I am finding out. I already new a low degree thermostat would not do much as the Tjs are designed to run at 210. But It is interesting to hear that "better" water pumps are not doing anything to help the issue. I am going to make this a series and go through each cooling system component to find the issue. Hopefully others will be able to learn from it and save some frustration,time, and money in the process.
The Interesting part is that I have access to a 100% stock 2004 rubicon. That Jeep can idle in 110+ heat with ac on and never go above 208. In fact it cycles between 201 and 208. My point is, is that I feel as though those mods should not be a requirement. But I may look to that in the future. To the point with the Jeep fan clutch running a ford fan. The clutch is not strong enough to handle the resistance and will fail. It’s been documented so I feel it isn’t worth while burning up a perfectly new mopar fan clutch. I’m going to continue my search for what the cause of the temperature difference is. I’ll be sure to document my path. I hope it helps someone in the future! Lol.
I use a severe duty clutch from a dodge application. Bolts in. The new clutch cools the coolant much faster than the old one but still gets to hot I feel like. Wish we could modify them to come on at a lower temp. You should measure at what temp the clutch engages. Also I think your radiator isn’t cooling as efficiently as maybe it once did when new. What temp does your thermostat open? Does a lower temp thermostat keep it cooler? Let’s get into the tech bro!
You can modify the fan clutches to lock earlier. You take that metal coil on front and tighten it up a few turns. The radiator is a thought, though it is only a year old. A lower thermostat will not work correctly because the engine is designed to run near 210 by installing a lower temp thermostat all i would be doing is making the computer run in a "warm up" stage longer. Thermostats do not effect the cooling efficient of the system as long as they work correctly. With all that being said, I'm thinking maybe something is plugged. I can confirm that the system should need no modification I have access to a 2004 Rubicon that is 100% stock. The hottest it will run is 207 and that is with the AC and in 110+ heat. So, something else is going on here. I am going to keep digging in here till I figure the issue out. Check out the playlist th-cam.com/play/PLjcr5-AqFV1G7jYXYGUt0HkkTyRoV5L_D.html to see what I have done thus far. Tell me more about your Jeep and its issue with running hot.
@@EmbarkWithMarkdid you recently change coolant? Could be air in the system. But also likely the radiator has a few channels blocked with sludge. Do not do a chemical flush, you risk clogging up more. Take radiator off and flush with pressurized distilled water. You can even use an attachment on cap to add air compressor pressure to the system to push clean water through it without causing calcium deposits.
I think the original metal fan blade is heavier than the Ford plastic one I don't think there's going to be any problem with the fan clutch handling it
Dimensionally it will bolt it. The ford fan is the same radius as the TJ fan. That’s why it can be used. However the TJ fan clutch internals can not support the extra load the ford fan will place on it. It will work. But the load will just wear out a perfectly functioning fan clutch.
Well, that settles that. I was actually looking at a Ranger severe duty clutch and fan. I think you suffer from the same as i do at idle. Just need more air flow at idle. Need a clutch that would engage and rotate the fan like 90% of pump speed. Im pondering trying modifying the steel jeep fan to fit the Ranger severe duty clutch. Got to be a solution. As for the water pump I had a Flowkooler pump on mine and it clearly caused the motor to get warm at speeds when ambient temperature was high. Put stock type water pump on and temps at speed are much better.
That would be a Interesting idea. I’m not sure it’s an air flow issue anymore. I’m thinking there is an issue somewhere else. But I’ll be going through each cooling part and analyzing it. Hopefully I come to a conclusion. I’ll be making a video for each part I do so that hopefully it helps people to save some money, time, and frustration.
I’m not sure that will work honestly. I think there is more to. An engineer I know explained that more blades at not always better. Sometimes more blades are less effective because each blade grabs less air. It could be the way the ford clutch locks up too. What I can tell you is I gained about 2mpg by going back to the factory setup. I just don’t think it’s worth the money. I’m exploring other options. Other videos are to come diving deep into this issue.
From what I understand is the 4.7 had a second fan option that was an electric and mechanical fan coupled together. Now I’m not sure you could only run the stock mechanical fan, but I do know that a ford 5.0 fan and clutch works very well on the 4.7s.
Funny I am just now seeing these newer videos of yours - That's awesome you tried the experiment again with the Ford 11-blade fan. Few things I want to mention... I've never seemed to get 100% accurate results with my anemometer. One day, I could measure it at full temperature and get 5.7 MPH, while the next day, I could get close to 7MPH. I think surrounding winds (even the slightest breeze) could affect those numbers, and maybe even barometric pressure. As far as the fan clutches go, both of those units you have there are aftermarket Hayden severe duty units. You could mount the Ford fan to the clutch for your stock fan, and it would work... however I believe the size of the center hole and bolt holes, are different. As for your Jeep getting hot even with the Explorer fan, I have to wonder if there's something going on with your Jeep's radiator. Has it been replaced? There could be some gunk in there plugging some of the passage ways. It's possible since your heater seems to bring it right back down. I've seen a lot of people trying Explorer fans on various Jeeps that had a 5-blade fan stock... some get better results, others like you, didn't. I still run a modified 11-blade Explorer fan on my Grand Cherokee 5.2L V8. I had to replace the fan clutch with another one in 2019 because it started not wanting to unlock after cold starts. Fan performance still seems better than stock, though the stock 5-blade on the 5.2 ZJ is different than what you have. Also my radiator is larger. Great work on your test videos!
I agree, I have never seen super accurate results with my anemometer either. I also started wondering if this was not an air flow issue as well. Which lead me to believe that maybe, at least for wranglers, the fan isn't most peoples issue to start with. My radiator is about 3 years old at this point. I elected to go with a Mopar replacement after trying a few other manufactures of radiators. However, in another video I did a flush and there was a good amount of junk that came out. I have flushed the radiator a few more times and junk keeps coming out. It seems the temperature is better, but without hot weather I am unable to run this test again. Once it warms up ill test it again and see what happens. I have two suspicions on how the junk got into my system in the first place. Thank you for your wealth of knowledge on the subject! Its conversations like these that really help us all.
@@EmbarkWithMark I've come back to your video and wanted to point out a few things... 1. The "Factory Mopar" fan clutch you have is just a rebranded Hayden 2791 fan clutch. The original factory fan clutch was made by Delco (not to be confused with ACDelco) or Delphi. Mopar is good at reselling aftermarket parts at a markup for older makes/models... They do this with thermostats too... which are rebranded MotoRad units. I do however stick with Mopar for oil filters. 2. You've sided with the stock configuration... and maybe it just works better on your Jeep... Though keep in mind that it was Jeep themselves who acknowledged the stock 5-blade was inadequate and released a TSB revised 7-blade metal fan for these Jeeps. They stopped making this 7-blade fan, so it's hard to find. This is what kick-started the search for alternate fan blades, such as the ones off the Explorer. 3. If you want to bring the Explorer fan closer to the radiator, there may be a fan clutch for Ford fan blades that has a longer shaft... May want to bring your Explorer fan to a parts store and ask them to bring out a fan clutch for an F150 and see if it fits (I know this one has the longer shaft). Or, you can buy a Hayden 2786 fan clutch. It's the severe duty long shaft fan clutch for GM fans... the Explorer fan and GM fans have the same hole in the center, however you'd need to drill out the holes on the Explorer fan for the bolts as the GM fan bolts are bigger. 4. If your shroud diameter is at least 20 inches, you may be able to fit the GM 11-blade fan on there. You'd use the 2786 fan clutch which has the long shaft like the 2791 you have. This fan is very common. They are on Chevy S10s, Blazers, Astro Vans, and Express Vans. Another option would be the 9-blade fan found on 99 and up Chevy Silverado/Tahoe/Suburbans with the 4.3/4.8/5.3/6.0 engines. Slightly smaller in diameter and uses the same 2786 fan clutch. I've been continuing this experiment with my Grand Cherokee 5.2L V8. The Explorer fan requires trimming the edges of the blades into a conical shape since the ZJ has a weird fan shroud. I've run this fan for probably 60k miles and it has worked well... but there is a different fan out there that came factory on some Jeep Liberty models with the tow package. It was also used on Jeep wrangler CRD models. I managed to find one and pull it for testing, and am currently running it. It bolts right up like it's OEM... Jeep in fact used this fan as a revised part for 1998 Grand Cherokee CA models with the 5.2L V8. It's an 11 blade fan and is nearly identical to the GM 11-blade people are talking about. The only difference is it has a conical shape to it (front diameter is smaller than rear/engine side diameter). I think this fan's performance may be in the middle between the stock 5-blade and the Explorer fan. The Liberty fan will bolt right up to any of the fan clutches you are running on the stock 5-blade fan. The OE replacement (heavy-duty) fan clutch for your Jeep would be the 2771. You have the severe duty 2791. This means the clutch may have a stronger lockup when the engine is hot. I find very little difference between the two... in fact, I run the 2771 since it unlocks much quicker on cold starts. Since I now have a fan blade that fits the OE style clutch (the Liberty fan), I can confirm that the stock 5-blade doesn't provide as much cooling as the Liberty fan and Explorer fan and that's due to the amount of drag it puts on the clutch... I'm finding the Liberty fan unlocks faster than the 5-blade. The difference at idle in-gear may be minimal, but once the RPMs go up, there's a bigger difference. I am also currently running a different fan clutch from GMB, made in Korea. It works well with the 11-blade Liberty fan, but I had noise issues with the stock 5-blade as it required surging the RPMs to 4000 to unlock on the freeway (when it was not even hot outside). The 5-blade on mine just does not pull as much air, and therefore less drag. The Hayden fan clutches seem to have 2 modes... fully disengaged, or fully engaged... Maybe not all of them... but I'm finding the GMB fan clutch will gradually have less slip as radiator heat begins to rise, and will lock fully when hot. As a result, when driving at slower speeds, I hear less fan noise, yet the coolant temp stays lower. Now if I sit in a drive-thru, my temps will climb like yours when it's 90 degrees or hotter with the A/C on. But it could be due to gunk in the radiator, as people in Arizona heat are reporting improved cooling performance with this fan on the 5.2 ZJ. Another big difference between the Liberty fan and the stock fan is noise... this fan can be locked up, yet I can still have a conversation in the Jeep. With the 5-blade, I'd have to shout. There's a seller on Amazon selling the GMB fan clutches much cheaper under a generic name "CsC". Just search "CsC cooling fan clutch assembly" on Amazon and you'll see them. I paid $35 for my 2771 fan clutch. They also sell fan clutches for the Explorer fan and GM fans.
You can keep the plastic clutch fan blade and add a water pump hub extension. Usually called a series 80 hub Assembly in some vehicles.
This way you get a more aggressive fan blade angle, more CFM's, a much lighter fan blade.
The closer your fam is to the radiator and futher in your fan shroud, the more air it will pull through the radiator and potentially AC condenser/PS cooler.
The lighter the fan blade the faster it can turn with the water pump and the less static resistance on the drive belt.
There is a parasitic draw on the engine from adding A heavy fan blade.
My WJ Mopar blade is 16 Lbs and the Dorman 620-155 plastic 11 fan blade i use is 3.3 Lbs and pulls 2x as much air and 1/3 the resistance on the engine so there is much less HP loss and loss of MPG.
The Mopar 7 metal blade added a 10HP loss.
The Dorman Plastic 11 blade only had a 2HP loss. 1/4.8 of the OE fan blade!
I just stumbled across this after reading up on the Ford swap. Thanks for saving me time and money!
Glad I could help!
I watched another video where the fella said he was able to just bolt the Jeep clutch to the ford fan and it worked good.
So yes, the ford fan does bolt right up to the Jeep fan clutch. From my understanding it does work well, but it also wears the Jeep fan clutch out a lot faster. Which, I could see since the Jeep fan clutch isn't designed to carry the load of the ford fan clutch.
I not positive on all of that, but it makes sense in my mind some how. Long story short, if Jeeps are getting hot, the cooling system needs to be looked into. They should run just fine on factory cooling components.
@@EmbarkWithMark Yes I think so as well.
My 03" 4.0 TJ has never been able to hold the AC in hot temps. A electric fan does real well but makes you overheat doing hyway speeds. The only real mod that can help maybe a little is the 93' fan according to others who have modded. But they are not clear on whether they are cooling in mild heat or full on 100F temps with the AC.
I have wheeled in over 110F temps with full AC and can get cold air if I give the stock fan 2000 rpm while sitting. But 110+ temps are probably not a smart off roading situation. I'm told "hell no. I'll wait till the temps are milder". Anymore I join in with the AC at home crowd at 100F outside.🤣
Definitely keeping my eye on this experiment. My LJ stays at 200-210 most of the time unless I’m driving up the 395 in the middle of summer. I have Metalcloak fenders with the louvers behind the front wheels which I think really helps keep the temps down. My next step will be to remove the hood insulation and maybe do a louver kit for the hood. I think the stock cooling system is up to the job for the most part so I don’t see changing out anything there.
Interesting. I know of a few close friends who have done hood louvers. It helped with engine bay temp but they claim it did not affect there engine temps. Honestly this confuses me a little.
As long as all the components are factory mopar parts and in good health you should be fine.
I’m going to continue diagnosing the system. I’m determined to figure out the cause. Hopefully by working on each section at a time I can save someone else time, frustration, and money. Thank you for your information!
Embark With Mark Yeah, that’s my mindset when it comes to parts as well. I like using the factory components when I can. Thankfully I’ve had little trouble with my LJ so I haven’t had to do much.
I do think that anything that can be done to remove heat from the engine bay is a good thing. Whether that’s louvers, vented fenders, or something else getting that
heat out is a good thing. When I installed the Metalcloak fenders I noticed my temp dropped about 10 degrees on the road. On the trail you can stick your hand near the louver and feel the heat coming out.
A few weeks back I had my first heat soak issue. We were climbing up Sherman Pass road out of Kernville and it was over 100 in the river valley. After we stopped at the trailhead to air down and I started the rig back up it was spitting and sputtering for about 20 seconds. It cleaned up after that and I had no other issues on the trip. Jeeps are never boring that’s for sure!
I changed my stock Mopar water pump when water started leaking from the weep hole to a Flowkooler water pump that supposed to pump more effectively and cool the engine, added a new 18psi cap and a new 185 degree thermostat and it didn’t do squat.
Yea, that is what I am finding out. I already new a low degree thermostat would not do much as the Tjs are designed to run at 210. But It is interesting to hear that "better" water pumps are not doing anything to help the issue. I am going to make this a series and go through each cooling system component to find the issue. Hopefully others will be able to learn from it and save some frustration,time, and money in the process.
How about a CSF 2 row radiator and engine hood vents or trying the Ford fan with the Jeep fan clutch ????
The Interesting part is that I have access to a 100% stock 2004 rubicon. That Jeep can idle in 110+ heat with ac on and never go above 208. In fact it cycles between 201 and 208.
My point is, is that I feel as though those mods should not be a requirement. But I may look to that in the future.
To the point with the Jeep fan clutch running a ford fan. The clutch is not strong enough to handle the resistance and will fail. It’s been documented so I feel it isn’t worth while burning up a perfectly new mopar fan clutch.
I’m going to continue my search for what the cause of the temperature difference is. I’ll be sure to document my path. I hope it helps someone in the future! Lol.
I use a severe duty clutch from a dodge application. Bolts in. The new clutch cools the coolant much faster than the old one but still gets to hot I feel like. Wish we could modify them to come on at a lower temp.
You should measure at what temp the clutch engages.
Also I think your radiator isn’t cooling as efficiently as maybe it once did when new.
What temp does your thermostat open? Does a lower temp thermostat keep it cooler?
Let’s get into the tech bro!
You can modify the fan clutches to lock earlier. You take that metal coil on front and tighten it up a few turns.
The radiator is a thought, though it is only a year old. A lower thermostat will not work correctly because the engine is designed to run near 210 by installing a lower temp thermostat all i would be doing is making the computer run in a "warm up" stage longer. Thermostats do not effect the cooling efficient of the system as long as they work correctly.
With all that being said, I'm thinking maybe something is plugged. I can confirm that the system should need no modification I have access to a 2004 Rubicon that is 100% stock. The hottest it will run is 207 and that is with the AC and in 110+ heat. So, something else is going on here. I am going to keep digging in here till I figure the issue out.
Check out the playlist th-cam.com/play/PLjcr5-AqFV1G7jYXYGUt0HkkTyRoV5L_D.html to see what I have done thus far.
Tell me more about your Jeep and its issue with running hot.
@@EmbarkWithMarkdid you recently change coolant? Could be air in the system.
But also likely the radiator has a few channels blocked with sludge.
Do not do a chemical flush, you risk clogging up more.
Take radiator off and flush with pressurized distilled water. You can even use an attachment on cap to add air compressor pressure to the system to push clean water through it without causing calcium deposits.
Try the Mopar clutch with the Ford fan blade....☺☺
Mopar clutch isn’t strong enough to hold the ford fan. But that would be an interesting experiment. 🤣
I think the original metal fan blade is heavier than the Ford plastic one I don't think there's going to be any problem with the fan clutch handling it
thelibyandude It’s not the weight, it’s the resistance of the 11 fan blades the ford fan has.
You're talking about Dimensions I think it has the same radius as the metal .... try it I think it will work out for your benefit. ☺☺
Dimensionally it will bolt it. The ford fan is the same radius as the TJ fan. That’s why it can be used. However the TJ fan clutch internals can not support the extra load the ford fan will place on it. It will work. But the load will just wear out a perfectly functioning fan clutch.
Well, that settles that. I was actually looking at a Ranger severe duty clutch and fan. I think you suffer from the same as i do at idle. Just need more air flow at idle. Need a clutch that would engage and rotate the fan like 90% of pump speed. Im pondering trying modifying the steel jeep fan to fit the Ranger severe duty clutch. Got to be a solution. As for the water pump I had a Flowkooler pump on mine and it clearly caused the motor to get warm at speeds when ambient temperature was high. Put stock type water pump on and temps at speed are much better.
That would be a Interesting idea. I’m not sure it’s an air flow issue anymore. I’m thinking there is an issue somewhere else. But I’ll be going through each cooling part and analyzing it. Hopefully I come to a conclusion. I’ll be making a video for each part I do so that hopefully it helps people to save some money, time, and frustration.
I'm thinking the Ford fan with a spacer to compensate. What do you think of that idea?
I’m not sure that will work honestly. I think there is more to. An engineer I know explained that more blades at not always better. Sometimes more blades are less effective because each blade grabs less air. It could be the way the ford clutch locks up too.
What I can tell you is I gained about 2mpg by going back to the factory setup.
I just don’t think it’s worth the money. I’m exploring other options. Other videos are to come diving deep into this issue.
Do you think results will the the same for 2000 Jeep WJ?
If the 2000 WJ is a 4.0. Than I would suspect so!
@@EmbarkWithMark 4.7
From what I understand is the 4.7 had a second fan option that was an electric and mechanical fan coupled together. Now I’m not sure you could only run the stock mechanical fan, but I do know that a ford 5.0 fan and clutch works very well on the 4.7s.
Funny I am just now seeing these newer videos of yours - That's awesome you tried the experiment again with the Ford 11-blade fan. Few things I want to mention...
I've never seemed to get 100% accurate results with my anemometer. One day, I could measure it at full temperature and get 5.7 MPH, while the next day, I could get close to 7MPH. I think surrounding winds (even the slightest breeze) could affect those numbers, and maybe even barometric pressure.
As far as the fan clutches go, both of those units you have there are aftermarket Hayden severe duty units. You could mount the Ford fan to the clutch for your stock fan, and it would work... however I believe the size of the center hole and bolt holes, are different.
As for your Jeep getting hot even with the Explorer fan, I have to wonder if there's something going on with your Jeep's radiator. Has it been replaced? There could be some gunk in there plugging some of the passage ways. It's possible since your heater seems to bring it right back down.
I've seen a lot of people trying Explorer fans on various Jeeps that had a 5-blade fan stock... some get better results, others like you, didn't. I still run a modified 11-blade Explorer fan on my Grand Cherokee 5.2L V8. I had to replace the fan clutch with another one in 2019 because it started not wanting to unlock after cold starts. Fan performance still seems better than stock, though the stock 5-blade on the 5.2 ZJ is different than what you have. Also my radiator is larger.
Great work on your test videos!
I agree, I have never seen super accurate results with my anemometer either.
I also started wondering if this was not an air flow issue as well. Which lead me to believe that maybe, at least for wranglers, the fan isn't most peoples issue to start with. My radiator is about 3 years old at this point. I elected to go with a Mopar replacement after trying a few other manufactures of radiators.
However, in another video I did a flush and there was a good amount of junk that came out. I have flushed the radiator a few more times and junk keeps coming out.
It seems the temperature is better, but without hot weather I am unable to run this test again. Once it warms up ill test it again and see what happens. I have two suspicions on how the junk got into my system in the first place.
Thank you for your wealth of knowledge on the subject! Its conversations like these that really help us all.
@@EmbarkWithMark I've come back to your video and wanted to point out a few things...
1. The "Factory Mopar" fan clutch you have is just a rebranded Hayden 2791 fan clutch. The original factory fan clutch was made by Delco (not to be confused with ACDelco) or Delphi. Mopar is good at reselling aftermarket parts at a markup for older makes/models... They do this with thermostats too... which are rebranded MotoRad units. I do however stick with Mopar for oil filters.
2. You've sided with the stock configuration... and maybe it just works better on your Jeep... Though keep in mind that it was Jeep themselves who acknowledged the stock 5-blade was inadequate and released a TSB revised 7-blade metal fan for these Jeeps. They stopped making this 7-blade fan, so it's hard to find. This is what kick-started the search for alternate fan blades, such as the ones off the Explorer.
3. If you want to bring the Explorer fan closer to the radiator, there may be a fan clutch for Ford fan blades that has a longer shaft... May want to bring your Explorer fan to a parts store and ask them to bring out a fan clutch for an F150 and see if it fits (I know this one has the longer shaft). Or, you can buy a Hayden 2786 fan clutch. It's the severe duty long shaft fan clutch for GM fans... the Explorer fan and GM fans have the same hole in the center, however you'd need to drill out the holes on the Explorer fan for the bolts as the GM fan bolts are bigger.
4. If your shroud diameter is at least 20 inches, you may be able to fit the GM 11-blade fan on there. You'd use the 2786 fan clutch which has the long shaft like the 2791 you have. This fan is very common. They are on Chevy S10s, Blazers, Astro Vans, and Express Vans. Another option would be the 9-blade fan found on 99 and up Chevy Silverado/Tahoe/Suburbans with the 4.3/4.8/5.3/6.0 engines. Slightly smaller in diameter and uses the same 2786 fan clutch.
I've been continuing this experiment with my Grand Cherokee 5.2L V8. The Explorer fan requires trimming the edges of the blades into a conical shape since the ZJ has a weird fan shroud. I've run this fan for probably 60k miles and it has worked well... but there is a different fan out there that came factory on some Jeep Liberty models with the tow package. It was also used on Jeep wrangler CRD models. I managed to find one and pull it for testing, and am currently running it. It bolts right up like it's OEM... Jeep in fact used this fan as a revised part for 1998 Grand Cherokee CA models with the 5.2L V8. It's an 11 blade fan and is nearly identical to the GM 11-blade people are talking about. The only difference is it has a conical shape to it (front diameter is smaller than rear/engine side diameter). I think this fan's performance may be in the middle between the stock 5-blade and the Explorer fan. The Liberty fan will bolt right up to any of the fan clutches you are running on the stock 5-blade fan. The OE replacement (heavy-duty) fan clutch for your Jeep would be the 2771. You have the severe duty 2791. This means the clutch may have a stronger lockup when the engine is hot. I find very little difference between the two... in fact, I run the 2771 since it unlocks much quicker on cold starts. Since I now have a fan blade that fits the OE style clutch (the Liberty fan), I can confirm that the stock 5-blade doesn't provide as much cooling as the Liberty fan and Explorer fan and that's due to the amount of drag it puts on the clutch... I'm finding the Liberty fan unlocks faster than the 5-blade. The difference at idle in-gear may be minimal, but once the RPMs go up, there's a bigger difference.
I am also currently running a different fan clutch from GMB, made in Korea. It works well with the 11-blade Liberty fan, but I had noise issues with the stock 5-blade as it required surging the RPMs to 4000 to unlock on the freeway (when it was not even hot outside). The 5-blade on mine just does not pull as much air, and therefore less drag. The Hayden fan clutches seem to have 2 modes... fully disengaged, or fully engaged... Maybe not all of them... but I'm finding the GMB fan clutch will gradually have less slip as radiator heat begins to rise, and will lock fully when hot. As a result, when driving at slower speeds, I hear less fan noise, yet the coolant temp stays lower. Now if I sit in a drive-thru, my temps will climb like yours when it's 90 degrees or hotter with the A/C on. But it could be due to gunk in the radiator, as people in Arizona heat are reporting improved cooling performance with this fan on the 5.2 ZJ. Another big difference between the Liberty fan and the stock fan is noise... this fan can be locked up, yet I can still have a conversation in the Jeep. With the 5-blade, I'd have to shout.
There's a seller on Amazon selling the GMB fan clutches much cheaper under a generic name "CsC". Just search "CsC cooling fan clutch assembly" on Amazon and you'll see them. I paid $35 for my 2771 fan clutch. They also sell fan clutches for the Explorer fan and GM fans.
Sell it buy the new Bronco problem solved.
🤣. I’d rather keep my trusty TJ.
@@EmbarkWithMark A good man never buys the first revision. Especially a vehicle.