I might be doing something dumb to an 02 kj....

[H0rizonfire]

So here is the deal. I am pretty mechanically inclined. But i am also pretty inclined to getting in way over my head on projects. My ask here is for the people that know to talk me out of (or into) what i am doing here.

Short of the long is this. The ac system in my liberty has been borked for years before i bought it, and i don't care if it has ac or not. I also have a (apparently common) crack at the top of the rad. So I need a new rad. OEM seems impossible to find and putting an aftermarket plastic tank rad in just seems like asking to do the same job over and over. I am planning to do a full ac system removal and find an aluminum rad i can make mounts for and stuff into this here jeep.

The plan is this, find or design / make (I'm pretty handy with CAD) some block off plates to block the ac lines going through the firewall. Hopefully i can find an off the shelf plug. Something like this:

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Once that is done, I now have a super convenient location to mount a catch can (the mount location for the ac accumulator). This would also allow me to remove the entire ac system. including the condenser.

From there (I think) I now have more space to mount an aluminum rad. The plan would be to find a rad that fits, My understanding is the existing rad is 20 x19 x 1 inch ish, then find 2 fans that will fit what ever rad i find. I also plan to remove the clutch fan and shroud and install a new water pump while i am in there. If i can find 2 suitable electric fans, i can design and have laser cut an aluminum fan shroud. The fan on the passenger side would use the existing wiring harness for the AUX fan that should kick in if temps start to increase, and then the drivers side fan would be wired into a fuse in the fuse box, a relay, and taped into an existing line that has 12v when the ignition is on. I am removing the cruise control module as it has a fun(deadly) issue, so depending on how that is wired up i may be able to use that for the main fan relay. Haynes manual is on the way, so hopefully that will have enough info in it to resolve some of my question.

On a cooler note, anything i design (if it works) will be documented and i will post the files up on GitHub so anyone else that needs them can have them.

So... oh great KJ builders. Has this been done before? Is there info that i am too bad at searching to find? Is this a terrible idea? Does anyone have any suggestions for parts or mental hospitals?

 

[blackhawk]

I have seen in ebay a couple of years ago aluminum rad for our kj.

 

[KJowner]

Sounds like a large project, I can't say I've had enough problems with replacement radiators to bother pulling everything and replacing it with a custom one.
If you look on here there is a link to download the factory manuals for free.

 

[mrlavalamp]

The aftermarket radiators aren't terrible, but they are not all created equal.

This unit lasted me 6 years, and at the time i purchased I remember it saying it was an "improved design" (https://www.rockauto.com/en/moreinfo.php?pk=499658&cc=1432214&pt=2172&jsn=9).
It did not crack/leak on the upper drivers side like most do so I am pretty happy with it considering cost/life. Mine developed a pinhole in the middle of the element this fall. Not a bad run for a $100 rad.

I have been eyeing the all aluminum rads for a while now so I decided to go for it with this 4-row unit: https://www.ebay.com/itm/404661387753

The radiator fit the stock mounting points perfectly, construction/welds all appear to be good.

The only issue so far: the 4-row model is very deep, much deeper than OEM rad designs. It holds ~1/2 gallon more coolant because of this extra depth/volume. Unfortunately the added thickness pushes the fans toward the engine enough that the HD cooling system will no longer fit. I removed the mech. fan and clutch and kept the HD electric fan/shroud, so far so good but I believe the HD electric fan moves less CFM than the standard electric fan, so I am planning to swap that soon.

I am hesitant to recommend this "upgrade" until I have had the summer heat to test/vet it, but that wont be until may or so when we get back into the 90's and 100's.

I see now that ebay is chock full of all alu rads WITH a 3000 cfm fan included. Not sure how that stacks up to the factory fans as the cfm ratings are nigh impossible to find, but they claim to pull 10 amps vs 12amps on HD cooling and 16 amps on standard cooling. All else being equal (blade shape, rpm etc.) more amps should mean more cfm, its just hard to find enough specs on any one fan to tell.

 

[mrlavalamp]

update to let yall know i got some confirmation from Dorman on their rad fan CFM's

According to Dorman tech support:
Dorman Part#621-018 (HD COOLING ELECTRIC FAN) moves 32.23 CMM which is 1,138 CFM

Dorman Part#620-053 (NON-HD ELECTRIC FAN) moves 76 CMM which is 2,684 CFM.

This makes sense to me as the HD setup also has a mech fan that moves a lot of air when the clutch locks up.

I don't totally trust the ebay sellers when it comes to the fan specs, their fan cannot be BOTH 3,000 cfm AND 10 amps, one is "fluffed" and it is probably the CFM #.

Really though, if you want to go total custom and make a shroud that lets you mount 2 fans, then go for it, etrailer is a great source for the "universal" fans as they have tons to choose from and they include a lot of the info you would need like accurate dimensions and specs. Cursory glance tells me it is going to be a TON of work (especially making your own 2 stage), and frankly I dont think you will be able to beat the 2600 cfm on the stock base model fan.

 

[Duster]

The AC is easy to fix and not insane expensive if you buy the parts online.

If you don't know what is wrong with it, get a kit with the compressor, the line that has the filter in it, and the accumulator canister... that way if the compressor burned out you don't feed the new one metal shavings, etc.