Diesel Engine Break-In

When I bought my JD 5055d with the 2.9L - 3 cylinder engine I made it a point to work the engine during the first 100 hrs. Also had the dealer give it a dyno workout before delivery.

Friend of mine just bought a new Deere and he worked it hard for about 5 hrs and feels good to go.

My question is - tell me about breaking-in a Diesel engine, new or say for a classic, like my MF50 or an IH 856 or a JD 4020 when the engine has been rebuilt? Are the rings basically seated instantly upon hard use - what are you getting over the first 100 hrs from the new or rebuilt engine and the break-in oil in it?

Is my buddy's tractor good to go - normal operation through the remainder of the break-in period or more heavy loads, like I did with my JD to the 100 hr mark and then a normal oil and filter change?

Thanks!
Bill

Can't tell you for sure, but all the pickup forums harp about not working an engine too hard until broke in. As far as tractors are concerned, I would worry more about getting a rebuilt engine seated in than a new one. Today's manufacturing tolerances are tight and consistent.

I would not work a new engine max HP for a long time. A long time ago I rebuilt a M5 Moline diesel. I had the block bored just shy of mininums. Started it and was fine. Put on dyno and at 50 HP would get tight and pull down. We ran it off and on for a week. Just short bursts of full power. Finally it would pull 7? Some HP for 5 minutes or so. That tractor ran at least 30 yrs. But never put one together that tight again.

You had the ring gap too tight.

We were always told at Vo-Tech not to let an engine idle after an overhaul and work them such as grind feed or haul manure. Varying the load and engine speed at least 1/2 or 3/4 throttle helps. I overhauled a ZA MM in Vo-Tech and when I broke it in I took it out in the oats stubble field with the JD straight disc. I V'd the disc slightly and went in a higher gear for a bit, then V'd it a little more and went in a lower gear. That was in 1986, never used any oil to speak of, even when plowing with it.

FWIW, my observation.
At my last job, they got in new trucks from the factory delivered by drive away-saddle mount. That means drive one, tow two or three, gross weight about 60-80,000. Hitch em up & hit the highway.
When put into service, hitch up a load & go. They got around 200 units a year, rotate out at around 500,000 miles, never saw any with engine failures.
Job before that with a major cross country bus line. New units driven from factory at highway speeds. They would get tired at about 800-900,000 miles. Do an in house rebuild, send out again.
Always liked to watch a new rebuild on test stand. Hook up temporary battery, fuel, radiator & muffler. Warm up about 15 minutes, check for leaks, & open it up. Head machinist would say "No parts bouncing off roof, must be a good one". Install engine, do final tuneup tweak, & put on ready line. First trip out would usually be Minneapolis to El Paso or Laredo round trip, stop long enough to slide in relief driver, top off fuel, & go.
In other words, ease into it untill water temp comes up to normal, than put it to work.

Willie

I know that's what they tell you, but dad took his 2001 Chevy 2500HD with a 6.0 and hitched it to his 30' fifth wheel and headed to Idaho from Michigan. It had 200 miles on it, got around 3 miles a gallon until he hit around 1200 miles! At that point it started increasing until he got a whopping 100% increase in mileage, and there it stayed! 6mpg while towing lol, got 13 empty one time. Dad said if it wouldn't hold up to that, he didn't want it. Held up just fine, he now has a Duramax.

Ross

I knew three people who bought Farmall 966's when they came out. They didn't work them hard until months/hours after they were new. The guy I worked for complained that the 966 used a lot more oil than the 806 he traded off did. I assume the 806 was using oil, is why he traded it off. The dealer took the 966 in and put it on the Dyno, covered up the radiator and worked the snot out of it at about 220 degrees for 24 hours and got the rings to seat. I heard that Chrome rings were new about then and they needed to work hard to get them to seat. I didn't work for him after that, so I don't know the how the tractor was long term.

I have had the best luck with putting them to work hard, no babying.

Maybe you should mention that to the drag racing guys that put all new stuff in the engines, then run them for a total of 3 Mins. +/- and produce 10,00 hp.

Please, please, please, somebody explain "seating the rings" ! There is nothing to 'seat' them against or to. They are at the peak of performance when new, after that it is called wear.

This has nothing to do with break in, but when I used to work on equipment, I would always cringe when I would hear a mobile genset cold start in the winter and go full throttle as soon as they start. I believe one we had around the shop was a 350KW, a large one, you would swear it was going to pitch a rod when it full throttled cold.

Ross

Your John Deere operators manual states: "the engine is ready for normal operation". Avoid prolonged idling. There are 10 hr, 50 hr and 100 hr service requirements. Like, change the oil and filter, add oil as needed, etc. In my case I took my brand new tractor out and did some heavy duty bush hogging because that was what needed to be done. If it had been plowing, disking, planting or whatever that needed to be done, that's what I would have done. That was 15 years ago. Still running like a champ. Just consult your operators manual. There is a treasure of information in there after you get past all of the liability stuff.

That scares me too, but I guess they offset the risk with the power outage.

Yeah, and how many miles do they last???

Ben

the rings are worn in to seat against the cyl. wall. when the plug ignites the fuel mixture on the compression stroke the rings are driven into the cyl. walls. when put on a load the rings are forced much harder into the cyl wall to wear them in to make a good seal. taking into consideration that the engine is at operating temperature when seating rings.

After I overhaul an engine it goes to the farm repair shop or a dealer that has time to dyno it. They both run them around 6-7 hours depending on when they can get to it in the morning and run it till quitting time. Their policy not mine, I'm fine with it. chris

i like to get the water temp up and then work the he$$ out of them. i have seen guys baby new ones and they tune out to be dogs

If you look at various engine mfg's suggestions, as well as the advice given below, you'll find what they all suggest will vary somewhat. This is going to happen based on a variety of factors, one being the makeup of the rings, as well as the material in the walls of the block/cylinder.

Personally when I build an engine I simply tell the customer that they need to "work" the machine when they get it home and not to let it idle a lot. Heck, idleing a engine too much, and/or not running it enough to get mup to operating temp for any length of time, rings seated or not, is just asking for problems.

Over the years I've seen a 4-71 Detroit in a crane that was wet stacking to the point when the machine was run hard, the exhaust system caught fire. Shoretly afterwards I was asked to rebuild the engine, after the airbbox drains started pouring oil. Once rebuilt I gave them the same advice to work the machine. In the job they were on that wasn't possible and it began to wet stack again. I can't remember what all we did on that machine, but between it being the middle of winter, and the limited jobs that could be done with the crane on that particular job site that would actually put it under a load, we had a heck of a time ever getting the rings to seat in that engine. (didn't want to use the trick below because of the blower)

Rebuilt one in a MF 1654 a number of years ago. This tractor is used in a specialized application and it's main job is powering a hydraulic pump to operate a conveyor system permanently attached to it, so it routinely runs at an idle. Once again, the advice to run it hard was given, and not followed. In that case, I had to put cardboard over the radiator to get it to full operating temp (middle of winter at the time). Once the temps came up, I removed the air filter and slowly fed a tablespoon of Bon-Ami powder into the intake. I let the engine continue to run about 3/4 throttle for another 30 minutes, then bumped it up to full throttle for a little longer. That was 10, or more, years ago and it's still running strong nearly every day, with no issues what so ever.

Dad used to see the same thing when buidling engines for the local A/C- F/A construction equipment dealer back in the 70's. He finally quit letting any machine leave until they had taken it out back and let it run, under a load, for a while, to seat the rings. Once they began doing that, he said they never had any comebacks, or complaints.

Ultimately, the main thing is get the engine to operating temp, and run it with a load for awhile when it's new. Even after it's broken in, don't idle it for long periods of time if you can help it, without that time being followed by a period of heavy work to insure everything heats up.

Just curious why would you want to dyno a tractor. Aint that just a little over board.

A freshly honed cylinder wall has "peaks and valleys" cut by the hone. The sharp points of the peaks are not strong enough to handle the pressure of the rings being pushed against them so the point breaks off.This happens again and again until the "peak" is broken enough to take the shape of a plateau. That plateau is wide enough to bear the load of the piston ring and now it is "broken in".

Thank you.

Thanks everyone! Great info on breaking-in a diesel engine - much appreciated.

Bill