Cooling upgrades

Chi-Town

The guy under the car
That's just it, pure water has one of the highest thermal transfer rates available. The things that rate higher aren't really usable in a cooling system.
 

Dan Grec

Expedition Leader
The rad in my '96 XJ was rusted so badly it needed replacing.

It's very easy to test:

Drive around on a hot day until the engine is up to normal (or higher) temp.

Turn the engine off, and use you hand to test the temperature of various parts of the radiator (watch out for hot spots). In mine, it was very obvious that ~50% of the rad was bone cold showing that the hot water was not circulating properly. A replacement is easy.

-Dan
 

OttawaXJ

Observer
Griffin Radiator, Cut hood vents, make sure your water pump is in good shape. And I'd tone down the anti-freeze mixture. We use 50/50 up here in Canada, down there you would probably be able to run just straight water most the year. I'd suggest 70/30 Water/Antifreeze. That'll help alot with cooling.

In the summer(May to Sept) I run 70/30 mixture, around mid september to later april sometimes like this year, I run 50/50. Huge difference in cooling having proper mixture. you should be replacing your coolant every 6 months anyway.
 

Septu

Explorer
Please correct me if I'm wrong... but water has a boiling point of 100F. Jeeps normally run around 200-220F. Don't you need the AF to keep the water from boiling?
 

SouthPawXJ

Observer
Water boils at 212 F at 14.7 psi (standard atmospheric) pressure. As you increase the pressure, the boiling point of water increases (this is how a pressure cooker works). Most coolant systems run with a pressure greater than atmospheric pressure (which is why you can't take the pressure cap off the radiator after driving). Water has a higher specific heat than ethylene glycol (which is a large component in antifreeze), but freezes at a higher temperature than antifreeze (hence why it is called antifreeze).
 

dlargo

Observer
thanks everyone....gonna keep an eye on it and see what happens. I may replace the electric fan as it leaned into the pulley and was eaten up a bit.

Danny
 

madmax718

Explorer
Water alone is the best heat transferer- but it also suffers from a low boiling point, and a low freezing point.

Reasonably speaking even if you ran just plain (distilled!!!) water, your engine should run just fine. As someone mentioned, pressure helps keep it from boiling, and thereby cools better.

a 50/50 mix is probably the best overall application- Just depends on where you are. On top of that, you really want the anti corossive additives that are in coolant. It helps keep the aluminum and steel from killing each other, and also from clogging up your radiator. most of the time, you should probably at least do a drain and fill on the radiator every few years- or every 5, depending on the brand of coolant. More doesn't hurt. Coolant flush also helps loosen and release debris from the radiator core. Add shortly before you do the drain and flush.

lastly... DISTILLED WATER!
 

dlargo

Observer
I try to drain and fill each year...beginning of summer. Cheap insurance. I always use distilled water and a 50/50 mix. On a side note just changed the oil with a drain and fill of trans fluid with some new plugs and on fill up this morning got 19.2 mpg. Just one tank but nothing changed in my driving or where I go each week....

Danny
 

DaveInDenver

Expedition Leader
Griffin Radiator, Cut hood vents, make sure your water pump is in good shape. And I'd tone down the anti-freeze mixture. We use 50/50 up here in Canada, down there you would probably be able to run just straight water most the year. I'd suggest 70/30 Water/Antifreeze. That'll help alot with cooling.

In the summer(May to Sept) I run 70/30 mixture, around mid september to later april sometimes like this year, I run 50/50. Huge difference in cooling having proper mixture. you should be replacing your coolant every 6 months anyway.
This is a great point. Anti-freeze is a poor coolant, so run just enough concentration to meet your low temps. Pure, distilled water is great as a coolant, although anti-freeze does have some anti-boilover, anti-corrosion additives so you should run a light concentration just the same.

I also agree with madmax718 that a cooling system flush might be a good idea. I did that to my truck when I bought it and there was a lot of scale and gunk in the system. Even the most diligent owners sometimes don't know to use distilled water and with Toyotas (I know you have a Jeep) it's not unheard of for someone to mix the factory red coolant with standard green, which makes a slimy soup when they mix.

I installed one of those Prestone flush kits and used the additive. I followed the process they described up until it wanted me to refill the system. I add several flushes with distilled water before re-filling with coolant just to make sure the tap water from the hose is well diluted.
 
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If you do plan to go with an aluminum radiator I have a less expensive alternative to the Griffin radiator. We run this same 3 row all aluminum radiator in our JeepSpeed XJ and we have never had a cooling issue, biggest plus is they come with a life time warranty and start at a fraction of what CBR and Griffins run.
 

Chi-Town

The guy under the car
There are a few alternatives to the Griffin out there but the cross flow set up works amazing. Flex-a-lite makes a nice unit too. A slow drive down a trail is a lot of work for a cooling system compared a constant speed race (I wish I had the budget to build a JS :( ).
 

Krytos

Adventurer
I spent a few weeks chasing down cooling gremlins in my LJ. It wasn't running all that hot, just north of 220* at high speeds. I ended up replacing some parts, and rinsing out my radiator, both on the inside and the outside, and installing a 195* thermostat and a new fan clutch and was able to pretty much cure the issue.

One thing to remember, anytime you've ever driven through muddy water, it dries on the fins of the radiator. If you don't rinse it off pretty quickly, it's extremely stubborn to get off, and interferes with the cooling.

Does anyone have any experience with pusher fans? I'd like to have a fan out infront of my radiator for those times when I'm idling or running at low speeds, like when running trails or wheeling rocks. I would run it on a switch.
 

jeep-N-montero

Expedition Leader
I spent a few weeks chasing down cooling gremlins in my LJ. It wasn't running all that hot, just north of 220* at high speeds. I ended up replacing some parts, and rinsing out my radiator, both on the inside and the outside, and installing a 195* thermostat and a new fan clutch and was able to pretty much cure the issue.

One thing to remember, anytime you've ever driven through muddy water, it dries on the fins of the radiator. If you don't rinse it off pretty quickly, it's extremely stubborn to get off, and interferes with the cooling.

Does anyone have any experience with pusher fans? I'd like to have a fan out infront of my radiator for those times when I'm idling or running at low speeds, like when running trails or wheeling rocks. I would run it on a switch.
Or you could just upgrade to the 2 speed Taurus fan....
 

Krytos

Adventurer
Honestly, I'm more than happy with my mechanical fan setup, especially now that I worked out the issues I was having. I'm just looking for something to supplement both my vehicle and A/C cooling for those days when we're moving reeeaallll slow, and heat becomes an issue.
 
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