Daubies at home HEMI conversion

AjordanH said:
I’ll share my current experience and maybe @Wildman and @NashvilleTJ will chime in soon.
My situation is somewhat unusual. I drive my LJ a lot. It’s almost a daily driver for me but I also use it to tow a 3200# travel trailer and then unhook from it and trail ride and sightsee or adventure wherever we go. So it’s a Swiss Army knife type rig.
When I did my Hemi swap I used a stock replacement water pump, thermostat and a custom CG&J radiator with a flex-a-lite black magic electric fan for TJs. I used the same hoses as @Daubie3. I do have Air conditioning and a transmission cooler and power steering cooler in my grill with a warn 9.5 ctis winch in front of everything. My radiator is a down flow style with a built in oil cooler. The CG&J radiator is a really nice and well made piece. BUT immediately I had overheating issues. You’ll read about them in this thread. With the Efan i would overheat at highway speeds. Pretty much anything above 45-50 and it would hit 245-250 degrees within 10 miles. So I reluctantly swapped the Efan for the stock jeep 4.0 fan and shroud with some modifications to the shroud to fit the Hemi inlet and outlet on the radiator. I did not overheat at 55mph but it would overheat at idle and if towing. So I swapped to the explorer fan and severe duty clutch. I hated it. It was very loud and you could just feel it suck the power out of the engine. Now I could tow at 60-65 before overheating but it still overheated at idle, in traffic, and when moving slow offroad. I tried a standard clutch in place of the severe duty with little change in the noise. The I found a similar fan design that was on a Jeep WJ I think. I tried the Dorman replacement for it (620-082) and matching standard duty clutch. It is significantly quieter and less drag on the engine. But still overheated under the same circumstances. Then I tried the severe duty clutch for it (Hayden 2791). And only slightly more noise but still overheated. I found a Flowcooler water pump for the truck Hemi. That’s where I’m currently at.
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Great info, thank you! How is the current setup working?
 
My recent experience with the flowcooler may have revealed my biggest problem. Only a couple days after installing the flowcooler water pump I hooked to the camper for a 400 mile trip to the beach. The first 30 miles my temps were in the 198-205 range. Hemi pulled good and I was really pleased. Then I started getting water on my windshield. My overflow bottle was overflowing like it was hot but my temps were normal at that time. I forgot to mention somewhere along the way I swapped to a 180 degree thermostat and even added louvers to my hood to try to help. Coolant was coming out my louvers 😩. I have tried multiple radiator caps because anytime my jeep overheated I had coolant coming out the overflow tank. I currently have an 18# cap. I think the flowcooler water pump is pushing coolant out of my radiator since the cap is on the high pressure side of the system with the downflow radiator design. Still overheated at idle or in traffic btw. So I have currently ordered a new radiator from ECP that is a cross flow design like Wildman and NashvilleTJ run. I don’t know how I can mount my stock tj shroud to this style radiator so I may try the Efan with it. I’ll probably try to get the Spal 850 Camaro fan and PWM controller like Wildman in the near future. I’ll update here again with the results. Let me know if you have questions I might could answer. Let us know your experience with it.
 
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AjordanH said:
I’ll share my current experience and maybe @Wildman and @NashvilleTJ will chime in soon.
My situation is somewhat unusual. I drive my LJ a lot. It’s almost a daily driver for me but I also use it to tow a 3200# travel trailer and then unhook from it and trail ride and sightsee or adventure wherever we go. So it’s a Swiss Army knife type rig.
When I did my Hemi swap I used a stock replacement water pump, thermostat and a custom CG&J radiator with a flex-a-lite black magic electric fan for TJs. I used the same hoses as @Daubie3. I do have Air conditioning and a transmission cooler and power steering cooler in my grill with a warn 9.5 ctis winch in front of everything. My radiator is a down flow style with a built in oil cooler. The CG&J radiator is a really nice and well made piece. BUT immediately I had overheating issues. You’ll read about them in this thread. With the Efan i would overheat at highway speeds. Pretty much anything above 45-50 and it would hit 245-250 degrees within 10 miles. So I reluctantly swapped the Efan for the stock jeep 4.0 fan and shroud with some modifications to the shroud to fit the Hemi inlet and outlet on the radiator. I did not overheat at 55mph but it would overheat at idle and if towing. So I swapped to the explorer fan and severe duty clutch. I hated it. It was very loud and you could just feel it suck the power out of the engine. Now I could tow at 60-65 before overheating but it still overheated at idle, in traffic, and when moving slow offroad. I tried a standard clutch in place of the severe duty with little change in the noise. The I found a similar fan design that was on a Jeep WJ I think. I tried the Dorman replacement for it (620-082) and matching standard duty clutch. It is significantly quieter and less drag on the engine. But still overheated under the same circumstances. Then I tried the severe duty clutch for it (Hayden 2791). And only slightly more noise but still overheated. I found a Flowcooler water pump for the truck Hemi. That’s where I’m currently at.
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While I don't DD mine I'm also not easy on it and IMO have stressed it fairly hard. I've currently have a stock water pump on my engine but I do have a Flowcooler water pump sitting in my garage. I've got a list of things I'm going to do to mine which is the Flowcooler & Camero electric fan....
Now with all that said I wasn't having overheating issues with my SPAL 300 watt fan originally. I think I've got a sticking thermostat but plan on just updating the cooling system to CMA...

I do think a mechanical fan can work and in some situations may be better than an electric but with the current iteration of brushless electric fans I think they can now hold their own against a mechanical fan. And there are times a electric fan has a plus.... Like in water crossings.
 
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Agar426 said:
Thank you! This is the rabbit hole I'm going down now. I know I want 35s, but the way they did it back when AEV was building them was to use the longer coils, which over the years was determined to cause other issues, hence the now "standard" 4" suspension + 1.25" body, with 1" motor mount lift. I'm not a fan of body lifts, but willing to do it to get the "proper" level of performance (that's a can of worms, I know). But, there don't seem to be any COTS MM lifts for the hemi swap, etc, etc, etc. Can open, worms everywhere......at least from my untrained hands. I own an AEV TJ already, but it has the 4.0, this unlimited is my friend's Jeep, we ordered them from AEV at the same time. I'm basically getting the Jeep I wish I could have bought to begin with.
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OK first off instead of clogging up the OP's thread MORE I'd suggest you start your own thread in the General Discussion area.... Then we can answer all your questions.
 
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