What are you doing to your rig - the continuing saga

I also have a 2 row all metal and it doesn't even do as well as the single wide core that's in it now. I just find it ironic that the 80 dollar rad would cool better than the 200 dollar rads.
 
If I can figure out how to fit the durango radiator in I can use a mechanical clutch fan too. I can fit a WJ mechanical now without the electrics but half the fan is below the radiator doing nothing. It sure pulls some air when it locks tho. Maybe a shroud designed to fit around the xj rad / wj mech fan would work. Alot of work and materials wasted if it doesn't tho.
 
All metal doesn't matter. What matters is the size of the tubes vs the ability of the pump to move fluid. If the two row doesn't work as well as the one row, what is the comparitive cross sections of the tubes? If the two row is twice the one row, it's a pumping problem or an airflow problem, or you have air in the system so the pump can't perform at it's best.
 
Forget about changing parts, decide the problem and go from there. You're flailing with all this part substitution stuff.
 
What I don't have is enough airflow through the xj sized radiator to cool 360 cid. I'm currently using the dirtbound 3 fan kit and it is just not able to pull enough air to cool the water passing through the radiator at 2000 rpm. I tried using 2 OEM electrics and while a touch better, still not enough.

So, one solution is achieving more surface area, i.e. the durango radiator which is the same thickness but twice as tall as the XJ rad and using a shroud and mechanical fan with possibly a pusher fan or two in front for low speeds and rock crawling.

Another solution is to add more volume and cooling capacity by adding a remote heat exchanger.
 
Digger87xj said:
What I don't have is enough airflow through the xj sized radiator to cool 360 cid. I'm currently using the dirtbound 3 fan kit and it is just not able to pull enough air to cool the water passing through the radiator at 2000 rpm. I tried using 2 OEM electrics and while a touch better, still not enough.

So, one solution is achieving more surface area, i.e. the durango radiator which is the same thickness but twice as tall as the XJ rad and using a shroud and mechanical fan with possibly a pusher fan or two in front for low speeds and rock crawling.

Another solution is to add more volume and cooling capacity by adding a remote heat exchanger.
Click to expand...

Coming from Florida, I battled over-heating issues on nearly every vehicle I owned - I feel your pain. I would highly recommend doing what Fred said and add some vents or a cowl to your hood. Due to the convection process, all of those fans will just push/trap the heat under the hood if it has no place to exhaust from.

I have an extra hood with a vent on it if you'd like to try that before you spend a bunch of time and money throwing parts at a new radiator/fans.

Let me know,
Jim
 
I have a hood scoop, and the hood is raised 3/4 of an inch at the rear. I stated that in an earlier post. It has made no difference either way. The whole reason for the V8 is that I couldn't keep the 4.0 cool because it was overworked,
I now find myself with the same problem but with a different cause.
Today I removed the scoop (a subaru WRX scoop) and have a massive hole in the hood.

I do not believe that air is backing up under the hood.

I've confirmed that 3 10 inch fans are not enough to cool a 5.9 V8. Especially on an XJ radiator of any number row or composition.

I need 3 super-dee-duper 10" turbo fans of some sort or a larger single fan/shroud setup to draw enough air across the XJ radiator. I don't think any form of aftermarket electric fan will do the job I need. I've tried fitting the taurus fan and just don't have room for it between the nose of the water pump and the radiator.

A radiator where the full circumference of the WJ mechanical fan is effective will be ideal. It is doable but is it plausible? Not without a ton of re-engineering of the front clip.
 
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Are you sure you don't have a lean condition? Because it seems very strange that you're seeing increasing temperatures at high speeds. That's not usually common with a radiator deficiency.

You didn't happen to check the water passages in the heads when you did the swap, did you?

I would think that with 3-10 fans you would keep it within the 210* +-10* range at any MPH, regardless of the radiator. Just seems like a lot of air without a lot of benefit. I'm suspecting it's something else other than the airflow.
 
The heads are "new" remans. The short block was disassembled and the block was sonic cleaned, new cam bearings, a fresh hone and new rings and bearings. New timing chain and gears and new oil pump.

Fuel pressure is rock steady during all driving conditions fluctuating between 47 and 50 PSI depending on demands. Spec is 44 -54 measured at idle. Measured volume is more than adequate.

Had the scan tool on it for the last 2 days and it is running numerically perfect. fuel trims are neutral, O2 pegs at .9v at WOT and I'm getting a nice 14.5 mpg.

Absolutely no power problems.. this thing runs awesome. Plenty of power to spare at cruising speed. It will honk up I70 to genesee at 75 mph without troubles. Just not without creeping up and getting hot when the ambient temp is over 65 degrees.

The cooling system was vacuum-filled which virtually eliminates the chances of air pockets.
 
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Digger87xj said:
The heads are "new" remans. The short block was disassembled and the block was sonic cleaned, new cam bearings, a fresh hone and new rings and bearings. New timing chain and gears and new oil pump.

Fuel pressure is rock steady during all driving conditions fluctuating between 47 and 50 PSI depending on demands. Spec is 44 -54 measured at idle. Measured volume is more than adequate.

Had the scan tool on it for the last 2 days and it is running numerically perfect. fuel trims are neutral, O2 pegs at .9v at WOT and I'm getting a nice 14.5 mpg.

Absolutely no power problems.. this thing runs awesome. Plenty of power to spare at cruising speed. It will honk up I70 to genesee at 75 mph without troubles. Just not without creeping up and getting hot when the ambient temp is over 65 degrees.
Click to expand...

Hmmmmmmm......

What about your radiator cap? Are you at the 14lbs rating that the 5.9 calls for? 195* thermostat?

Are you using the premix coolant or the 50/50 with distilled water?

This is going to bug me now.
 
I would try to get a lower lbs rated cap and see if the reduced pressure helps. 21lbs seems really high. A little less than double what the Magnum originally came with.

To me, this would make sense. As your pump is spinning faster, the coolant is being pushed through a pressurized system at a higher rate of speed; which causes a lot more heat if the pressure isn't adequately released, reducing it's boiling point.

IDK brother...you might be right, and it may just be the radiator. But I'd bet changing the cap would really help.
 
I disagree about the cap.
too low pressure cap and it will blow off, raising temps. Too high and you start popping gaskets. Not really worried about popping gaskets, I'm not letting it get that hot.

Today was the first day for the 21 psi cap anyhoo. I had the cap on that came with the champion radiator, which was not labeled but I assume to be 14 to 16 psi. It didn't want to fit the plastic tank radiator that I put in today so I stole one off a WJ that is sitting in the shop. 21 psi is OEM pressure for that system.
Either way, I'm not letting it get hot enough to blow pressure. Don't want to compromise the engine. It hasn't gotten over 240.

Something to think about: A WJ 4.7 requires a 21 psi cap, 16" electric fan and a mechanical fan w clutch. I have 1.2L more engine.
 
Something else

xj 4.0 rad core surface area: 341 sq in
wj 4.x rad core surface area: 483 sq in
ram 1500 5.9 rad core surface area: 589 sq in

All described as HD cooling / max cooling.

All similar construction; plastic tank, aluminum single row 1" core
 
Then I would definitely look into getting a fixed blade fan and a full shroud then. I had this same problem with my Nova, and I just went primary Mechanical fan and I had a secondary puller fan for when I was stuck in traffic that was controlled by a thermo-relay. Since I did most of my driving on the highway, once I removed the pusher fans from the front of the radiator, the temps never got above 200* on a 13:1 compression 377 with a 250 shot. And that was with a cheapo Griffin single row radiator from Summit.
 
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Another thought....your water pump pulley isn't the same size as your crank pulley, is it? Any aftermarket accessories that would slow down the waterpump rpm at high speed?
 
Digger87xj said:
Something else

xj 4.0 rad core surface area: 341 sq in
wj 4.x rad core surface area: 483 sq in
ram 1500 5.9 rad core surface area: 589 sq in

All described as HD cooling / max cooling.

All similar construction; plastic tank, aluminum single row 1" core
Click to expand...
Now you are talking!

Are any of those other radiators set at an angle? Granted it's old school, mechanical fan, technology, but a few degrees off vertical was the norm for heat transfer. I don't really notice that on the XJ.

Have you tried turning on the heater to see if it pulls the temp down?

I think that if you told time2getdirty you need a bigger radiator instead of a recessed winch, he'd git-r-done!
 
Any chance you could put smaller radiators or failing that, heater cores under some hood vents with pusher fans and get a little more cooling capacity? That's probably what I would try next. Don't know that a V8 will leave the space available for such an idea though.

Is your trans cooler built into the radiator or separate?
 
Turning on the heater doesn't bring temps down but it does steady them and help from climbing higher.

Kastein... looking into something like that. not sure where to place them though. There is quite a lot of room between the rocker protection and the frame. Maybe some looped DOM with cooling fins welded on just for more water capacity. Even a custom made heat exchanger to fit with protection.
 
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