YJ Radiator Upgrade

Cribbetr · 01-04-2015, 11:10 AM

I'm looking to upgrade the radiator in my my 91 YJ. The radiator that's in there now is original and is showing it's age. I'm going to replace with aluminum an electric fan set -up.

My questions is who makes a good quality radiator/e-fan kit for my YJ.

blazerbrad · 01-04-2015, 01:43 PM

Are you having cooling issues now? To be honest I'm not a big fan of either aluminum radiators or electric cooling fans. All other things being equal they do not offer better cooling ability.

Engine driven fans generally provide more air flow and are more reliable. I've seen lots of people lose electric cooling fans on the trail for various reasons. You can turn a e-fan off for deep water crossings but I have never personally seen a situation where it would really help. Using them for auxiliary/secondary fans is okay.

Same thing goes for aluminum radiators. If the sizes are equivalent an aluminum version actually has less cooling ability. I think the perception from a lot of people is they think spending 2 to 5 times more on a part makes it better. Also they replace the half clogged and leaking old radiator with a bling aluminum and now the engine stays cool they think it is because the new radiator is great, not because the old one was junk.

Maybe an aluminum radiator holds up better when being bounced around hard off-road, but I have never seen a radiator fail because of this.

comanchedude · 01-04-2015, 04:28 PM

Opinions will vary of this subject. if you just need a rad, most any after market replacement unit will do the job. ( I prefer copper units) and if your factory fan system is working correctly its less expensive to just replace the rad. if you choose to go electric (I run Electric) it has a double cost setup. also make sure you have a alternator to support the electric fan a good fan (or fans) will require 20 to 40 amps so 90 amp alternator and above is recommended
but if you just replace the rad ,it will be much cheaper and will do just fine for stock setup.. as for brands I really don't think its matters that much.

93 Krawler · 01-05-2015, 01:45 PM

I used an aluminum radiator for a v8 conversion on the 88 YJ at work. It has a 4.3 GM V6 in it. I used an electric fan because the stock fan didn't work out well. It has a 3" body lift. I have gone through 3 different fan controllers over the past ten years. I constantly keep an eye on the temp, just waiting on the controller to fail again. Eliminating the mechanical fan will bite you in the ass eventually. I only drive the Jeep when I have to plow snow. I would imagine a DD would make the controller die faster. A computer controlled fan would be totally different. A stock radiator and fan should do you fine. Add a manual electric fan if you need extra cooling if you're off-road. That's how my rig is set up.

WrenchMonkey · 01-05-2015, 07:53 PM

The aux XJ fan just uses a probe in the radiator and a relay. Pretty reliable.

I just replaced my mech primary with an electric. I used an ignition-hot line to trip another relay, so it's always on.

It's working fine in January, we'll see in July...

Ky Mudhunter · 01-06-2015, 01:19 PM

I recommend using a Ford Taurus 3.8L dual speed fan and the fan control relay from a Volvo. This is what I am running in my S10 with the LT1 PCM controlling them. Below is a link to a good write up showing how to wire the relay. It also mentions an option using a BMW temp switch to control the fans.

http://www.syty.net/forums/showthread.php?t=99248

nshefbuch · 01-06-2015, 01:25 PM

While copper does transfer thermal heat better than aluminum the reason for the switch to aluminum is radiators actual cooling process happens from the core design rather than what material it is made of. Aluminum was chosen to save weight mainly and the design of all aluminum cores will out perform any copper core. You take the same exact size radiator of each and the aluminum will out perform the copper because of the core design and how it's bonded together.

In my CJ I'm using a Novak aluminum radiator and is well worth the money because of their warranty. I had a small leak develop and called them and they sent me a replacement one right away and said to use the same box and send the old one back. No questions asked all they wanted was a few pictures of the leak. Great service but was expensive.

01-04-2015, 11:10 AM	#1
Cribbetr Join Date: Jan 2010 Location: Cincinnati Posts: 14	YJ Radiator Upgrade I'm looking to upgrade the radiator in my my 91 YJ. The radiator that's in there now is original and is showing it's age. I'm going to replace with aluminum an electric fan set -up. My questions is who makes a good quality radiator/e-fan kit for my YJ.

01-04-2015, 04:28 PM	#3
comanchedude COMANCHE NUT Join Date: Jan 2007 Location: Ross Twp Posts: 166	Opinions will vary of this subject. if you just need a rad, most any after market replacement unit will do the job. ( I prefer copper units) and if your factory fan system is working correctly its less expensive to just replace the rad. if you choose to go electric (I run Electric) it has a double cost setup. also make sure you have a alternator to support the electric fan a good fan (or fans) will require 20 to 40 amps so 90 amp alternator and above is recommended but if you just replace the rad ,it will be much cheaper and will do just fine for stock setup.. as for brands I really don't think its matters that much. __________________ just don’t get stupid and stick a Chevy engine in your Jeep. Man I hate that

01-05-2015, 07:53 PM	#5
WrenchMonkey Mechanical Animal - CORE Member - - Moderator - Join Date: Feb 2008 Location: Beechmont Posts: 1,883	The aux XJ fan just uses a probe in the radiator and a relay. Pretty reliable. I just replaced my mech primary with an electric. I used an ignition-hot line to trip another relay, so it's always on. It's working fine in January, we'll see in July... __________________ DIRTY DEEDS, DONE DIRT CHEAP Whatever doesn't kill you makes you stranger

01-04-2015, 01:43 PM	#2
blazerbrad - CORE Member - Join Date: Feb 2007 Posts: 831 Images: 6	Are you having cooling issues now? To be honest I'm not a big fan of either aluminum radiators or electric cooling fans. All other things being equal they do not offer better cooling ability. Engine driven fans generally provide more air flow and are more reliable. I've seen lots of people lose electric cooling fans on the trail for various reasons. You can turn a e-fan off for deep water crossings but I have never personally seen a situation where it would really help. Using them for auxiliary/secondary fans is okay. Same thing goes for aluminum radiators. If the sizes are equivalent an aluminum version actually has less cooling ability. I think the perception from a lot of people is they think spending 2 to 5 times more on a part makes it better. Also they replace the half clogged and leaking old radiator with a bling aluminum and now the engine stays cool they think it is because the new radiator is great, not because the old one was junk. Maybe an aluminum radiator holds up better when being bounced around hard off-road, but I have never seen a radiator fail because of this.

01-05-2015, 01:45 PM	#4
93 Krawler >>>PMC<<< - CORE Member - - Administrator - Join Date: Sep 2010 Location: Ross, OH Posts: 2,069 Images: 1268	I used an aluminum radiator for a v8 conversion on the 88 YJ at work. It has a 4.3 GM V6 in it. I used an electric fan because the stock fan didn't work out well. It has a 3" body lift. I have gone through 3 different fan controllers over the past ten years. I constantly keep an eye on the temp, just waiting on the controller to fail again. Eliminating the mechanical fan will bite you in the ass eventually. I only drive the Jeep when I have to plow snow. I would imagine a DD would make the controller die faster. A computer controlled fan would be totally different. A stock radiator and fan should do you fine. Add a manual electric fan if you need extra cooling if you're off-road. That's how my rig is set up.

01-06-2015, 01:19 PM	#6
Ky Mudhunter Join Date: May 2013 Posts: 75	I recommend using a Ford Taurus 3.8L dual speed fan and the fan control relay from a Volvo. This is what I am running in my S10 with the LT1 PCM controlling them. Below is a link to a good write up showing how to wire the relay. It also mentions an option using a BMW temp switch to control the fans. http://www.syty.net/forums/showthread.php?t=99248

01-06-2015, 01:25 PM	#7
nshefbuch Join Date: Jul 2008 Location: piqua, ohio Posts: 76	While copper does transfer thermal heat better than aluminum the reason for the switch to aluminum is radiators actual cooling process happens from the core design rather than what material it is made of. Aluminum was chosen to save weight mainly and the design of all aluminum cores will out perform any copper core. You take the same exact size radiator of each and the aluminum will out perform the copper because of the core design and how it's bonded together. In my CJ I'm using a Novak aluminum radiator and is well worth the money because of their warranty. I had a small leak develop and called them and they sent me a replacement one right away and said to use the same box and send the old one back. No questions asked all they wanted was a few pictures of the leak. Great service but was expensive.