Have we been doing it wrong? High rpm's bad when not needed?

[confederatemule]

I a simply telling how I do it. Right or wrong ??. My diesel engines have never give any trouble of any kind.

I have worked on and operated equipment, of one kind or another, with Diesel Engines since mid 1960s.

I bring them above idle only when I need more power. I do not run at any RPM higher than I need to get the job done. I also am careful not to lug the engine.

Course, I am the sort of person who does not care how anyone else does something. I do things the way that works best for me.

Mule

 

[LouNY]

A diesel engine will not generate very much heat in the exhaust unless it has a load on it. High rpm's with no load it has a tremendous amount of air being pushed through with very little fuel. Very little fuel= very little heat.
The more load the more heat it will also generate as it takes fuel to carry the load, more fuel = more heat. Moderate load will provide heat and minimal particulates, heavy loads will provide lots of heat also lots of particulates.
If you really want to watch that install a pyrometer in the exhaust and watch the temperatures as the loads vary.

As far as fuel dilution in cold weather idling it is quite common, especially with low rpm idling. As the engine will have a difficult time even getting to operating temps without a load. That is the main reason that we cover our radiator openings in cold weather. The warmup times are greatly reduced and the performance is greatly increased.

A dpf equipped engine will regen much better when at temp then when it is cold. Diesel pickups will demonstrate that quite easily if you have a monitor to watch the regens, cold weather the exhaust will lose so much heat that the system will dump extreme amounts of fuel into the exhaust to bring the temps up.

 

[RandyT]

Thank the Lord I don't have to worry about that regen <censored.>
However, my BX2660 manual says to keep my rpm's around 3100 or so when mowing the grass (regardless of engine load I assume as the manual doesn't say anything about that.) So, am I doing it wrong and possibly harming my little 3 banger (25 1/2 hp)?

I would say you are fine. I suspect the 3100 comes from maintaining speed for the pto not so much for the power. And I would also say that 1800-2000 would be sufficient to maintain proper oil flow to the hydro. Most of the stuff I work on recommends 1800-3600 input rpm to the pump.

 

[RB5]

Interesting. I run most of the time at 1500 RPMs unless I need more for pto or loader work. I have a Deere 4044M. The only time it has ever gone into regen was when I idled a little more than usual while getting off to move something or do work or when my father in law ran it and had no clue about the regen and newer emissions controls. I'm sure he ran it at low RPMs like the older tractors. When I got it back he told me it was sounding loud and he shut it off during regen. That regen took a while when I started it back up. I use lower gears if I need to move slower. I've had the tractor at least 6 or 7 years with no issues.

 

[RB5]

Let me check what the manual for my 1964 Ford 4000 says about this and I’ll get right back to ya’.

I hope yours is in better shape than my 1970 Ford 2000 gas tractor. At the end I spent more time repairing than using it every time I wanted to do something. The last time I tried to use it the tractor got stuck in gear. Parked it and it has not been moved since.

 

[Elviscaretaker]

It's interesting reading the issues others have and how they do things. I run my TC-30 at about 1800-2000 rpms for most things, no issues but mainly to keep it from bogging down. It's a tier 0 so no emissions crap on it. Now my Duetz (tier 4) I tend to run at an idle for loader work, moving hay etc. In the field in E mode for the pto about 1400-1600 rpm's(?). I'm pretty sure I can get away with 800 rpm's if it were not for the needed pto speed. Only time I crank it up is when I'm on the road and want to get there faster. At 500 plus hours I don't THINK I've had a regen on it. But it isn't noticeable on this one if it does nor does it tell you. Dealer just says run it full throttle to clean out the filter for about 30 minutes (did it once, got bored). Other than that I basically run it as needed with keeping the revs lower and it's only noisy when I have equipment attached to it. Then my hearing is shot so maybe it is noisy One of my riders has 35k hours on it with a 25hp kohler in it, never rebuilt and I beat the crap out of this one as my edge mower and trail mower. Full throttle all the time .... Just kept up on filter/oil changes is all. All in fun...

 

[jyoutz]

All I can say is, I'm sure glad I don't have to deal with any of that.

I will say the only time I see smoke (soot emanate from either of my M9 turbo charged pre 4 diesels) is a little puff on cold start and if I'm working them hard like a full bale chamber or mowing tall hay at a fairly high ground speed. Other than that I se no visible 'particulates', aka: soot and I'd assume your post 4 units exhibit the same characteristics except the particulates get captured in the DPF or in the case of higher power diesels, burned by the oxidation catalyst, aka: DEF.

I will never own a post 4 diesel, ever.

I can’t say that there’s anything to deal with. My regeneration events have all occurred when I was working, rotary cutting or grading the road. I just raise the throttle a bit and keep working. I see a bit of white smoke for 10-15 minutes and then it’s over.

 

[TractorNoob85]

I'm not so much concerned about the regen events as I am about the ash buildup that WILL occur over time. Hopefully, that crap is easy to clean out with water when the time comes.

 

[jyoutz]

I'm not so much concerned about the regen events as I am about the ash buildup that WILL occur over time. Hopefully, that crap is easy to clean out with water when the time comes.

The required minimum longevity for a tractor DPF is 3,000 hours, with many lasting twice as long. Unless you use your tractor for full time farming or other work, most compact and utility tractor owners will never experience a DPF failing.

 

[CloverKnollFarms]

Are there many DPF units past 3000 hours yet? I mean, utility tractors? Most folks use them 50 hours per year? And DPF has been on them for what, 10 years? Probably not many units past 3000 hours? Just browsing used tractor listings the past few years, most post DPF units are still under 1000- 2000 hours.

Which supports the idea that we don't use them enough to really expect an issue, except for ECM issues that some have.