Ultimate cooling

With out worry about cost what would be the most effective way of keeping our 4.0s or 4.7s cool? What is the optimum radiator that fits stock? Or is there a way to modify the front end to exept a taller radiator? What and where to mount a oil cooler and trans cooler? Any other tricks to the moter i.e. fins on oil pan, fins on lines, cold air intake.?

Lets have it.

Start with a good fan clutch.

http://www.naxja.org/forum/showthread.php?t=63102

CRASH said:

Start with a good fan clutch.

http://www.naxja.org/forum/showthread.php?t=63102

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Agreed, I replaced my fan clutch and I haven't had temp problems again.

So that is the secret? All the other wizbzng ideas are a waste?
What is the GM part number for the fan clutch that works? I now on my jeep V8 I used to use a GM 1 ton fan clutch, but not sure if it will fit the 4.0
What about going electric? what size and brand?

XJJack said:

So that is the secret? All the other wizbzng ideas are a waste?
What is the GM part number for the fan clutch that works? I now on my jeep V8 I used to use a GM 1 ton fan clutch, but not sure if it will fit the 4.0
What about going electric? what size and brand?

Click to expand...

I have two possibilities on order. I'll report back when I get and install them. It may come down to index hub diameter, as bolt pattern and depth is the same.

New Modine 2-core, OEM lower radiator hose (with spring!!!), 97+ aux. electric fan, unmolested OEM fan shroud, good, lockup fan clutch.

An oil cooler may help, but I have no direct experience with them.

This will solve all but the most extreme cooling situations.

I have seen desert racer xjs with oil and tranny coolers mounted on ceiling in rear of cabin with louveres cut into roof to allow air flow, these seemed to work very well, even when it is 110F outside and climbing silt-covered slopes at full throttle, not good for an everyday driver for obvious reasons.

I agree with the working fan clutch comment. I have an entirely stock cooling system on my 4.6, and I just touch 210 in mixed driving on 100 degree days, with the AC blasting...

A friend of mine welded his clutch so that it stays locked up. No cooling problems anymore. It's probably hell on his water pump though.

Didn't know about the spring in the lower rad hose. I just changed mine. I saw the spring, but the replacement didn't have one. I assumed it didn't need one.

Have a custom copper radiator made.

HotChiliRam said:

Agreed, I replaced my fan clutch and I haven't had temp problems again.

Click to expand...

Replaced it with what? OEM? or AM

Fit a hesco high flow water pump and robert shaw or mr gasket thermostat too if you want the best. See my site for more details. www.go.jeep-xj.info
Remember those who are locking their clutches, it WILL cost you performance and mileage which is why they were invented in the first place to reduce these!

Does a oil cooler actually do that much? I assume it would, but I dont know.

Has anyone put one on a 4.0/4.6 etc and have any feedback? I have looked into them, but havnt really found that much.

Does the Robert Shaw/Mr. Gasket Thermostat have a weep hole like the OEM t-stat?

No but I have never had a bleed problem either but the old cooling systems might pre 91 might?

factory thermostat, NAPA fan clutch & water pump, Prestone rad. cleaner, the kind you drive around with for like a week, Prestone backflush kit.

(GDI rad.)

Worked wonders in my '98 w/105k

have a local rad shop pressure test, then see if worth boiling out, may save cost of a new rad.

sv

Cost be damned, Novak (the adapter people) have a direct replacement aluminum radiator that is made to cool a seriously large engine in a XJ.
I don't have one, but have talked to them about it, and will be part of my stroker build.
I do have a couple of similarly set up XJ's and my three row CSF radiator out performs my three core GDIs.
My real problem isn't the heat dissipation potential of the radiator, but air flow at crawl. At this, the only real air flow is from the stock electric fan (all updated to 97+ units)
I've bit the bullet and sprang for an OEM fan clutch only to find it worked no better than the $40 Autozone one it replaced, or my other 15+ year old originals, no real howl of wind when you need it.
As I'm not real worried about a little loss of power compared to the heat I'm barely dissipating, crawling, with the 100+ temps, and 1000ft per mile climbs on my local trails, I'm trying a 15" (stock shroud size) RV fan on a solid spacer. The stock fan has a very aggressive blade pitch (hence the noise when they try to work) yet the fan clutch never really locks up, so I'm hoping for a better compromise. Remember this is all reverse rotation stuff, the RV fan is good to 10,000rpm (don't know about the stock one) and it's not the water pump, but a dummy jackshaft it rides on, so I'm not worried about aditional loads, as long as I don't burn the back of the belt with hard starts and stops.
I'll post back how it works in a couple of runs, I'm whittling the spacer right now on the lathe, don't like the die-cast pot metal ones they sell.