I know that for my 80 CJ-5 with 258, visible factory HD cooling items included a 7 bladed non-clutch fan, a fan shroud and a 2 core radiator that had a higher fin count (IIRC, the standard radiator had 9 fins per inch). I believe cooling system capacity was still the same as the standard system. after the factory radiator went out, I changed to a 3 row radiator but all the years that I've owned it, I have never had any cooling problems even when driving in soft beach sand in the summer (90+ degrees ambient temperature). I did change to a 180 degree thermostat many years ago.

 

Here is a neat chart from the manual. Basically, the HD came with a better radiator, bigger fan, shroud, and clutch.

 

In 1976, the HD option unfortunately did not include the fan shroud.

 

Be careful with the 3 core radiator - reduces fan clearance by about 3/4 of an inch - if you run the 3 core you need to get a thinner fan spacer -- on daily driving the clearance is ok - but if you hit it hard off road the flex in the frame may let your fan eat the radiator - took me 2 radiators to figure it out - of course you could always go to the contour electric fan route

 

That's not a problem with mine. I'm running 3 row radiator with the factory HD 7 blade fan and have about 1 3/4" of clearance between the radiator core and fan blades. My fan spacer is 3/4" thick. I wonder why the difference.

 

The shroud and 7 blade fan make a bit of difference as would coolant recovery. I run my CJs on the equator and they can run hot but do not overheat.

One has the shroud and a 4 blade metal fan and a 2 core radiator and coolant recovery. It is fine.

The other has the shroud, a 7 blade fan and clutch and a 2 core radiator and coolant recovery. It runs a little bit hot.

The shroud is a no brainer, it will duct the air and increase the air flow substantially. It is a $5 piece of plastic or metal so go figure why you would build one WITHOUT a shroud. If you took the measurements of your radiator and fan (diameter and how far the centre was in from the radiator edge) you could find a generic shroud in a scrap yard. My 1981 has a generic POS shroud from something, the 1984 looks factory.

The other thing to do is to have the radiator inspected and flushed and check the system is holding pressure. They can run quite warm without any adverse effects but a fully functioning system will not allow the needle to rise at all. Also check the water pump bearings, if the fan flops around the water pump will need replacing and this helps cooling.

 

If your running ported vacuum for the vacuum advance on the distributer you could put it on manifold vacuum. It will run cooler at light throttle low rpm. You will need to low your idle with the idle screw if you do it.

 

If your radiator cap is in the center you need a standard shroud.

If your radiator cap is off-set you need the shroud for heavy duty cooling.

:cheers:

Jeff

 

Jeff, I think your talking about different radiator styles, not capacity ratings. 72 thru 80 used the centered radiator cap in both 2 row and 3 row core (heavy duty). Later models used the newer style radiator with the offset radiator cap and larger diameter fan.

 

Wow, what an intercontinental thread! Bali, Hawaii, US and now Oz. Just need some of those Austrian dudes to chime in and we're sorted. But I guess that aint gunna happen, they don't get hot over there do they?
My CJ8 goes from 0 to off the gauge and back in traffic but still goes super. Reckon that's just an electrical thing. Recently put my 7 back together and now it does the same thing. Whatever, maybe it'll miraculously go away like the rear main leak. That s h a t me completely for a while but now that it's gone I aint sayin nothin.

80CJ I'm looking you up, mate.

 

oops. Just went back and saw that 80CJ is the Hawaii guy and the Bali guy is Bagus. Sorry about that. What the hell, I like tropical islands I'll look you both up!

Hey 80CJ that's a funny looking jeep in your profile pic? Suppose it would go anywhere (almost).

 

I like the large fan on it. No overheating problems! I've always liked those WW II Vought F4-U Corsairs...neat airplanes.

Edit: Oh, the profile pic. That's a DeHavilland DHC-3 Otter. We used it on a fly fishing trip to Admiralty island in Alaska. That thing gets off the water amazingly fast. The comment about the large fan applies here also!

 

I speak Austrian, does that count?

 

You're in!
hey I just told a joke on the other thread, I'm still laughing. kinda uncool to laugh at your own jokes but hey, who's watching? Not the "cool" police for sure.

 

Anyone running a solid fan should inspect the blades where they attach to the fan arms at the rivets.
You'd be surprised how east they crack their from flex.
Even the factory 7 blade with the fan clutch will crack.
Just be advised and check yours frequently, even if you have to pull it off because the cracks will appear on the front side. Look for small lines of rust which will form from metal fatigue.

 

Look for small lines of rust which will form from metal fatigue.

Thats a scary thought. I have my arms in the engine compartment all the time while the engine is running... tinkering, etc.

However, the blades seem pretty tough. Last summer my klaxon horn broke off its mount, and landed on the blades, making a wicked racket... nothing broke

 

Mine came originally with 2 core radiator with centered cap, fan clutch and coolant recovery. I'm not sure if my shroud is still around or not. Need to check the shed out back. I know that I want to put it back to stock and remove the flexfan that I put on it some time back trying to fix an overheat issue that turned out to be the motor going south. So there are HD cooling with side cap and center cap?

 

How does the recovery bottle help with cooling? My 80 CJ5 is overheating if I drive on the freeway for more than a few miles on hot days. It has been recently flushed and I have a new 180 deg thermostat and housing.

Thanks for any thoughts.

 

Thanks for the info

Thanks for the info. Seems i have a combination of parts. Not unexpected given the pedigree of this old jeep. We will try a shroud and see how things go.

 

Is there a heavy duty clutch? Or are all the clutches the same just different rotation?

 

There are several different part numbers but there is only one clutch type. It can confusingly be called "fan drive, heavy duty" but that is because it is part of the HD pack, not because it is any different. The alternative is fixed.

 

 

K thanks

 

Anyone know why my "HD" Cooling shroud doesn't sit flush with the mounting bolts on my 3C radiator? Its not getting hung up on the fan at all, so is this maybe not the right shroud? thanks

 

I've been wrong before, (many times) but I don't think your radiator is a direct factory replacement. I'm not too familiar with your year, but your filler I believe should not be centered but on the left.

What is hanging up?

 

The bolts should go though the shroud and the radiator.

This is when I had the motor on the test stand, but you get the idea.

 

Funny this thread just came up because as I was replacing my intake/exhaust gasket we started taking other things apart (which always seems to be the case) and found my radiator mounts were broken and the shroud was too.

I ordered the shroud with HD cooling because that's what was in there before.

Here's where I ordered it from:

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1181326&parttype=10707

I also have the center mount radiator. Quadratec has a radiator for $330! I'm going to look locally for one. I've looked at other websites and can get one for up to $100 cheaper. We'll see what I can find.

CJ7ROB it looks like all of your shroud mounting holes line up. What's keeping it in there and what's preventing you from using the mounting holes?

 

Yeah its an aftermarket radiator, definitely not original. I know the bolts are supposed to go thru it, but the problem is the shroud doesn't reach the radiator where it bolts in even when you push on it. Right now its just laying in there not bolted. Its almost as if its not deep enough.

 

ok guys......
I read all posts.
But how can I understand which one shroud to buy ???

On my '83 258 I mounted his original rebuild radiator w/center cap (and 3 rows) and the engine has a Flexalite fan (not electric fan).

I repeat: shroud for hevy duty or not?

I apologize if I missed something.......