1971 Mercedes 220 (W115 Chassis, M115 Engine, Manual Trans.) Project

[robadesso]

Hello all,

Warning: I probably put too much heart/information into this story so please don't be afraid to skip ahead to the issues.

Back Story:
I've been working on a rusty old 220 for a few years now and I believe I will be ready to get it running after extensive rebuilding and checking for any other issues that would tell me that this engine won't run / pass inspection.
I've been lurking around these forums for long enough to finally come across information I can't find. I was able to find an extensive manual that provides most of the information I might need but there are a few unclear things that I feel are essential to making sure nothing breaks when I attempt to start her up.
I bought the car when I was 18 to teach myself how engines work and boy has it a been a worthwhile learning experience.

Main Story:
When I bought the car, I was told it had a broken timing chain and that prior to that, it ran fine. The guy didn't seem to know much about what really went on with the car or he was just bs-ing me, the car is covered in rust, missing radio, missing A/C unit, but otherwise a beautiful interior. None the less, the main problem seemed to be that the intermediate gear (no. 9 in diagram) had rip a third of itself off. So I replaced it, cleaned off a significant amount of rust and tried to start it (in a matter of a few months). After getting it to run for ~30 seconds, a snap and a sputter were 2 sounds that broke my heart. the chain had actually snapped this time and took a few teeth from the new gear with it. The cause seems to have been that there was tension on the camshaft from the tower that holds the oiling rail(proper name?) and that the screws I replaced for the accessory pulley had ripped apart the oil seal. After a few years of on and off work on the car (free time was few and far between because of schooling and work), giving up on the car entirely once or twice, and replacing many parts that I had personally broken (starter solenoid and front camshaft tower/bearing) or found out were missing/previously broken (leaking clutch master cylinder, a seized heating riser in the exhaust, many bolts, and many washers), I believe I'm finally a day or two's work away from running this car, as close to factory spec as possible.

What Needs to be Done:
1. Pick up Clutch master cylinder from Hydraulic shop with new seals and hone, place it back in the car, put fluid in and bleed to remove air bubbles.
2. Make sure the distributor is in working order and timed properly (The engine certainly gets spark after sending a full spark through my chest and back into the frame a few years back). The innards are a bit dirty and there's a detached copper wire that needs to be placed back where I hope it belongs.
3. Make sure starter and alternator wires are all in the right places. It was hard to tell because I replaced the entire starter withe a re-manufactured Duralast one from autozone.
4. Adjust valves to factory spec
5. Put everything back where it belongs and try to start her up.
6. If the car ends up running, fix headlight wiring, get rid of all of the rust, weld on some sheet metal were the rust really had its way and claim her as my own.

Main Issues:
1. Attached is a document showing the timing area. The object described as '8. locking screw' in most of the images is puzzling to me, I'm worried because the one in my car has chain scratches all over it.
2. How to properly time the distributor or can it be easily done by eye.
3. Anything else that I may have missed from being young and inexperienced.

Addition: I will post pictures of problem areas as soon as I can including additional diagrams that might help. I'd be incredibly thankful for any help that can be offered and look forward to the discussions.

[jenno]

Please check timing chain tensioner and rails. Why did the chain snap?
When you replaced it and had turn the cam to bring into proper position for the TDC of the engine did it bind since you replaced the first cam bearing? Did I read that right? Turn the engine through by hand with plugs out first! Before starting.

[robadesso]

Originally Posted by jenno

Please check timing chain tensioner and rails. Why did the chain snap?
When you replaced it and had turn the cam to bring into proper position for the TDC of the engine did it bind since you replaced the first cam bearing? Did I read that right? Turn the engine through by hand with plugs out first! Before starting.

What should I be checking for with the chain tensioner and rails? I was told that the oil pressure tensioner tends to fail by leaking and I will be checking it before I run the engine.

I haven't given the engine a full spin yet because I need to place the chain master link on the next time I get to the car, hopefully Monday morning. The camshaft did not bind after replacing the cam bearing, I had dipped the entire part in engine oil for fear of scratching it up/binding.

I did not know it was necessary to turn the engine through without the plugs in but I do faintly remember hearing that somewhere and I will be trying that next as well. Should I make sure a vacuum is created or is taking them out solely for the purpose of avoiding compression when turning the engine by hand?