lugging the engine

BruceW · Aug 24, 2001

I have read items on TBN in the past that lead me to beleive that loading the tractor down to a near stall or stall is a "bad thing". I have been digging with my loader and in the process put a big load on the engine dropping rpms and once in awhile ( 2 or 3 times in an entire days work) it will actuall stall.

Is this causing damage? If so at what point of dropping engine rpms does damage occur or is it only when a hard stall occurs? What type of damage could it be causing?

thanks

bruce

MChalkley · Aug 24, 2001

Nobody else seems to want this one, so I'll take a stab at it. You're not going to find a specific textbook definition, and non-specific definitions of this sort of thing tend to be non-useful, so I'll offer a relatively specific (or adaptable, at least) working definition. (It may not appease an engineer, but said engineer is free to post his or her own definition, if they like. /w3tcompact/icons/wink.gif)

Lugging an engine usually refers to running an engine at a low rpm and getting more work out of it than you should be for that rpm by using heavy throttle. A primary indication is black smoke (at the prerequisite low rpm). What's a low rpm, you ask? That depends on the engine, but anything under half-way between idle and the rated maximum torque rpm is a good start. For example, if idle speed is 900 rpm and peak torque is rated at 1800 rpm, anything loading under 1350 rpm (or so, obviously) that produces heavy black smoke would constitute lugging.

Another pertinent factor is the duration of the load. A sudden high load situation that results in stalling the engine does not constitute lugging. While it's not the most gentle of things to do to an engine, it happens all the time, and never seems to destroy them, at least not quickly. In order to truly constitute lugging the condition has to be of longer duration than what you're describing.

MarkC

Bird · Aug 24, 2001

Thanks, Mark, well said! I hadn't been able to decide whether I wanted to wade into that or not. You said it better than I could.

Bird

MChalkley · Aug 24, 2001

Thanks, Bird! "Better" is probably debatable, but I'll bet I said it in more words than you would have! /w3tcompact/icons/laugh.gif

MarkC

glennmac · Aug 24, 2001

So if you're on a date and she says no once, she's stalling; but if she say's no ten times, she's lugging?

MChalkley · Aug 24, 2001

No, I think you're talking about the difference between stalling and stalled... /w3tcompact/icons/smile.gif

MarkC

treeboone · Aug 24, 2001

I think you will find it will stall less as you get more hours on it. You will develop a second sense and intuitively know what the tractor is capable of. (Zen and the art of tractoring...) I run the 4610 at 1800 RPM most of the time and use low range on the HST. I might run up to 2200 when bushhogging or shuttling in midrange. I get more control by the amount of hydrostat feed than by engine speed. If I am having problems with the tractor, it is often because I am trying to go too fast at some task. If I take a break and relax, I can come back to work and try to relax and use more "finese" and it seems to work better. In other words, the nut behind the wheel gets too tight sometimes.

MChalkley · Aug 24, 2001

treeboone - Agreed. I stalled my L4310HST out more times in the first 10 hours of use than I have in the last 300. And I usually run it at around 1800 rpm, too, unless I need the speed, PTO rpm, or extra pressure for really heavy work.

MarkC

bulky · Aug 24, 2001

Bruce I drive a truck for a living and one thing i learned is that when you lug a diesel engine especally to a stalling point you can push the piston liner into the crankcase. I dont know if these engines have liners or not.