Radiator for 7.3 diesel?

[12998]

Pulled my wheeling jeep around last weekend. The jeep and trailer go about 7k and the M715 is 6600 empty, so figure at least 14k being hauled around. Not a huge load but the biggest I've had since the diesel swap. Temperature was in the mid 60's during the run.

Definitely noticed that this cooling combo lacks the volume of the original radiator. Temp spikes quickly with the load, never see this when I'm running around unladen. On long hills gets to 220 or so and remains constant until the hill is done. Would like to see it a bit lower but seems to be fairly consistent. Might need to look into a larger overflow tank to handle the temperature swings.

She pulls really nice too! This rig is a tank and handles the trailer weight very nicely. The tongue weight made it ride so much better, might be rigging up a weight box behind the rear frame rail to use when I don't have a load.



Hope this helps.

Paul

[Mikel]

Very nice!

[Barrman]

What rpm are you at when it gets to 220°? That is a lot of weight. Maybe a downshift would get coolant flowing more and keep the temps down. Idi heads get really hot with high loads and boost.

[12998]

Barrman

I've pulled a lot heavier with similar combinations. The truck the drivetrain was taken from regularly pulled a gooseneck filled with hay bales that was about about 15k (goose is about 6k and 10 hay bales). Temp would creep up on long hill pulls but nothing like now.

I'm spinning it about 2000 rpm at hiway speed in 4th. This is about 60 mph. I can't tow in 5th. On really bad hills I was down shifting to third if I was going below 55, that is spinning the engine about 3000 rpm.

I have the ZF5-47, 4.10 gears and 11r22.5 tires which are about 41 inches tall.
The tires and the weight are hurting this combo but I really like them.
I need a bit more gear ... maybe 4.88 or 5.13. Future project.

My 7.3 is NA, no turbo.

[12998]

Mikel

Thanks!

I really like the combination.
Pretty much the coolest tow rig I have ever had.

[Mikel]

Mikel

Thanks!

I really like the combination.
Pretty much the coolest tow rig I have ever had.

Love it. How is it on fuel?

[12998]

Not as great on fuel as I expected. I've got a little over 800 miles on it since the 7.3 swap and been averaging between 10 and 12 mpg. The tank where I was towing was just under 10. Given the lack of aerodynamics in the body, the height of the rig and the very heavy tire/rim combo I'm ok with 12 mpg.

What kind of mileage do most of our rigs get?

[Barrman]

Stock I got 9 to 10 with a top speed of 48 mph.

Big Block 396/NV4500 and stock tires I was getting 12-13 running 48-52 mph.

396/NV4500 with XZL 11.00 tires got me to 54 mph cruising but never better than 10 mpg at that speed.

6.2/NV4500 running 52-54 gets me 13-16 mpg. I really haven't run an entire tank in 4 years of just going down the road. Lots of parades, idling in fields, moving stuff around town mixed in with 100 miles here or there driving.

[Mikel]

Not as great on fuel as I expected. I've got a little over 800 miles on it since the 7.3 swap and been averaging between 10 and 12 mpg. The tank where I was towing was just under 10. Given the lack of aerodynamics in the body, the height of the rig and the very heavy tire/rim combo I'm ok with 12 mpg.

What kind of mileage do most of our rigs get?

My 6x6 (6BT) gets about 13MPG. Highway is 65-70MPH. One time I got 15... Towing a car on a trailer on a long trip, go figure.

[12998]

I put on a lot more hiway miles than you do ...
I work 47 miles from home and have driven it to work 4 times in the last month. Pretty much the whole drive is at 65 to 70 mph, takes a lot of energy to push this huge brick thru the air at those speeds.
If I slowed down it would probably get close to what your 6.2 is getting.
Do you still have stock axles and gearing?