Lugging diesels = bad or newfangled myth?

Cacinok · Oct 6, 2004

( 2. The flip side of this is I think Kioti's are underpowered across the board thus my fears and subconsciously (until now) the reason I have asked all the questions that I have about engine speeds and longevity in this thread and in others. I made a conscious decision that the engine size was something I could live with and just take smaller bites as long as the frame and everything else was built for durability. Obviously this was not a big enough factor for me to over ride item #1 thus my choice in tractors.)

Why do you believe that Kiotis are underpowered? Does their 20hp model only have 10hp? Please explain.

( Maybe I've come full circle and am coming to terms with my decision, but I wish they would design them so that in standard work the engines were only pulling 60% or so of rated capacity. I don't like the fact that the engines need to be running near full tilt to do what they were designed to do. Power reserve should be designed in.

NO tractor had a model that met that wish for me. This goes right back to that new fangled way of thinking... todays designs not just for beef.. but for power, seem to be to design something so that it performs its intended role right on the point of failure (almost overloaded structural design, or almost underpowered powerplant). That whole way of thinking eludes me. Design something so that it is working at 50% of capacity during its normal duty cycle and it will last FAR more than twice as long. )

It seems to me that if you want a tractor that, during standard work, only pulls at 60% of peak power you should buy a tractor with 40% more power than you need. Or use implements that are a size or two smaller (too much math for me to figure out what 40% smaller implements would be) than what is recommended for the horsepower of your tractor.

I don't think that today things are designed to run at the max potential of the device, especially not at overload. If they were, then you would not be able to spend a few dollars and get a performance boost (e.g., new chip for a computer controlled vehicle) and still have a long lasting engine.

I think the issue may not be to lug or not to lug, but to buy bigger or not to buy bigger.

Clint.

slowrev · Oct 6, 2004

Not singling out any particular poster with this reply.

I have always been jumped on about lugging the engines in everything I have owned. To date I have never had any bearing problems in any engine yet. Everyone says I lug my old Subaru, Well 200k on it and no rod knocks or anything yet, still has origional clutch too. And I admit I do lug it. So I will just keep on lugging. Why do you think my handle is Slowrev ? Not from being a retarded minister /forums/images/graemlins/smile.gif

I just agree to disagree and keep on doing it my way.

Ben

rockyridgefarm · Oct 7, 2004

I DID notice your handle and wondered when you come out with it!

slowrev · Oct 7, 2004

Friends sort of gave it to me years ago. Had the handle all the time on here, was platinum before the great ID crash and just re-established it and started over.

Ben

LBrown59 · Oct 15, 2005

Why do you believe that Kiotis are underpowered?
1*Does their 20hp model only have 10hp? Please explain. 
=============
1*I don't think this is what he means.

I believe he means powering something with 10 hp when the power plant should have 20 hp.
At least that's what under powered means to me.

Bob_Young · Oct 15, 2005

Slowrev, you make a good point; one that was made to me some time ago. My Dad always lugged all his engines, auto, truck and tractor. Let the RPM drop as low as possible before shifting down. Taught my Mom to drive the same way.

When I thought I had learned something about cars and engines, I started getting on him about it. He never paid any attention to me except to yell about wasting fuel if I didn't shift UP ASAP.

After awhile I noticed he never had any engine trouble with any of his vehicles/equipment. They'd be total rust buckets with the body falling off, but the engine would run like new. That's when I decided that the acquired wisdom about lugging engines was so much hooey. Now I pick the lowest RPM that will comfortably get the job done and shift down only when it starts to buck.

I'm constantly amazed at how comfortably and capably my L4300 toils away at only 1200-1300 RPM. And, though I've never equalled the 26mpg Dad would routinely get with the Cummins Dodge, I've gotten 24mpg several times and 25mpg once. /forums/images/graemlins/laugh.gif
FWIW
Bob

Slamfire · Oct 15, 2005

I've got an old (1975) Mitsubishi, gear tractor. The horsepower is rated at 2300 rpm. The torque seems to peak at 1800, and it pulls real well at that speed. So I run all the equipment at that speed, sometimes in a lower gear than is necessary. 1500 rpm is a lot quieter, so that's my transport speed. It will slow some on a couple of the hills on my drive and I step on the foot throttle before climbing and run the rpm up to 1800. I use 1000 rpm for a fast idle when I want to jockey equipment around with the hydraulics, and warm up. For a cool out idle I run it about 600, cause it sounds good at that speed, it'll ring some when cold at that setting but not warmed up. I'm an official old timer, gettin' medicare, and don't much care for HST and all that stuff, but I can see the advantage of shuttle shifters. My Dad operated heavy equipment for a livin', and he never ran any motor above the torque peak, said it was a waste of fuel. That's always been good enough for me, but what do I know? /forums/images/graemlins/crazy.gif

marks · Oct 16, 2005

When an engine is being lugged, the bearing pressure is at its hightest and the oil pressure is at its lowest.

TMcD_in_MI · Oct 16, 2005

( When an engine is being lugged, the bearing pressure is at its hightest and the oil pressure is at its lowest. )

Since oil pressure is a function of RPM, I can definitely understand why it would go lower as an engine begins to lug. But, could someone please explain why bearing pressure would go up? And does it go up by a significant amount?

Tom

HGM · Oct 16, 2005

centrifical force.......

At higher opperating speed the crank and pistons are moving at the same speed(can keep up with eachother). When you lugg your engine, the crank is being held back and the timing is off. The "BANG" happens at the wrong time excerting more blunt force on the bearing instead of a push in the rotation.

What happens when you're towing a trailer and hit a bump? The trailer jerks and bangs on the hitch. Not a good thing, but if it happens regularly and violently, you change your speed.. Right?

I cant explain, why some guys have not had issues with their engines because they like to lugg them. However, I would be willing to bet that their engines have more wear than someone who runs their engine at the correct speed.

From what I have read seems that some have a different interpretation of lugging. A slow running engine that is not puffing black smoke and loosing RPM is not lugging. If you are loading your engine an see black smoke and loose RPM you are doing damage to your engine. By the way, if youre doing it to conserve fuel, you're really wasting more. Keep your engine in the powerband for the job your doing and you will get optimum fuel economy,performance, and longevity.