Lugging diesels = bad or newfangled myth?

[kevinj]

Back in my days as truck mechanic and driver Cummins and Cat both said; if the engine will pick up rpm with the load applied then it is not lugging, at any rpm if it will not pick up the load (gain rpm) you were lugging the engine which meant drop a gear or two to reduce load. I have applied that logic for over thirty years to ALL engines and have never had a problem. What works for me may not work for you. /forums/images/graemlins/cool.gif

 

[To20Chris]

The sound of my 4cyl gas Ferguson is quite sweet, and while I really like my Kioti, I guess the sound of a 3cyl diesel is just never going to cut it for me! I transport at 1500RPM, and run the BB at 1800-2000RPM in up to 4th gear (low range). The only time I go over 2000 RPM is to get maximum lifting with the FEL, and then I'm at about 2500RPM. The ear protectors hang nicely on the joystick boot, where they're within easy reach - I'm wearing them whenever it's over 2000RPM. I sure do respect that diesel, but what a racket!

 

[beenthere]

KevinJ
That is how I handled/learned to do the 'lugging' bit too. Still do, and it makes sense, both gas and diesel engines.

 

[beenthere]

</font><font color="blue" class="small">( The HST does pull the engine way down when just putt-putting around to get from one place to another. I typically throttle down to around 1700-1800 RPM and then travel in high range with the peddle fully depressed. This will typically pull the engine down to around 1400-1500 RPM. This yields a laid back travel speed and pleasant sound (like old time tractors). Makes it fun to be out there on it. )</font>

getut
I wouldn't treat my engine that way. You may, as it is just my opinion. Seems that you are lugging both the engine and the HST system. But suit yourself. This is one reason the e-hydro was developed, to keep engine RPM up while moving within a gear range, by controlling the speed (forward travel).

 

[getut]

Ok beenthere, you've successfully got me going again.

It is not on purpose, but now that I look back on it, it seems like nearly every post I have made boils down to fears (some founded some not so much) of not enough power and how it will affect the longevity of my tractor.

1. I like the beef of the frame on the Kioti. It was probably THE deciding factor on my going with Kioti. As I said, I don't particular ly like over engineered items i.e. fancy alloys in a ladder frame. I like BEEF. This is purely a perception by me. I don't make any claims of it being fact, so I'm not bashing anyone elses decision. I just want my tractor to last a long, long time.

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.

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.

No wonder the old stuff lasts 40 years and we can't duplicate that this day and time.

<End soapbox rant>

 

[shvl73]

A lot of the newer tractors have more power & torque than the old machines. Compare your CK20 to an old Cub. If such a tractor were asked to do the things our modern machines are asked to do they might not have held up as well. Some of the members have done some amazing amounts of work with their sub-cut's.

 

[beenthere]

Sounds reasonable to me. /forums/images/graemlins/wink.gif

I usually set my 'gear' in mid-range, the RPM at 1200-1400 (not too wound up and comfortable to the ear) and set the cruise control. No load on the engine, sounds good, I move at a reasonable pace but not too fast, and enjoy the ride. I do most of my tractor work at or below this RPM throttle setting.

John Deere's apparent new line of CUT is an engine that operates at lower RPM's than the present line of Yanmar diesels. There have been some discussions of the higher torque values of the 3x20 series.

 

[cowboydoc]

<font color="green">In the community that I grew up in, it was nothing to see 20-40 year old tractors putting along at barely more than an idle pulling a trailer load of hay stacked 15' high and really lugging up the hills. </font>

They weren't designed for that and still aren't. The problem with the older tractors is that most of them were not synchro. Thus you had to stop and change gears. If you do that on a hill with a load your brakes probably won't hold and you would crash. On the older tractors you pretty much put it in the gear that you are going to get the most speed and still make it up the hill. Same with pulling a baler, plow, etc. On the hills you lose power fast, but if you stop you may not get going again. So you lug it up the hill and then get right back up to full operating speed. As long as the lug is temporary it doesn't cause much damage. But if you're going to go out and plow all day and lug the engine in too high of a gear you are going to cause excessive wear and heat.

As far as idling diesels that certainly is true not to idle one. All of the new trucks have an idle controller, and most semis. What this does is varies the idle so that the truck is never idling at the same speed. Idling at the same speed for hours will cause alot of damage.

And yes it is true that all of this is compounded double with a turbo.

 

[QueBota]

What Kevin said, if you can't accelerate in a given gear you are lugging the engine.

Extended idle time for a warm diesel engine is not good. Idling to warm up a cold engine is even worse. Cylinder wash down can occur and incomplete combustion can leave deposits on injector nozzles and valves. When you idle for extended periods exhaust gas/cylinder temps tend to fall below what is necessary for complete combustion.

If we have to idle our trucks for an extended period we idle up a bit and engage the exhaust brake.

Dave

 

[RonR]

So Dave,

If it's 20* out and I need to start my Bota, I use the glow plug for awhile, crank it and it fires.

Surely you don't mean for me to take off working with it at that temp. Wouldn't idle be better for a short period, rather than reving it up right away?

Curious.