Mike Mc

Guys and Gals. I'm hoping to take my PW and 2 trailers back to Wyoming next week. So I took the 24K GVCW on a test tug this hot weekend and the truck was getting hot. Reached 220 deg. on a 8% grade so I pulled over for it to cool off.

The truck has 5.38 gears and the Brownie is in under drive, 47RH in second gear with torque converter locked up is about 27mph at 1,900 rpm. It takes a while to heat up running at this rpm. But if I rev it a few hundred more rpm the temp gauge climbs quickly. While the pyrometer is only at 900 deg.

Running down the highway at 60mph, Brownie in direct, auto in OD is 2,000 rpm. With it being a 100+ outside the truck runs about 185. But if I speed up to 67 @ 2,300 rpm the water temp starts climbing again. At 2,000 rpm the pyro reads about 700 with 20 lbs of boost. At 2,300 rpm the pyro comes up to 900 and boost is about 28psi.

If I run this truck above 2,000 rpm why does it get hot?

comotionman

Fill out your sig. We need to know about your truck. What is it? To me it looks like a w500/w600 etc. What is it? Whats the gvw of the truck? What axles? What size tires? What engine? Injector pump? What intercooler? Trans cooler? What size radiator? Size fan blade?

Alec

You need a bigger radiator, OR to retard your timing.

Retarding your timing will give you a little worse mileage, a little more smoke, higher exhaust temps, and less heat rejected into the water jacket.

I realized that "a bigger radiator" isn't really what I meant: I just sort of assumed that you were sure the radiator/cooling system was working at its best efficiency. Have you measured temp @ inlet & outlet of radiator while driving? to determine if you have some sort of coolant circulation problem like a bad t-stat or other restriction, or if the radiator is simply failing to reject enough heat. It is possible there is some sort of air turbulence problem at certain speeds, that is keeping air from flowing through the radiator, or air hot air back around and through the radiator recirculation problem, though this is unusual at highway speeds. Also -- are you using the oil to water heat exchanger for the new automatic transmission? And, if so, what are your transmission temperatures during these tests . . .

bannerd

bad tstat? I just throw mine in the trash.

cougar

The trouble with transplants is there are a lot of factors that people don't consider. The main one always seems to effect cooling, weather it be engine of transmission temp.
Do you have the right radiator? Not only for the engine, but the vehicle it is in.
Do you have a fan shroud? Makes a big difference in getting the air through the radiator.
Air flow under the hood? This is always a good one. Back pressure created by turbulence or restriction check the air flowing through the radiator.
Is inadequate transmission cooling transferring heat to the engine via the heat exchanger?

BILTIT

On long pulls with my setup (from the other thread) i can watch the engine temp start to slowly climb. This is at 30+psi and ~1800rpm (hefty on the throttle in 5th gear).

Usually when i get more rpm i will cool but yours seems to be the opposite, might be just overtaxing the cooling system.

I would start checking air/water flow through the rad etc. You might just need better airflow paths

Mike Mc

I took the two electric pulling fans off and put on the manual clutch fan with a homemade shroud. After climbing the steep grade it would never get over 201F. So the over heating problem has been solved. BUT the Car Quest fan clutch never disengages. Coming down hill exhoust temp was 200 and water was 175 and it roared and roared the whole way. I waited till evening time to drive it in the cool weather without a trailer and the fan never disengaged.

I called our local Dodge dealer to get a fan clutch but they said it was discontinued. Can you all recommend somewhere else I can maybe get a better quality fan clutch from?

NJTman

This is the fan I just put on my truck this year.

So far, flawless operation...




BTW,

I am SOOOOOOOOO Jealous of that truck you have there. If that sucker was in blue I'd sell my wife to buy it from you.....

bobva

whats your radiator elevation in comparison to the motor?

When others do a body lift that raises the radiator elevation from stock. which cause poor cooling. when they lower the rad back to the proper elev it cools properly.

PapeCAT

Good day, Mike MC: (I am a MC also)

I had a problem with new fan clutches as well, they did not want to disengage,and I returned a napa unit because of this.

What I found out, was that the new fan clutches are so "tight" that they will not drag enough to disengage. The new clutches seem to be engaged all of the time. However, there are two different fan sizes for first gens, with the later intercooled model trucks having a larger fan. You NEED the larger fan to provide the required drag to freewheel these new fan clutches. the non I/C smaller fans won't work. Just an FYI.

So - What fan are you running?

Mike Mc

Blue ! For me to paint this thing blue you O lady better be a super model!

The engine does sit low. My homemade fan shroud was challenging to make because the engine sits so low.

The 5.9 is a 93 inter cooler model. Hopefully it has the bigger fan. Sure sounds like the bigger fan. Tiring listening to it all the time.

Maybe I'll try the Hayden fan posted above. Also have the original fan clutch that came on the engine when I bought it from a wrecking yard. Took it of cuz it showed signs of leaking oil. Maybe I should put it back on and see what happens??

NJTman

More like a "menopausal" model....




What frame do you have in that beast ? Is that a 93 truck frame, or something fabbed up, or the original frame from the hulking beast... ?

Twitchy

MikeMc,

Were you on 4btswaps before you joined DTR?

Your truck looks very familiar.

Alec

I'm glad that you solved the cooling problem. I didn't remember that you were using electric fans. I tried using an electric fan on my Jeep swap, and had exactly the same trouble: High temperatures at highway speeds. It took some digging, but I discovered that the truck cooled better with the fan turned off at higher speeds. I ended up having to move the radiator forward & squeeze in the OEM clutch & blade, which solved all the problems. I haven't fooled with electric fans since. Another way to look at it is that a mechanical fan can draw 10+ hp -- no electric fan has a motor even close to that.

As for the fan clutch: I got tired of replacing aftermarket clutches, and bought one of these: CUMMINS FAN CLUTCH 4936007. I managed to find one for $70 shipped. I haven't done the install yet, but I am sure you could fabricate the required parts, and I think it will provide the best of both worlds.

Other than that, I would try the clutch that came with your donor engine, even if it is a little greasy. I've seen a few that worked well, despite looking as though they were toast.

And I do love your truck! Yellow & all . . .

j_martin

Is there a flex fan that will work? Concept is simple; pulls a big bite of air when going slow, blades flatten out at speed and unload torque, but still move a ton of air. Would be a bit more noisy than a clutch fan, but quieter and less power hungry than a fixed blade and drive fan.