Break in period

hagrid

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I just wonder—in your BX23, for instance, how far below max is the rated working speed in your experience?
My teensy little 898cc engine needs to make 3200 rippums for either PTO output shaft. The pointe at which all of my engine's speed becomes mine is 3800 rippums.

My personal take on industry break-in periods is that they are slanted more towards the operator becoming familiar with the equipment rather than relying on heavy, predictable wear of components to get them into tolerance dimensionally.
 
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mcfarmall

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Kubota M5660SUHD, Farmall C
Sep 11, 2013
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Thanks, mcfarmall. So in your M series, how many rpms above the tractor's rated rpms is pegged out?
Just off the top of my head, about aother 400 or so...approximately 2850 rippums (thanks Hagrid! always thought it but never said it!).
 
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Mossy dell

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B2601 (2021) JD970 (1998) B2100 (1991) B6100E (1988)
Jul 20, 2020
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Thanks, GeoHorn. It sounds like my 2,800 red area will be pretty close to full speed. I am going to honor the "no full throttle" at least during break-in. But I bet it makes no difference good or bad to the engine. Does make me wonder why the manual is so conservative. Especially if the range between my tractor's 2,800 and full throttle is not very wide.
 

lynnmor

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B2601-1
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It doesn't matter if cars, tractors or trucks are discussed, this break-in subject always pops up. An engine and drive train is made up from various metals and plastics and anything made by man is not perfect. The parts need time to conform to each other till the surfaces are better mated. The juvenile sayings like "run it like you stole it" is just one example of this nonsense. Generally speaking, piston rings like speed to polish the cylinder walls and the entire ring wears to conform. Now bearings can be damaged if they are too tight or too irregular, so they are best treated carefully. Heavy loads put on an engine will cause high pressures in the cylinder and on the bearings, so the system shouldn't be worked hard early on.

Since we are discussing slow turning diesel engines, in my opinion the RPM is not much of a problem, but heavy loads might be. A diesel has full compression pressures all the time since there is no throttle plate in most. I would simply let the engine run freely and not subject it to things like heavy weed cutting or plowing that makes the engine pull hard. For example, if you have high weeds and the job has to be done, just take a partial cut at a speed that doesn't labor the engine.
 
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Mossy dell

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B2601 (2021) JD970 (1998) B2100 (1991) B6100E (1988)
Jul 20, 2020
274
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sw VA
My teensy little 898cc engine needs to make 3200 rippums for either PTO output shaft. The pointe at which all of my engine's speed becomes mine is 3800 rippums.

My personal take on industry break-in periods is that they are slanted more towards the operator becoming familiar with the equipment rather than relying on heavy, predictable wear of components to get them into tolerance dimensionally.
Thanks so much, Hagrid. I guess the smaller the tractor the more rpms needed for 540 rpm and working operation. Until the tractor tops out . . . I bet mine tops out before 3,800 if its working rpm is advised as 2,800. Basic stuff. But I have been away from tractors for 12 years and forgot a lot of what little I knew. Plus they were gear and I knew how to run them. Or knew, at least, how I DID run them.
 
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Mossy dell

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B2601 (2021) JD970 (1998) B2100 (1991) B6100E (1988)
Jul 20, 2020
274
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sw VA
It doesn't matter if cars, tractors or trucks are discussed, this break-in subject always pops up. An engine and drive train is made up from various metals and plastics and anything made by man is not perfect. The parts need time to conform to each other till the surfaces are better mated. The juvenile sayings like "run it like you stole it" is just one example of this nonsense. Generally speaking, piston rings like speed to polish the cylinder walls and the entire ring wears to conform. Now bearings can be damaged if they are too tight or too irregular, so they are best treated carefully. Heavy loads put on an engine will cause high pressures in the cylinder and on the bearings, so the system shouldn't be worked hard early on.

Since we are discussing slow turning diesel engines, in my opinion the RPM is not much of a problem, but heavy loads might be. A diesel has full compression pressures all the time since there is no throttle plate in most. I would simply let the engine run freely and not subject it to things like heavy weed cutting or plowing that makes the engine pull hard. For example, if you have high weeds and the job has to be done, just take a partial cut at a speed that doesn't labor the engine.
Great advice. Get this break-in story. When my wife got a new Subaru in 2014, the range selector was different. All the way down is Drive, but pulled toward you from Drive it is Low. Which felt right to her, dragging the shifter into that notch. She drove it in Low for hundreds or maybe more miles, including on the interstate. I remember commenting when I rode with her once that the engine sounded loud. And I caught the problem a while later when it went through a quart of oil.

Here's the thing. Seven years later it runs fine and uses no oil. I'd never recommend what we did, obviously I am prone to baby engines, and clearly it worked the engine brutally on the highway. We keep our cars a long time and may find there's a price farther down the road for a dumb mistake. So far, nothing though.
 
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GeoHorn

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Not the same thing, but similar.... with new piston aircraft engines (which also run relatively slow RPMs in a similar range of 2500-3500 RPM) we are told by mfr’s to stay at low altitudes and run high power settings. This is supposed to enable high cylinder pressures to quickly seat rings hard against cylinder-walls and prevent cylinder-wall “glazing”. The low altitude also equates to high barometric pressures (dense molecularity) and promotes good cooling of the air-cooled engines finned cylinders.
Warnings are issued that “babying” the new engine can lead to improper ring-to-cylinder break-in and resulting in high oil consumption for the life of that engine (unless an expensive corrective action is taken of replacing cylinders and rings again.)
How might this relate to tractor diesels? Diesels already have high cylinder pressures which facilitates ring break-in at normal operating RPMs... but long periods of low speed/idling would not be good for ring-seating... and heavy workloads will stress the drivetrain before bearings and gears and pumps have broken-in.
I’m not trying to come across as an “expert” on these engines.... I’m only thinking and conversing “out-loud” in an effort to help understand the controversy.
It’s your tractor... and I doubt you’re going to hurt it anyway and if you’re like the typical hobby-tractor-owner, you’ll only put a hundred hours a year or so on it.... so I also doubt you’ll outlive your tractor so how you break it in is unlikely to destroy it.
So, go enjoy it and as the song says “Be happy.... Don’t worry”... (If you really really REALLY want to be extra nice to it... do an (extra) early oil and filter change and it’ll love you for it.)
 
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Mossy dell

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B2601 (2021) JD970 (1998) B2100 (1991) B6100E (1988)
Jul 20, 2020
274
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sw VA
To wrap this up with my bottom line takeaway, I bumped my speed up yesterday. I did stay in the red operating area. Based on the wisdom in this thread and my former experience, I don't think speed per se is much of an issue. I think it's load. I wish instead of warning about never running at full speed, in break-in and even later, the manual said:

Avoid sustained heavy loads, such as cutting heavy vegetation, in the first 50 hours. Take narrower cuts/smaller loads if heavy work is necessary.

I'd wager this is actually the issue the nervous manual writer tried to warn of.
 
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Nicfin36

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L2501 HST, BH77 Backhoe, SSQA Loader ZD1011 Mower
Jun 19, 2019
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I also doubt you’ll outlive your tractor so how you break it in is unlikely to destroy it.
So, go enjoy it and as the song says “Be happy.... Don’t worry”... (If you really really REALLY want to be extra nice to it... do an (extra) early oil and filter change and it’ll love you for it.)
This was MY biggest takeaway from the thread. The older I get, the less I worry about many things. :ROFLMAO:
 
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jimh406

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Kubota L2501 with R4 tires
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I think the L2501 is an anomaly. That is, there seems to be a lot of evidence that it’s detuned. One user both upped the RPMs and also turbo’d his. Mine runs right at 2200 for PTO speed, but max RPM is 2350. Personally, I don’t think that’s very much difference. I’ve run mine at max RPM for a while pulling a lot of gravel for the neighborhood road the first pass or so. Frankly, it didn’t seem to care and temps never increased at all compared to 2200. YMMV.
 
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PaulL

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B2601
Jul 17, 2017
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My B2601 max rpm is the same as the 540 rpm mark. To mow I run full throttle. No idea how I'd break it in at less than full speed unless I were to mow at lower rpm, which seems like a bad idea. It sounded like weasel words to me so I ignored it. Tractor hasn't complained.
 
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muddhogg

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Kubota L2501DT, Ford 3910
May 20, 2018
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I have never broken in a tractor, vehicle, atv, utv, etc… I buy it, then I use it to do what I need.
 
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