maximize 360 summer coooling

[EasTXJEEPER]

On a recent 60 mile hot summer day trip I had to run the heater on high to keep the temp gauge in the green. Really dumb on a FSJ with AC I can't use.
Obviously something is haywire with the cooling system on my 83 Cherokee.
Where do I begin bugging this situation out? New Hoses and 180 degree thermostat and 15 # radiator cap plus the Radiator was pressure washed real good before this last summer trip.
As the second owner I believe all components in the cooling system are stock or equal to original.
I have driven this Cherokee for several years, running the AC in hot weather, with no cooling issues.

[rang-a-stang]

Do you have a stock/clutched fan?

[EasTXJEEPER]

Looks stock to me.
I have been following the previous posts of cooling problems with a 401 engine

[440sixpack]

Most of the time it's the radiator. radiators today are throw away but there used to be radiator shops all over for just the reason you're describing.

[EasTXJEEPER]

After pressure washing this radiator it is not a throw away. It is made of BRASS

[FSJunkie]

Was the radiator flushed internally? Saying it was pressure washed makes me think it was cleaned on the outside but not the inside.

Fan clutches go bad and cause problems.

Condensers get bent fins and block airflow.

Blocks will up with mud and rust.

Water pump impellers rust.

[EasTXJEEPER]

Since cruising at 60 to 7o with the heater wide open provided enough additional cooling to the entire system to keep my temp gauge on the very low side of the green for the next 60 mile trip home. I'm Thinking a cooling system flush is my next move.
I don't want the embarrassment of yesterday when parking at a show, Turned off the engine and in just a minute or so the radiator blew its top sending up a plume of stem under the hood and loosing more than a gallon of liquid coolant under the front end. It was like the return hose blew off. It took a while to open the hot cap safely. It was definitely HOT
I would hate to miss next Saturdays show at Emory Texas with cooling issues. Over 250 cars showed last year and I had the only FSJ. This 2dr wagon get lots of lookers wherever It show with its New paint and fresh Laredo pinstripes and survivor interior.

[joe]

35 year old radiator? Odds are good it needs to be rodded out at a shop or even recored especially if it hasn't been flushed and coolant replaced on a regular schedule. Coolant and brake fluid systems are prolly the most maint neglected systems on a car. "oh I got some so it's all good."...wrong. Pull the rad out and take it to a rad shop. They can weigh it and tell if it needs cleaning out.

[rang-a-stang]

wish you were closer, I have a good brass rad sitting in my garage for sale. shipping would make it not worth the $$.

[babywag]

I?d bet on radiator as well.
My first FSJ was a Cherokee that always ran hot and sometimes overheated.
My sister overheated it so bad once it blew a head gasket.
My dad must have flushed it a dozen times.
When it became ?mine? I put in a new radiator and it was fixed.
Never ran hot or overheated again, and being a young kid was pretty hard on that Jeep.

[rapom]

I tried this today and it worked great. But I still have a low speed problem. Probably need get the severe duty thermo clutch which will engage at lower rpm's

http://www.stl-vettes.com/65vette/co...tch_adjust.pdf

Here is some more useful information.

For cooling a stock 401 a 18" 7 blade high pitch 3-1/4" pitch like out of a 1977 caddy el dorado with a 472 v8 seems to be adequate matched to the stock shroud especially with a 180 mr gasket or robert shaw high flow thermostat. (stock fan is 16-7/8" or 17" 7 blade with a hair under 2-1/2" of pitch, another fan is from a 1981-1986 Cadillac with the 4.1L v8 it is 7 blade an 18 inches also with similar pitch right at 3" and moves a lot of air) i moved the MORE motor mounts up almost an inch since i have a 1" body lift to clear the 18" fan in stock shroud. Since i was going for a flat belly pan with my clocked dana 300 things needed to be shifted little any ways i re=drilled the more mounts 7/8" up and 3/8" for ward sliding the motor slightly ahead helped with valve cover clearance at the fire wall, moving it up allows you to continue using the stock radiator shroud.

I used a Hayden Severe duty fan clutch #2797 (buick with the diesel in the early 80's on some models like napa i had to notch the holes just a smidge to clear the bolts into the water pump but on a summit model i didn't, it was slotted deeper with universal slots). Also these fan clutches need some adjustment they like to engage at 210-220. Read this article about thermostatic fan clutch adjustment

I run 30% dextron synthetic coolant and 70% Distilled water with a 180* mr gasket high flow thermostat. Iw as running a 4 core brass radiator but recently on ebay there were some aluminium radiators for $139 + shipping another $30 called champion aluminium radiators, 3 row (3- 5/8" tubes) that are down flow and bolt in. for the price a good deal and seem to be providing good results for me.

I also changed to a synthetic motor oil 20/50 found i shed another 5 degrees across the board in engine temps.

Consider Evans NPG if you are having major cooling issues, check into it if you are really diggin for a different option to cooling. heard alot of good results i pondered looking at it in my jeep but so far the caddy fan with the ultra cheap aluminum down flow radiator seems to be sufficient

[EasTXJEEPER]

Grill is out exposing a black tranny cooler and the condenser. A small patch of condenser fins to open up. Done.
Pulled the Rad for a trip to town Tuesday. Looks great. Pulled the fan and China fan clutch.
Maybe a better air mover fan could help but not much at 70 MPH. That is where I was getting hot and turned the heater on hgigh. Retiming may help .

OT. Bought a 60 Lark VIII new in 60. Ran it 8 years with NO FAN summer and winter.. First thing I did was pull the fan to hear the Quad open up. Fan was in the trunk when I traded it for a low mileage 66 Buick Skylark and moved to Texas in 68. I loved that little green Studebaker hardtop and wish I had it back. I needed to turn the heater once or twice if summer Chicago Traffic slowed me down

[440sixpack]

Nothing you do is going to help if your radiator is plugged. rod it, recore it or replace it.

[thumperjohn151]

Been there. . . Dun That. . .

1st ? I am no expert, but I been turning a wrench for 50 yrs. I am a troubleshooter by nature, and profession. I collect and restore classics from the 50?s & 60?s ? So here?s my 2-bits ? I rebuilt a FE block Ford (300+HP stock) ? as you may, or may not know, rebuilt Fords are NOTORIOUS for running HOT after being rebuilt properly. So I started down the road to solving the problem ? 4-core HiTine radiator (next step up was an Aluminum NASCAR), HP fan, fan clutch, HP fan clutch, no fan clutch, New T-stat, low temp T-Stat, no t-stat, custom built WP, custom pulley (smaller to turn the fan/pump faster), shroud. . . . After a year, and $1000+, there was no Joy in Mudville. . . One day while at my parts house, on an unrelated matter, while commiserating with my parts guy, a customer who overheard our conversation stepped forward and offered his $.02. . . He said ?I know what?s wrong, and I know how to solve it?? ?I?m listening?? He said what you need is a Robert Shaw High Performance Thermostat, and here?s why - He proceeded to explain the inherent design defect in the stock T-stats and how the system REALLY works (details if you request) ? Short story is the stock T-stat isn?t keeping the coolant in the radiator long enough to draw off the heat!! OK, for $12 I?ll try one. . . PROBLEM SOLVED!! Idling in 100+ temps (Dallas TX) with the AC blowing 40degs. It might go up 5degs from the set temp. It also runs at set temp in 0degs. Going forward, I?ve installed these in all my cars/trucks as I go through them with success, including my ?87 GW 360 (which suffered the design defect of Vapor Lock ? installed a 5psi electric FP all the way in the rear to ?PUSH? the fuel). Robert Shaw was bought by Mr. Gasket. Your temp should not swing wildly ? maybe go up a few degs. When pulling a long steep grade. Good Luck!!

[Mr Carts]

I out in the middle of the Mojave Desert for 3 months it is 105 is a cool day we see 115-118 is normal. Here is how I keep my 80 FSJ Cool.


Everthing in the cooling system has been replace Radiator, water pump, 165 thermostat and hoses. I use water souble oil in the water and a zero pressure cap with a one gallon overflow tank.

A Conture fan is used in place of the stock fan.

I have a 24000BTU AC Unit with a AC Condensor that is huge and covers the whole radiator along with the factory tow package trans cooler that sits in front of it.

There are 2 heater cores beside the stock one: A CJ 5 mounted where the drive side pie plate would go, the second is a Ford Econoline rear heater mounted below the radiator both flow in series thru the factory heater in to the block.

On a 115 day the temp gauge will get a little past half way running down the road with the AC blasting.