Engine performance

[V8srfun]

While driving home from the quarry with 10,000 lbs in the bed the truck performed perfectly except for the hills. One of the hills I was on I had to climb in low range and second gear. The truck would not hold rpm in third even with starting up the bottom of the hill at 2,400 rpm. My truck is a non turbo so I understand I may have a little less torque than the average deuce but this does seem to be a little weak.
My truck does smoke some in the lower rpm range but in no situation does it (roll coal) so I don’t think I am over fueling at all. When under load lower in the rpm range before I am about to down shift it does smoke some but it is more of a light grey and is not a super thick cloud.
I am sorry I do not have specific information on the grade of the hill but it was fairly steep. I definitely feel like the truck shouldn’t have needed to go all the way to low range second gear to climb it. I would get and post a picture of the hill but pictures are terrible at showing elevation change at least with my photography skill level.

when climbing hills I usually down shift when I hit about 1500 rpm because I feel like that is as low as I want to lug it at full throttle.Do you guys down shift at the same rpm or do you shift at a higher or lower rpm.



I will say after 3 loads of rock this week I don’t feel all that excited to do much more shoveling. I think 3 or 4 more loads will finish the job so excited or not it still needs done.

 

[davidb56]

Ive only been in low range to test it in my truck. You should be able to pull a steep road in 1/H. I'd get a pyrometer before messing with the fuel even though you're no turbo.

 

[18operator]

When I'm downshifting up a hill, my eyes are on the pyrometer. Anything close to 1100 degrees warrants a downshift. Last thing anyone wants to do is lose a motor. But how your truck handled on the hills to me seems about on par. 10k is the end of the chart for this truck.

 

[frank8003]

Is not the torque peak sweet spot at 1800rpm?
Double clutch that puppy and keep it near there.

 

[frank8003]

Torque vs BHP vs fuel vs smoke


No lugging duh engine Please.
No reeving high the engine Please

 

[frank8003]

Turbo or no turbo a diesel needs air to run

 

[dmetalmiki]

Absolutely spot on, that truck of yours.
With that load and the steep hill you are asking quite a lot of it.
Each vehicle has a natural 'sweet spot (RPM), Know YOUR Truck, Find it , stick to it.
Laden, or unladen.
Laden (towing), I keep my M62 wrecker at 1800/2000 rpm, Up hills down dales!
I USE the gears (And Range) to suit.
And as I always say, Wassa rush?

 

[cattlerepairman]

V8sarefun, I can tell you that I have driven my truck with the standard LDT-465 and it was not, by any stretch of the imagination, quick on a hill. Having said that, I did not have to tackle the hills (4-5%) in low range. 2nd gear high seems where it's at.

While I have not driven an LD like yours, I have driven other naturally aspirated medium duty dump trucks and, yes, they will get you wherever you want to go, in their own time.

These trucks hail from a time when it was accepted and understood that a large, heavy vehicle will be slow when getting going, then mostly going slowly and will be stopping eventually after brakes have been applied.
Most of this has been lost in today's high hp environment where even a dump truck boasts 400hp plus. You have a quarter of that, if the moon is in the right quadrant. Modern dumps have large surface drum brakes or even disc brakes that slam on without mercy and are ABS controlled. You fly into the windshield when you stomp the pedal to the floor.

Having said that, it needs air (air filter is new, or clean, or cleaned out?) and fuel. The latter can be turned up; in your case the limit is how much smoke you are willing to deal with, for a very modest uumph increase.

I brought several 5ton loads of crushed stone home for the driveway; at least I could push the loads off with a rake and did not have to shovel. My back thanked me.
When I jackhammered the concrete front steps I had a bobcat to load myself with the concrete chunks, but on the dump site I had to push and shove and shovel everything by hand. So much so that another driver came over and asked "are you on a weight loss scheme or just having fun?"

There are days where I so much wish my Deuce was a dumping Deuce!! I have not gotten myself to doing that conversion. For one, I just can't cut the frame rails shorter and I do not want to lose the bumperettes. Maybe gringeltaube's mod....

 

[Dipstick]

Cattlerepairman you hit the nail squarely on the head when you said these trucks hail from a different time. I remember semis doing 15 mph or less up a long grade when I was a kid. Some of those had 5 x 4 transmissions too. One thing I remember reading from the Army's Deuce drivers manual was to keep the rpm at 1,700 or higher when loaded. Also , I remember reading somewhere, that the turbo on an LDT was only meant to satisfy the EPA's smoke complaint and wasn't meant to add horsepower. I'm not surprised that cattle don't read. And I guess sign language is out of the question, but it's too bad they never learned to talk like Mr. Ed.

 

[frank8003]

Truck was meant to take many and pull all the ammo across most anything in a field, plowed or not. What it is you want anyhow. Truck does what it was built to do.
Study post #5.
You CAN get lots more power pulling than that, it all costs big bucks.
Double clutch Her and use the transfer case and remain at torque peak.
We got time and no money. Anyhow, fuel is zero to cheap. Enjoy

 

[cattlerepairman]

Heavy duty truck diesels today make (roughly) 100 ft.lbs of torque per liter displacement. That is why one sees so many 10 liter engines - to get the 1000 ft.lbs it takes to move a big rig through the mountains at a good clip.
The LDS465 makes a paltry 440 ft.lbs out of 7.8 liters, so only about 56 lbs.ft. per liter. Even a size-comparable DT466e shakes around 800 ft. lbs out of the 7.6 liters displacement.

Your LD probably has about 300 ft.lbs of torque when in a good mood. It will need a significantly lower gear to wrestle the load up the grade. In addition, it makes that "power" at a low 1400 rpm. So, when you combine a bit less torque with lower rpm and a lower gear, the result is....slow.

Have a water bottle and sandwich ready to pass the time But, the engine will run at that load and those rpm forever and ever and ever, until you get there. It doesn't produce the gobs of heat the high-strung diesels need to disperse with huge rads, it will chug up the grade and not overheat.

At the same load, the LDT is marginally quicker, the LDS of course blows them all away, especially the one under my hood! Maybe I am exaggerating.

 

[V8srfun]

One day I am going to add a turbo to my truck but I may end up trying a more modern turbo with a wastegate and see if I can achieve lds like torque.

 

[Dipstick]

I once read an article suggesting that you can install the turbo, injectors, and injection pump from an LDS engine and gain about 15% more horsepower and torque. I think LDT engines are somewhat horsepower limited by their piston and combustion chamber design. When my truck starts dogging down on a hill, I'm double clutching at 1,700 and dropping a gear. Sometimes you just have to hug the right lane and put the four ways on. Occasionally, I'll pull off the road on a two lane and let faster traffic go by. I find that my truck likes to run at 2,000 rpm and, that in 5th gear the mere thought of a hill causes him to slow down, and I have a great running engine.