Yes this is a controversial approach to breaking in an engine.
Beating on it... No. What your trying to achieve is seating the rings with good pressure by loading it for the first 100 or so miles. Lugging the engine on a steep mountain climb with a high load weight is perfect for this. But of course if you don't have a access to a mountain, then heavy acceleration without over revving would have to suffice.

Here is an interesting white paper on a break in of a Lycoming engine as per vwnate's statment.

__________________
1983 123.133 California
- GreaseCar Veg System

guess my reply was aimed specifically at - run it like you stole it -
that's a far cry from utilizing 70~75% of the engines power to seat the rings.
high rpm's seem to be contraindicated by all sources, on all engines during break in period. And one things for sure, If I steal a car, I'll be hitting the rev limiter, whether it's got one or not.
At least Newbie is in a pretty elite club - MB diesel drivers who have gotten speeding tickets.

Nubie :

You said the cam chain snapped as you were driving ~ had you adjusted the valves or had the rockerbox off and if so , did you look at the alignment marks
to ascertain the amount of chain stretch ? .

I'm just curious here .

TIA ,

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Hey Nubie, give me a heads up before you head East so I can blow out of town to the Orient before you get here. Don't worry, I'll leave you the paint (and a brush or roller). LOL.

BAck from the 1000 mile plus road trip from southern NM to about the middle of Colorado (Roswell to Buena Vista ultimately, Roswell to Antonito non-stop about 400 miles). It's too late to break her in easy - first 200 after Indy's tech drove her an unspecified amount of miles over a weekend were Santa Fe to Roswell - couldn't keep her pegged but every time I hit a hill I floored it and had her running at 85 mph steady for the duration. Had to be somewhat cautious on the recent road trip due to accumulating speeding tickets but it was largely road, significant portions at 75-80 mph. Got much better fuel mileage on the return (odo doesn't work but I had trip tik miles for driveway to destination) - 25 mpg versus almost 30 on the return. "Downhill" from Colorado back, but stretched out over 400 miles shouldn't have made THAT much difference.
One Major problem: She ran great, but didn't start twice. I had major, major charging system probs before the timing chain meltdown over a year ago with a common pattern: PO had replaced battery and alternator within six months of my acquisition and she wasn't driven much. I had first a battery problem and Sears replaced, and then an alternator problem which I had replaced. The pattern was that she started and ran fine for weeks while only driving around town. First long road trip came hard starts, and then jump-starts, and then battery failure. Replaced alternator again. Same situation repeated. I had six (yahoo) guys (mostly patients "ex-mechanics" "ex auto electrician certified" etc.) "find the short, for sure," and the same situation repeated itself. I forgot about it with her idle for a year. Now has another new battery replaced by indy (Interstate) and I just had to replace the alternator with everything else new (anyone want the last new one I bought - only a month or two's use on it) and I got one from Eagle Electric per multiple rec's on this site - Supposedly real Bosch or MB guts - and I bought an 85 amp one, just, ahh, 'cause a bunch a guys on this site thought an upgrade not a bad idea.
I noticed alternator light on in both car washes.
I drove 400 miles to Antonito CO and she ran really, really really well. I checked into hotel and came out to restart and NADA. Little click. Freaded out. Hotel owner came out with battery charger, system tester, and said "it's not your battery. It's actually overcharged - 16+ volts. We put the paddles on regardless and she started right up. Left her running damn near all weekend including at fillup twice. Started the few times I shut her down except once. But on 3rd or 4th attempt she started that time.

So: old problem, never rectified i.e., a short somewhere? Starter? Voltage regulator? Solenoid?

Also, appreciate the various advice from mechanic shopping (I've actually done this) to break-in stuff.
Oil update: indy finally answered my question on what he used: states that regular dino 10/30 is "great" for breaking in engines and that he filled, let tech drive a bit, drained and refilled, and recommended that I change at 500 miles with whatever I wanted which I did with Rotella 15/40 just prior to the Colorado road trip.
One other question. After road trip she now rocks and rolls in gear at stop lights - was remarkably quiet and indy billed for new motor mounts. Does this mean motor mounts are bad? Smooth and quiet as is possible at idle in park and smooth as silk on the road.
And, ahh, hey Tilac - me and a roller brush and a gallon of good paint? That's sacrilege and you know it. I couldn't paint my f'in fingernail.

I have to point out that the 70-75% engine power is during cruising. It stated full power during take offs and climbing. Just hitting the pedal in accelerating and climbing mountains. But yes hitting the red line is a no no. But these diesel won't hit that anyways if the tranny is shifting correctly or you have a manual transmission or your going like a 130 miles per hour.

__________________
1983 123.133 California
- GreaseCar Veg System

Did they reuse the old starter? If so, I would definitely start there. Seems like a solenoid issue. If it happens again, you might want to jump the terminals at the junction box just in front of the battery. Jump the terminal closest to the battery and the middle terminal to turn the engine over. If it works, then it probably is your starter.
See link on the junction box.
Junction box on inner fender for checking starter?

One possibility is your not getting the correct amount of fuel to the engine. Sometimes the vent line in the diesel tank gets clogged and the resulting vacuum limits the amount of fuel getting to the engine while at an underload idle. So my question is, Do you get a whooshing sound when you open the fuel filler cap? If so, then your vent line is clogged and should be corrected and may help with the rough idle.


BTW - Good job in the break-in. If your correct in the fuel mileage, then it shows your on the right track.

__________________
1983 123.133 California
- GreaseCar Veg System

Bolts have been known to loosen up after initial installation. Check motor mount nuts/bolts are tight. If your alternator is over-charging your battery, it will feel hot (the batt) and that points to a voltage regulator. Did the light come on only at a carwash? Get yourself a cheap voltage tester at Sears and stop guessing. Higher MPGs means motor has broken in. No more tickets Nubie!

Yeah, for $10 - $15 you can get yourself a digital meter to diagnose your charging system issues. With all the folks here in the forum, you're pretty much guaranteed that we can help you use it to track down the problem yourself. Of course, that's only if you're done paying people to diagnose it incorrectly.

__________________
- K.C.Adams

'77 300D Euro Delivery
OM617 turbo / 4-speed swap
404 Milanbraun Metallic / 134 Dattel MB-Tex

Current status:
* Undergoing body work

My '77 300D progress thread

Alternator light only came on at carwash and after the windshield wiper fluid dumped (hose disconnect). The only reason I overpay for wrong diagnoses is because I don't have a mechanical clue. I probably spent two hours changing the fuel filters while staring at a manual.
No whooshing noise when fuel cap removed - definitely was smooth as silk prior to trip to Colorado and definitely vibrates enough to rattle my pelvis now - only in gear when stopped. Hood is rock-steady running and same in park at idle. Started all three attempts today without incident apart from a split-second delay from key-turn to ignition. First week back it started so quickly, easily and quietly I thought it was a Lexus gasser. I hate the fact that I'm cringing/wincing waiting for the other shoe to drop every time I get in...
Does 16+ volts on the only reading (immediately after she wouldn't start after 400 miles of non-stop driving) mean anything here? 85 amp alternator vs. 65 amp? Starter and solenoid were NOT changed out with engine rebuild and again I had the miserable charging system fiasco(s) for months prior to timing chain meltdown although it had started okay for a couple months prior to that - but now that I think of it the alternator light came on during that period with long trips which it had NOT during the months of battery, alternator replacements and several "short" fixes by various people.

I must have missed something in the thread somewhere. The alternator has been replaced, yes? With an 85 amp unit? Was that alternator new, rebuilt, or used? Where did it come from? When, in relation to your charging system issues, was it installed?

Now, about that 16 volt figure... Was the car running or stopped when that was measured? Where was that reading taken from? Across the battery terminals?

I know most of this information is right here in this thread, but it's spread out all over the place. Let's condense it here and see if we can solve the problem.

__________________
- K.C.Adams

'77 300D Euro Delivery
OM617 turbo / 4-speed swap
404 Milanbraun Metallic / 134 Dattel MB-Tex

Current status:
* Undergoing body work

My '77 300D progress thread

You've got lots of knowledgeable diesel guys here Nube. They'll help get you sorted, don't despair.

Yep, and my electrical skills are decent. I've only ever melted one screwdriver and one wrench, and none of the houses and cars I have rewired have ever burned to the ground.

Okay, there was that one MG Midget that I accidentally wired the starter up backwards in, but that only happened because an idiot PO rewired half of the car with NM cable, (The stuff you wire houses with,) and somewhere in the mix of sorting and re-running wires, I momentarily forgot that the car was positive earth! Battling Lucas, The Prince of Darkness is one thing, but it get's really hard when the PO was apparently one of his minions.

__________________
- K.C.Adams

'77 300D Euro Delivery
OM617 turbo / 4-speed swap
404 Milanbraun Metallic / 134 Dattel MB-Tex

Current status:
* Undergoing body work

My '77 300D progress thread

Charging system issues are spread out and they are long and tedious.
The new(est) alternator is brand new from Eagle Electric which gets high marks on this site from multiple people. All Bosch or MB innards. Several people here recommended upgrading to 85 amp from 65 and the alternator is specifically listed for several MB models incl. 300D turbo. Battery is brand new as well - interstate - and put in by indy with rebuild as he said my battery was toast. That would be the third new battery (4th if you count that there was a 6 month old diehard in the car when I bought it from a good friend in 3-07. The immediately previous owner to him was his best friend who is a major gear-head and who used to build airplane engines, racing engines for porsche, etc. and he kept it up well.
I bought it in 3-07; by May I had my first "no start" so I jumped it, it worked, and then no start within a couple weeks. I took it to sears. They said the battery was toast and gave me a new one. It started fine for about two months. Then, no start. So I jumped it and it ran again for a couple weeks. Then no start, no jump. Took it to local backyard mechanic rec. by boss (weak recommendation) and he said: no prob. it's your alternator. He got a rebuilt alternator and installed and he promised "problem solved." Two weeks later, no start. Brought it back, and he said, "I don't understand. The alternator seems to be working at low speed but doesn't when it's revved. I'll put in another alternator." A week later: no start. Jumped it a few times cause I didn't have time to leave it with him for a week which is what it took him every time I left it with him and then, no start, no jump. Took the battery to have it tested at auto zone cause no Sears here and they said: battery's toast. Couldn't find a battery to fit it in town so I got the closest fit that I could hook up at Kmart. In between all of these times I had several - like 3-4 - patients who professed that they could find the short and fix the problem. One was sure that it was because there was a 5 amp fuse attached near the batter for the stereo. We disconnected the stereo and I lived without music. One of them found a cluster of wires practically burned into the metal on top passenger side engine compartment like, ahh top of wheel well. He said it should have had some sort of housing or another around it but assured me that he individually checked, twisted and wrapped the various wires and then, for good measure, triple-wrapped it all in electrical tape. For about two months before timing chain broke it started but alternator light came on intermittently. And then the timing chain broke in 1-08 and it sat until rebuild. The 725 amp kmart battery with all of about 2 months' use was toast according to indy. The existing alternator apparently worked but I want the new one put in so I've got a back up.

Thus the question: was whatever short/electrical problem I was having never fixed (lots of things were checked as I was on this site at the time hashing out issues - check all grounds, etc. and I found that lots of others have had perplexing problems like this with various answers) and therefore probs still pending: of note, the pattern was that it would start and run around town for weeks to months and then major declaration of problem ususally after 100 mile or more trips. This would fit the pattern. Did not start after 400 miles of straight driving. Voltage meter was direct from battery, not running - immediately after stopping from 400 mile driving. It was checked by the motel owner. It read 16+ amps and he said "alternator works and battery is over-charged. Despite that we hooked it up as if to jump it and it turned over right away. It wouldn't start one other time on the trip until about the 5th attempt (and I definitely warmed up the glow plugs each time) but has started since then. But it's only been a few days.