Diesel question

[oldpilgrim]

I find that for my needs (so far), I don't need the power or speed of my tractor running at 2k+ rpms. Max hp is at 2400 rpms.

Today I was out back cleaning up my woods and I had it going at 12-1500 rpms and it was providing as much hp and speed as I needed. I ran it about 3 hours that way, when my brother stopped by and told me I should run it faster as it might hurt the engine by running it so slowly. I can see running it faster if I'm digging/moving sand rocks etc, where it's needed.

Is there any truth to that? Do I need to run it faster, waste fuel, and damage my ears when I don't actually need more speed/HP?

 

[murphy1244]

I find that for my needs (so far), I don't need the power or speed of my tractor running at 2k+ rpms. Max hp is at 2400 rpms.

Today I was out back cleaning up my woods and I had it going at 12-1500 rpms and it was providing as much hp and speed as I needed. I ran it about 3 hours that way, when my brother stopped by and told me I should run it faster as it might hurt the engine by running it so slowly. I can see running it faster if I'm digging/moving sand rocks etc, where it's needed.

Is there any truth to that? Do I need to run it faster, waste fuel, and damage my ears when I don't actually need more speed/HP?

I don't run lower than 1800 when doing work if for anything to keep the oil pressure up.

 

[newbury]

There had been a lot of discussion on this on the TDI forum. For the newer "small" diesel engines they ended up recommending occasional "drive it like you stole it" to seat the rings for the first 10,000 miles at least.

I would think you should at least get it up to 2,000 rpms for a few minutes an hour.

 

[HEC]

I bought a new tractor several years ago and it kept burning a little oil . I was doing the same thing you are doing and the rings never got seated in . I took it and worked it hard at higher rpms and the rings seated and no more burning oil . These newer engines may be much different but I would work it once in awhile just to make sure. My dealer said to run it like you stole it but the manual says not too with the new B2650 , so who are you to believe . I am doing both so hopefully things will work out okay. My book states do not operate tractor at full speed for the first 50 hrs.

 

[Raspy]

I don't see any need to run it at full RPM all the time. That is ridiculous. Just don't lug it excessively.

Just like your truck. Do you run that at full RPM all the time? Of course not. if anything, tractor engines are made to work harder than automotive engines and can take being run at a leisurely pace with moderate loads. If you see it smoking, drop a gear and run the engine faster.

I don't run the backhoe at full RPM unless I want faster bucket movements, I don't scrape the road at full throttle either. No need to and it sounds much better at a slower pace. But if I'm pulling a very heavy load I'll ask it for all it's got and rev it to red line. That won't hurt it a bit either.

My New Holland, with over 1000 hours on it, runs like new.

It's really irritating when someone recommends that I "run it like I stole it". That is a really thoughtless term that says more about who said it than how to use equipment. Running at full RPM is fine and it's not running it like you stole it. I like my tractor, I paid for it and I'm responsible for it.

 

[DarkBlack]

I don't run lower than 1800 when doing work if for anything to keep the oil pressure up.

You should hit the bypass oil pressure at a much lower rpm than 1800.

 

[Gary Fowler]

I worked my tractor as hard as I could varying the RPM from idle to 2200 rpm (2500 is max rpm) as per the OEM break in procedure. It didn't use a drop of oil to the first 50 hour change and doesn't use any now either. After the break-in period I use the RPM I need to do the job but rarely do I need more than 1500 to pull anything I need. It will spin all 4 tires in M 3 at 1200 RPM and not lug the engine so why would I rev it to 2500. I mostly mow with it in 750 RPM speed (it has a 3 speed gear box) and engine at 1500-1550 so it turns the PTO at approximately 540. If I need more power, I drop it back to 540 speed and run it at or near 2150 which is the PTO speed but never faster.
As long as you aren't lugging the engine, running slower RPM will not hurt it to run for hours at anything above about 1200 RPM, if the engine is slightly loaded but not lugging, so much the better.

If you have to run at 1800 RPM to keep up the oil pressure, you better look at replacing your oil pump. It should produce nearly full oil pressure at idle.

 

[newbury]

I worked my tractor as hard as I could varying the RPM from idle to 2200 rpm (2500 is max rpm) as per the OEM break in procedure. <snip>

Which OEM and what year? 2009 Kubota? 2010 LS?

/edit - my 98 M4700 says do not operate at full speed for the first 50 hours.
On my TDI I did about what you did, occasional full speed to set the rings.

 

[PoorPlowboy]

My Kubota 7040 manual says to not operate at full RPM for first 50 hours. It uses about a half a quart of oil per 10 hours even up until now at 86 hours. I've gradually been working it harder and harder trying to seat the rings. I'm going to work the snot out of it for about 12 hours straight this weekend with an 8ft bushhog and see if oil consumption improves.

 

[SPYDERLK]

My Kubota 7040 manual says to not operate at full RPM for first 50 hours. It uses about a half a quart of oil per 10 hours even up until now at 86 hours. I've gradually been working it harder and harder trying to seat the rings. I'm going to work the snot out of it for about 12 hours straight this weekend with an 8ft bushhog and see if oil consumption improves.

Ill be interested in the result. You are still using dino oil right?

 

[KennyG]

My Kubota 7040 manual says to not operate at full RPM for first 50 hours. It uses about a half a quart of oil per 10 hours even up until now at 86 hours. I've gradually been working it harder and harder trying to seat the rings. I'm going to work the snot out of it for about 12 hours straight this weekend with an 8ft bushhog and see if oil consumption improves.

Also interested in the result. This would worry me a lot. I haven't seen any oil usage during break-in on either gas or diesel engines in the last 20 years or so. My impression is that manufacturing is so much better now that you don't have to be too worried during break-in.

 

[dieselcrawler]

I ran my 3005 easy for the first 3-4 hours then hit the field with the brush hog a full throttle. Doesn't use any oil, up to 113 hours now. I varry the throttle according to usage needs, mid-throttle for light loader work and box blade, brush hog takes all its got at wide open.

 

[PoorPlowboy]

Ill be interested in the result. You are still using dino oil right?

Yes. Kubota branded, specifically. I decided to use OEM oil until consumption disappears so there is no arguing if I have to press the issue. I have a good dealer that is aware of my situation and will make sure it's taken care of before the warranty expires.

 

[Arc weld]

Diesels are made to work. Some diesels will slobber or even get glazed up from continual low RPM. When working you don't need to be full throttle but there's a reason PTO speed is usually obtained at 3/4 or better throttle. If you want to putz around, get a gas tractor. Diesels are most efficient at higher throttle.

 

[brown40]

I think some of the concern is related to the torque curve of your particular unit. Run it just at peak torque RPM and the motor immediately gets "weaker" when the engine gets bogged by the attachment/duty. Run above the peak of the curve and the motor gets "stronger" as it gets pulled to the peak; run below the peak and the less than 100% motor weakens faster.
If you have a good sense of the task at hand and know nothing is going to try and drag back the rpms, there's no reason not to run lower, but for unknown contingencies, the motor having greater resources when the challenge is presented protects it from lugging. I try to keep at least 200-400 rpm above the peak (1750 for the yanmar) to have extra waiting if it's needed when I'm unsure. For PTO I run within 80-85% PTO speed at least so the attachment has more momentum working for it, even if the task could be done at 60%.
The beauty of the diesel is that they're typically rated for continuous PTO speed operation (usually at lower rpm's than gassers) without undue strain, heat, etc. creating problems... only more noise & fuel consumption. If you aren't lugging it, you aren't hurting it.

 

[fishheadbob]

It all depends. I rarely run the 50 hp anywhere near PTO speed unless I'm really needing full hp like when pulling a baler and full kicker wagon. Skidding too many logs, maybe. Mowing, snow plowing, running the woodsplitter, backfilling, never; more like 1000 rpm.I've had it for maybe 18 trouble free years. BTW, I'm half deaf anyway.
The little Deere has far less lugging power and needs to run in a higher rpm range to avoid bogging out.
I had a partner who loved to run in 2nd gear at 2000 rpm to travel from here to there; he had a strong aversion to doing the same thing in 8th gear at 900 rpm. Drove me nuts.
The manufacturers used to have a slogan I took to heart "Gear up and throttle down."

 

[Gary Fowler]

Which OEM and what year? 2009 Kubota? 2010 LS? /edit - my 98 M4700 says do not operate at full speed for the first 50 hours.
On my TDI I did about what you did, occasional full speed to set the rings.

THE LS, I bought new, the Kubota had 60 hours on it when I bought it and was already broken in. You may note that I said up to 2200 which is 300 less RPM than full throttle

 

[Gary Fowler]

My Kubota 7040 manual says to not operate at full RPM for first 50 hours. It uses about a half a quart of oil per 10 hours even up until now at 86 hours. I've gradually been working it harder and harder trying to seat the rings. I'm going to work the snot out of it for about 12 hours straight this weekend with an 8ft bushhog and see if oil consumption improves.

I would say that you babied it too much during break in period. It needs some hard work, not necessarily at full throttle but something to put some back force on the pistons for the rings to wear in tight. They might still seat if you load the engine heavy and then vary the throttle up and down from say near full throttle to about half and then back to full. Do this up and down at about 3-5 minute intervals for at least an hour, run it at PTO speed for an hour then do the variable speed again. If at the end of the day the rings haven't seated, they aren't going to.

Your oil consumption is almost typical of tractors from 40 years ago. Most diesel tractors of that era would use a quart or two per day when heavily loaded as with ground engaging activities that put the load at max.

 

[Topher265]

Running diesels at low throttle for long periods can allow carbon buildup. To avoid that, periodically run the engine harder at higher rpms.

 

[tman1020]

My manual states to run at least at 2200 rpm's but this is to allow the hydrostat to develop ample power. I still only run about 1800 RPMs for most tasks.