Aftermarket Radiator

Once again, a search proved fruitless. I apologize iun advance since this issue has undoubtedly been covered, but I'm upgrading my '91 XJ with an aftermarket radiator and water pump. I've read that aluminum radiators are more efficient, and a higher volume water pump swap at the same time makes sense to me. Anytime the ambient temperature gets over 75 my XJ runs hot, like near the red on the temp gauge. Anything above 80 and it's into the red. I replaced the radiator with a stock one five years ago, so I doubt the current one is too plugged up. What brand aftermarket radiator and water pump would you recommend for a '91 with a 4.0 and AW4?

http://www.naxja.org/forum/showthread.php?t=81138&highlight=radiator+water+pump

Literally 5 seconds.

Aluminium is not more effiecent than copper. The standard Jeep radiator is aluminium core with plastic tanks.
Here are facts for you given by a couple of persons on AJOR:
The thermal conductivity co-efficient for Aluminium is 205-237 W.m-1.K-1 and for Copper it is 385-401 W.m-1.K-1. Yes - it is almost double, but there a couple of other things to consider here. The heat inside the engine is being transfered from the combusion chamber and friction surfaces mainly through cast iron - which has a thermal conductivity co-efficient of about 55 W.m-1.K-1 and carbon steel (36-54 W.m-1.K-1) and then to water (about 0.6-0.8 W.m-1.K-1 depending on addatives).
Let's assume two cooling systems equal in every way except one has a copper core and one has aluminium. Since all is equal the flow of coolant (driven by two equal pumps and equally opened thermostats) is exactly the same speed or volume per unit time. Let us also assume the initial coolant temperature is the same. For simplicity's sake lets say the temperature is being measured in Joules (it is after all just thermal energy) and it is around 1000J.
Now as that coolant passes through the core for a unit time, the core might accept say, 300J in each of the systems. Again for simplicity's sake lets assume that both of the systems has passed about 1kg of coolant through their respective cores in that unit time.
That means that the 1kg of coolant with the cooper core will have dropped temperature by 0.85K in that unit time. The coolant with the aluminium core will have dropped in temperature by 0.33K in that same unit time. That's why I said the copper core will cool down the coolant faster than the aluminium will.
Remember too that for every drop in coolant temperature there is a corresponding increase in core temperature. If the core is then also rising in temp faster, then it will more quickly reach a greater difference in temperature compared with the surrounding air. This in turn provides a faster rate of cooling the core because of the exponential rate of cooling quoted in Fourier's law.
So.............in any one unit time, while the same quantity of coolant has passed through, more heat has passed out to the surrounding air via the core when Cu is used when compared with Al. Copper is faster at cooling.

Yeah. That's why every single person in any kind of motorsport runs an aluminum radiator. Do you think John Force has a copper radiator? How about Jeff Gordon? Copper is weak, aluminum is strong. Copper is heavy, aluminum is light. A 2 core aluminum radiator will out cool a 4 core copper brass radiator all day everyday.

Why? Airflow. It is easier to flow air through 2 cores than 4.
So why would an aluminum 2 core out perform a 2 core copper radiator?
Because copper is weak. After it bends and flexes it will flow very litte air or water.

Think of it like this.
All the wires in your Jeep are made of copper. Why? Because it is easy to bend and has all the properties that GoJeep spoke of.
Are your rims made of copper? Of course not they have to be strong.
Is your stereo amplifier made of copper? Nope it's aluminum because it has to be strong and disapate heat.
If copper is so great why can I buy an aluminum head and run 11 to 1 compression on pump gas or use an Iron head and run 10.5 to 1 compression on pump gas? Why can't I buy a copper head and run 13 to 1 on pump gas? :sure:

imis_idora said:

Yeah. That's why every single person in any kind of motorsport runs an aluminum radiator. Do you think John Force has a copper radiator? How about Jeff Gordon? Copper is weak, aluminum is strong. Copper is heavy, aluminum is light. A 2 core aluminum radiator will out cool a 4 core copper brass radiator all day everyday.

Why? Airflow. It is easier to flow air through 2 cores than 4.
So why would an aluminum 2 core out perform a 2 core copper radiator?
Because copper is weak. After it bends and flexes it will flow very litte air or water.

Think of it like this.
All the wires in your Jeep are made of copper. Why? Because it is easy to bend and has all the properties that GoJeep spoke of.
Are your rims made of copper? Of course not they have to be strong.
Is your stereo amplifier made of copper? Nope it's aluminum because it has to be strong and disapate heat.
If copper is so great why can I buy an aluminum head and run 11 to 1 compression on pump gas or use an Iron head and run 10.5 to 1 compression on pump gas? Why can't I buy a copper head and run 13 to 1 on pump gas? :sure:

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I think what GoJeep was trying to say is this:
Copper has a better thermal conductivity with a liquid than aluminum. It simply transfers heat better. It does not transfer heat to air as well as aluminum does, but because of the amount of surface area inside the radiator in contact with the engine coolant, it becomes more efficient at reducing the coolant temperature because it absorbs the heat from the coolant at a faster rate than aluminum would. Then the disadvantage that copper has at transfering that heat to the open atmosphere is outweighed by its ability to transfer heat from the coolant and return it to the engine.

Your comparison to motorsports doesn't ring true. Jeff gordon gets a new radiator every week, so it doesn't have to last the lifetime of a car and he travels at 180 mph, so the airflow through the radiator outweighs aluminum's less efficient manner to absorb heat from a liquid. I've watched a lot of NHRA on sunday nights and I couldn't find a radiator on the front of a funny car anywhere.

Take a look a computer processors heatsink. Little copper core to transfer heat from the processor imbedded in an aluminum block to transfer that heat to the atmosphere. Best of both worlds.

CSF, 3 row radiator. Like $120 delivered. I got it, I love it.

Sincerely,

A very non technical answer.

I bought a be-cool rad from summit racing (499.00) back in July and it started leaking last week. I sent it back and a replacement is on the way. PITA

RickyN29 said:

CSF, 3 row radiator. Like $120 delivered. I got it, I love it.

Sincerely,

A very non technical answer.

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Got a link?

http://dpgoffroad.com/

Use the side links on the left to go to ENGINE and they sell the CSF 3 core

Also a great company to deal with.

Bouncy said:

http://dpgoffroad.com/

Use the side links on the left to go to ENGINE and they sell the CSF 3 core

Also a great company to deal with.

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I found it on DPG's site. But I didn't see anything about $120 anywhere.

Hale

Haleyes said:

I found it on DPG's site. But I didn't see anything about $120 anywhere.

Hale

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I got mine for like $120 from there if I remember right. I installed mine last spring.

http://www.radiatorbarn.com/s7.asp?ac=Y&year=1999&make=JEEP&model=CHEROKEE&submodel=XJ&engine_size=L6%2C4.0L%2C242ci

Heres the one for my Heep, all metal

raypla said:

http://www.radiatorbarn.com/s7.asp?ac=Y&year=1999&make=JEEP&model=CHEROKEE&submodel=XJ&engine_size=L6%2C4.0L%2C242ci

Heres the one for my Heep, all metal

Click to expand...

What brand is it?

Haleyes said:

What brand is it?

Click to expand...

I don't know. Its all metal, sides, and they're well talked about. Thats where I intend on getting mine.

1800 252 0333 auto radiator outlet modine heavy duty two row all metal construction part #1193-3PL lifetime warranty
had the same problems
get a heavy duty two row this whole three row thing well..in my own exsperience I have had them. Some folks have good luck with them , not me. Anyway the two row has larger tubes for coolant to travel compared to the three row
the tubes on the three rows are so small ( have to be to make it fit in the limited space for the radiator in the xj) they are more likely to clog and well then you get dead or cold spots on the rad and well less efective cooling
switched to this rad cools great $150 to my door

or you may have to try 1800 radiator vendor # was 436020
it came in a modine box the sticker on the box said 3 row but I checked the # on the box vs my invoice vs the radiator in the box and all the #s matched however when I ordered it I asked for the heavy two row and I checked the core of the radiator itself it was in fact a two row and much larger in size than the three row it replaced so I did recieve what I ordered
for some reason the the lable on the box said three row but is was not.
sorry to be so long I was just real pleased for a change

The radiatior and water pump aren't necessarily the problem or solution. You may have a bad thermostat, fan clutch, or temp gauge.

There are a lot of posts here and on other boards about problems with various aluminum radiators....one problem is the "tubes" are narrow, water flow is poor in some of them.....the other problem is some of them have very close fin spacing....difficult to get air thru them.

I run Modine radiators........OH!!! And just where does John Force mount the radiator in his funny car???? I wanna see that!!!!!!!!!!!!!!!!!!!!!!!!!!!!

And I think GoJeep did an excellent tech explaination....even though I am Metric Deficit.

I got my radiator from NAPA...it was an exact replacement modine, all brass & copper. Cost me $106 out the door. cheaper than the online places AND i didn't have to add shipping onto that price either.

I run an aluminum one in my off road rig, and the tubes are not narrower than the stock brass & copper one, and it runs cooler also.

Some of the aluminum rads do have fins too close together tho.

MudDawg said:

There are a lot of posts here and on other boards about problems with various aluminum radiators....one problem is the "tubes" are narrow, water flow is poor in some of them.....the other problem is some of them have very close fin spacing....difficult to get air thru them.

I run Modine radiators........OH!!! And just where does John Force mount the radiator in his funny car???? I wanna see that!!!!!!!!!!!!!!!!!!!!!!!!!!!!

And I think GoJeep did an excellent tech explaination....even though I am Metric Deficit.

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So do I - have for years.

Granted, I don't much follow motorsports - but isn't an advantage of an aluminum radiator vice copper reduced weight for the same size? That means more of the acceleration is going to be used to actually accelerate, due to reduced mass (and therefore reduced inertia.) I think you'll find that most "motorsports" vehicle also run straight water - water is a more efficient thermal conductor than ethylene glycol, and therefore will work with the radiator and engine to conduct more heat. EG is added to automotive systems to prevent freezing, not to improve cooling.

I also hear you on the metric stuff - I still think in inches, and probably always will. Fortunately, there are "one-button conversions" on my calculator - I try to remember the conversion factors myself, but I've been hit in the head an awful lot, and can't trust my memory implicitly on some things any more...