Machine shop will be diving into a tear down with us Monday or Tuesday. Will report the full findings with measurements. Thank you for all your input!!

Sorry, I guess post 1 does show a shiny spot fore or aft. In post 26 & 27, it looked like the shiny areas were on the sides. Hard to tell from photos, without being there in person to view all around. I would think you could tell if there is any fwd-aft binding as you attach the connecting rod to the crank. Seems unlikely since there aren't any thrust bearing surfaces between rod and crank and I think the rod is free to move fwd & aft a bit on the crank until it bumps into the crank arms (way off, and would be noisy), which is true of most engines. I think managing the crank's axially position (thrust bearings) is more for other issues like the seals and transmission interface.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

So due to pure impatience, we yanked one piston before the tear down with the machine shop guys on Monday.
The deck is marked with the arrow pointing to the front of the car and DS (Drive side) and PS (Passenger side).

The rods and rings were installed in the proper orientation and both rings gaped at .60mm at the top middle and bottom.

The cylinder shows abrasion all the way to the bottom of the bore.

What do you guys make of it?

Being curious I googled 'new liners and engine bore damage' selected images and then just looked for a relevant image similar to yours , after finding a suitable image similar to yours its just a matter of then using it to go to its original page / post .
Here below is interesting reading .
Engine smoking badly after rebuild... HELP PLEASE!... - Page 1 - Engines & Drivetrain - PistonHeads

Based on the last pics, I vote for piston skirt clearance being too tight.

Piston diameter needs to be measured in a very specific location as they are not round in diameter and not a perfect cylinder . Pistons are made oval with the wide dimension 90* to the pin and barrel shaped top to bottom. This is done to compensate for piston expansion.

Most importantly, what is the history of this engine and what parts in the bottom end were replaced?

The wear does appear to be on the sides, not fwd & aft as Stretch thought he saw (post 47). Regardless, I don't see any way that any binding of the connecting rod at the crank could apply significant force to the cylinder walls. Too-tight rod bearings on the crank would cause instant failure there. The only other possible binding might be the piston not free to rotate on the rod pin, but surely that would have been noticed.

I 2nd the incorrect or non-optimal cylinder honing. The best honing machines actually make the cylinder round and can take material from one side preferentially to get the center-line in the proper place. I saw one in use on a TV show and you could hear the sound change as it worked on different parts of the cylinder. It is more like a milling machine. More likely, they used an automated honing machine that works more like a hand-held drill hone. Those mainly just add scratches to the walls, but don't make the cylinder round or uniform.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

It is good to clear up that it is side to side wear.

@Garage Yourself what does the piston look like? Is there anything noteworthy on the side of the piston that corresponds with the "stain" on the cylinder walls?

Were the ring gaps nicely positioned at 120 degrees apart when installed?

I've made some notes on one of your pictures to help the investigations



I'm assuming ring "A" is the top travel of the upper piston ring and "C" is the bottom travel of the lower piston ring. Are these marks feelable ridges?

I'm think that "B" might be the top travel of the lower piston ring - can you check that dimension with the piston?


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Do you know if, when the cylinder sleeves were fitted, they were bored to the correct diameter as well as honed?

Attached Thumbnails

 

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

The only way to be sure is to mic the bore (using a bore mic or telescoping feelers), and then mic the piston. No guessing required
Also, the cross hatch does not look right... which is a sign that the machine shop did not know what they were doing. It is possible that they took too much off using the boring bar, then failed to hone it properly once they saw that the bores were too large.
The vertical abrasion lines are probably from improper cleaning prior to re-assembly, then the debris getting past the rings and lodging under the piston skirt.
A proper hone job followed by running the engine properly to bed the rings might help, but only if the bores are within spec.

Thank you for all the input. Machinist is scheduled to come at 4pm, I will address questions, post additional pictures and share the results of their measurements this evening.

Piston ring gap location is meaningless once the engine has run for any length of time as the rings rotate around the pistons. And ring gap location would not cause this type of failure. I space ring gaps away from the skirts just to keep the sharp ring gap edge out of a more critical area.

I've pulled engines apart that had ring gaps all over the place including mostly lined up.

Tight wrist pins could cause this type of failure but that should have been noticed at install.

At any rate, this isn't a common failure on a fresh non overheated engine.

Never soak piston and assembled rod components in varsol. I was going to mention this earlier but did not as expected it was not the issue. Plus the tight wrist pins would have been noticed on installation.

Any verdict?

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1982 300D Turbodiesel, daily driver. Mods so far: Fram 8038 paper filter, 4 brake light mod, Gen II w126 (front) rotors/calipers, boost turned up to 12lbs, non-egr manifolds, water/methanol injection, 4-speed manual
1980 300SD Turbodiesel, project car, nearly ready to hit the street

1974 240D, New paint

I agree w/ Kestreltom. After reading the link in post 49, the photo in post 53 shows horizontal boring marks which shouldn't be visible after a proper honing.

I have read different things about rings spinning in the piston grooves. One story is that when GM first switched to robot assembly, they installed rings with all the grooves aligned. That caused excessive oil consumption. Might be an apocryphal story since if the rings do spin they would soon randomize the gaps. I can't envision them spinning since seems like the sharp ends would dig into the aluminum to lock them in place, and if it spun seems it would machine away the aluminum grooves like a turning tool would.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

Video link of broken down engine:
https://youtu.be/CTMSK2W5J9I

Machine shop has been a no show twice, scheduled again for tomorrow morning (Thursday).

MurkyBenz:
Thank you for research, I find the conclusion of an over or under bore to be likely. I will also use your method of searching in the future. Very effective!

97SL320:
Measurements to come when the machine shop makes their appearance.

Bill Grissom;
The wear is on the left and right side of the bore, not fron and back

Stretch:
The rings were properly oriented your diagram is correct.
New sleeves were bored and honed, to the right size is the question of the day (Again waiting on the machine shop for measurements).

Kestreltom;
The vertical scoring marks are likely from foreign debris, as some was found in the pan. This sources is believed to be the media left behind by the same machine shop's reconditioning /cleaning procedure of the pistons.

97SL320:
Wrist pin motions are all smooth as silk.

The machine shop has been in contact, and has rescheduled for Thursday morning. All of your input is greatly appreciated,with support this girl will rollin' again soon!!!!

It's appears to be evident the engine has to come out of the car. I do not presume to tell you what to nor am I suggesting you do that which I would, I'd take the engine to a location that I could get a dial bore indicator inside the cylinders and see for myself what the size hole really measures.

In my case the person who bored the sleeves would probably tell me that I gave him the dimensions and they are exactly what I had specified.

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84 300SD
85 380SE
83 528e
95 318ic