megannelson58

I'm considering putting an aluminum radiator in my Jeep to help with overheating. Just wondering what everyone thinks of aluminum radiators and if it would help my overheating issue. (has new thermostat, water pump is just fine, I have gone through the entire cooling system.. Radiator is last on the list! I'm hoping that will fix my problem)

btm24

This link should help out and good luck on the overheating issue!

http://comancheclub.com/topic/38151-...ement-options/

Brandon

Eliminator91

Just did the Griffin conversion for my Stroker. Very well made, but expensive radiator. a bit of a bear to install, but it made a big difference. It is about 1/3 bigger than stock. Part No 5-591LB-FXX. Tube Size: 1.25", Core thickness: 3", No trans cooler. She never overheated but could get into the 3/4 mark in traffic on hot days. Now the temp is much more predictable. Tried the cheaper 2 core and 3 core from Radiator Barn. Still a small radiator. At the end of the day radiator size matters with cooling. This thing is about as big and you could fit in the space without serious hacking. Oh and hi, new member to the forum, but long time Comanche owner and restorer !!

RWKHausSupply

I did a American Eagle all Alum radiator in my Ultra 4 race jeep with the big stroker and high compression. Given everything is new. But even during the Glen Helen race where everyone told me that the biggest killer there is heat and watching gauges, my jeep never got over 210, and the t-stat is a 195. We are talking floored for 75% of the time and full brakes the rest.

It was explained to me (and makes great sense I think), that in a situation where you are always going fast when it might get hot, then the rad can be a Thick 3 core, since the wind is helping eliminate any static pres drop of the fan trying to draw cool outside air thru it.

In slow moving situation (pure crawling or traffic) a reg 2 core is good, because the fan has less static pressure drop trying to draw the air thru the thicker rad and more dense fins, and cools better then a 3 row.

In my situation where its both, I did a Thick 2 row, what they recommended, since it was more surface area then a reg 2 row, yet not as dense as a 3 row. And I have Never ran hot. Not in a race, not while driving to get my son at school, or even just in the desert idling and crawling.

People have lots of luck though with both 2 and 3 row all alum radiators. This is just what the manufactures engineer explained and seems logical and proved right for me.

Oh and American Eagle has since discon. the thick 2 row for the XJ. But I think they still offer the thick 3 row in their Champion line. And they are made in Temecula, California.

megannelson58

makes sense... let me tell you a little bit about my jeep. it is a 1992 cherokee that was originally a straight 6 4.0. i recently had the engine rebuilt and made into a stroker and is now a 4.6. i haven't had a problem with it overheating until recently. (since the weather has been hot. i don't have any trouble with it on cool days) but with it being 100 degrees the last little while i cant drive it for long or it gets way too hot. when it overheats i run a hose over the radiator and it almost immediately cools down. so i am thinking my water pump is working just fine because it is moving fluid through. and makes me think the radiator is no good. the radiator is bigger than stock and i bought it brand new.. how much bigger i am not sure. so the radiator should be functioning properly. after the first rebuild i blew the engine because a bad crank was put in and it sat (with 50/50 in the radiator) for about a year before i had the company fix and rebuild again. so im also wondering if the radiator went bad after sitting for a year without being used.

so... my question is... do you think the radiator is my problem? and do you think i should replace it and what i should put in it. thanks for the post! i'm also new to the forum

exjay1027

when my stock radiator crapped out on me i bought the cheapest single row all aluminum i could and for normal driving it's absolutely perfect. temp never creeps over 200. gets a little hot while wheeling but i'll see if some hood vents fix that before replacing it.

so, yeah i suggest one and the nicer the better

Eliminator91

I totally agree with the 2 core vs. 3 core comments. The griffin is a 2 core which IMHO is the best compromise. A 3 core in the space available in the XJ makes for very thin cores. At the end of the day cooling is about how much surface you have that air can flow over and actually cool the fluid within.
Here is what I would check first:-
1. Check the a/f ratio. If she is running lean then that will cause the engine to run hotter. (Not likely if you are running 24lb injectors.) If you don't have access to an a/f meter then check the spark plug color. Only thing that will really fix that under normal non WOT running is bigger injectors or more fuel rail pressure. MAP adjusters etc only help with WOT where the PCM uses the sensors to control injector pulse. Under normal conditions the jeep uses a predefined fuel map than it tweaks using input primarily from the O2 sensor, other sensors do have a minor role. It is pretty rare I am on WOT in New York traffic.
2. Make sure your AC is fully charged. The less charge in the AC the harder the condenser has to work.
3. Always use a 195F thermostat.
4. Make sure your radiator cap is good. Even a small leak here will reduce the system pressure.
5. Installing a trans temp cooler external to the rad will help. I placed mine under the rad behind the bumper. There is some evidence that 5 speed XJ strokers stay cooler, which would make sense as the rad is not trying to cool water and trans fluid. My Griffin doesn't have a trans cooler built in.
6. Do the Taurus fan conversion, that fan is huge and pulls a ton of CFM.
7. 3 fan systems like what I have don't pull any more CFM than the stock system, they just do it more evenly and you have total control over when they are on or off.
8. High volume water pumps can help, but flowkooler doesn't really help, tried them twice, much better with a Hesco or 505 performance, both of which have a completely new impeller assembly with bigger fins.

Stroker's run hotter than a regular 4.0 simply because there is more rotational mass which generates more heat. going from 4.0 to 4.7 is a significant volumetric increase. (Bigger bore, stroke and bore size) - simple physics. The Jeep XJ cooling system is marginal. Mine never heats until it gets really hot in the summer and I am in traffic (which in NY is inevitable). If I turned the AC off it would usually perform much better.



The Stoker I had in my WJ never had a cooling issue because it was a bigger radiator and the WJ had a bigger opening as it was primarily build to cool a V8 not a straight 6, so it had some excess capacity.

Sorry to be so long winded.