1971 250/8 Restoration Project

[1971 250/8]

I bought this a year ago and now have funds to begin restoration. Overall it's in good shape for a 47 year old Mercedes. Interior leather is in great condition with only a couple of minor fixable issues. The leather headliner is in great condition except it has pulled away from the rear window area. The body has minimal rust where water collects at the corner areas (minor MIG repair).
Project will involve: Engine rebuild (with carbs), complete body repainting (color matched), undercarriage coating touch-up and repainting (no significant rust issues seen so far), front windscreen replacement (cracked) and full weather seal replacement. Brakes, differential, transmission will all be inspected and rebuilt as needed.
My goal is to take my time, love the work, and document as much detail as I can. I really love the mechanics of this car and will enjoy this project over the months to come.
Phase 1: Engine/transmission/carburetor
Phase 2: Wiring Harness rebuild
Phase 3: Brakes/Suspension/Driveline
Phase 4: Interior
Phase 5: Painting
Phase 6: New exhaust (manifold to tail)



"I don't quote people"

[1971 250/8]

The engine was running until the previous owner began messing with the carburetors.

Assessed engine first; removed header and it's a pretty ugly block. Rear carburetor burning rich, forward burning lean. Disappointed to see piston header impact damage on one cylinder (machine shop says it can be machined). Applied straight edge to header and there isn't any warpage or gaps. No obvious gouges in the cylinders.
Next step is pulling the engine and taking it apart to see what caused piston impact damage (suspect loose piston? hopefully)
Not entirely sure at this stage if engine is rebuildable, lucky to have a machine shop pro to help with diagnosis.

Also uploading plate data pictures. This is one of the "less obvious" 250's with a 2.8L M130V carbureted engine (114.011)



"I don't quote people"

[1971 250/8]

Rear carb burning lean, front burning rich. Carbs were seriously out of adjustment, I believe it was the rear carb that had a jury rigged wire going to the sensor.

[Mike D]

Two suggestions.

#1: Replace the steering gear box mounting bolts and torque them to specs. Checking the torque on them should be a part of your annual inspection.

#2: Replace the antiquated Kettering ignition points set-up and install a Pertronix Ignitor and coil. You can leave the transistor box in place if you are concerned with it looking "original" but disconnect the power feeds.

[1971 250/8]

Pulled the engine and transmission with my son. Of note is the custom car dolly we made out of 2" x 10"s with 1000 pound capacity (each) wheels that I found on Amazon. Moves around easy with one hand. (The fixed jack inserts on the frame fit perfectly inside the jack stand slots. A cut section of bike tire tread provides extra mating grip. It's solid mating and will not slip off. Whenever working under the car, I always put additional blocks for secondary safety. Never putting my life at risk to a single system)

Also manufactured an engine/transmission dolly/workbench using a 1000 pound furniture mover affixed with raised boards. (It moves easy too)

Next steps are engine degreasing and disassembly. (next posting in a week or so)



"I don't quote people"

[1971 250/8]

Originally Posted by Mike D

Two suggestions.

#1: Replace the steering gear box mounting bolts and torque them to specs. Checking the torque on them should be a part of your annual inspection.

#2: Replace the antiquated Kettering ignition points set-up and install a Pertronix Ignitor and coil. You can leave the transistor box in place if you are concerned with it looking "original" but disconnect the power feeds.

Thanks Mike D. I'll be taking all the experienced advice I can get. I'm not too concerned with keeping everything "Original" as this is a keeper/driver where better performance is preferred over rigid factory settings. That will include upgrading the fuel pump.

[Shortsguy1]

Great looking car! (not that I am biased as the owner of a 68 220d). Is it light beige (like mine) or white? Good luck with everything.


Also, what state do you live in? I have glass and other parts which might be helpful, but it would not be worth shipping anything.

[1971 250/8]

Originally Posted by Shortsguy1

Great looking car! (not that I am biased as the owner of a 68 220d). Is it light beige (like mine) or white? Good luck with everything.


Also, what state do you live in? I have glass and other parts which might be helpful, but it would not be worth shipping anything.

Wow! I’m in Lemoore. I’ll definitely be forwarding a parts list as this progresses.

You are seeing two colors actually. The tag color is 670 H, Light Ivory, but hood and one quarter panel are beige white. No evidence of a collision... these may have been replaced due to corrosion or dents.

[1971 250/8]

Degreased the engine well enough to separate transmission from engine;

Prep for separation went smooth except for one clip securing one transmission line to the transmission body on the left lower side (it was stripped... so I cut through the metal clip which will be easy to replace).

Removed transmission face plate giving access to TC mounting bolts.

Marked the torque converter in relation to the plate with red paint. Removed 6 mounting bolts by rotating the engine shaft clockwise (while holding timing chain snug).

Removed grounding strap bolt with size 10 allen socket (this also frees the starter)

The remaining nuts and bolts securing trans to engine are 17mm... except for one that is 19mm (Mercedes is weird that way... no clue why one is 19mm)

Secured TC into the transmission (in photograph). Then mounted transmission to stand vertical using a tire as the base. (The plywood is bolted through the tire rim holes which you cannot see in the picture... then up through donut mount for a secure fit). This will allow easy work on the transmission.



Next week or so will be engine disassembly.

[1971 250/8]

I have included the header/piston surface damage photographs. I won't really know the full story until engine disassembly, but the damage appears limited to the compression top surfaces (no gouging on piston walls that I can see). Something got in there... and got pulverized.

Next week I'll have it all apart.

[tyl604]

How the heck did the engine get that greasy????

[1971 250/8]

Originally Posted by tyl604

How the heck did the engine get that greasy????

If you are referring to the pulled engine on the dolly, pictures were taken after spraying Gunk Gel to soak.

[tyl604]

Thanks; was wondering. Could not tell what it was.

[1971 250/8]

Tore the engine apart. There were 5 stripped allen head bolts on the lower block tray. (easy to see how this happens... no gasket... metal on metal... mega torque on short head allen bolts... I'll be checking around for deeper head replacement bolts).

Good news is the main shaft looks great... no scoring. I'm certain this engine has been overhauled before as the pistons were already marked 1-6.... and the shaft sat nice and tight.

I'll be replacing two pistons so far. #4 I already knew about, it had the impact damage issue. #6 caught me by surprise... about a 3 inch section is broken off on the ridge that separates the piston groves. Any idea how that happens? Good news is it didn't gouge the cylinder wall... seems that it 'miraculously' just floated between rings.

Next stop is the machine shop for their inspection and estimate. I might try two shops and go with the most competent. Not planning to do that until April.

So I'm on break... no sense spending money on any other work until I get the engine rebuilt and running.

[1971 250/8]

Sharing pictures of where markings are located on the M130.923 engine.

Aside from engine type (M130-923) I do not know what the other markings mean.

M130-923 specs: 2.8L, 2778.44cc, Inline Straight 6, Bore 86.500mm, Stroke 78.800mm, Fuel Petrol (1971 250 Sedan)



"I don't quote people"