OM616 on a test stand
 

So I bought a 616.916 with manual transmission, I've never owned anything like this before so there are lots of new things to become familiar with. I intend to use it in something like a Model A speedster but I'm still looking for a chassis to start with. In the meantime I want to get the engine running well.

It came from a W115 that was being swapped to a 2JZ, owner said he drove it for a while with the 616 and always wanted to swap it. So when the starter failed he pulled the whole thing out and started the swap rather than fixing it. I have not tested the starter to confirm.

I built a test stand for the motor, just waiting for motor mounts to arrive so I can finish it up.
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I've been looking over everything and I was hoping you guys could help answer some questions I'm having a hard time with, since I never had a whole car some things are just unclear when looking at this.

1. Where does the valve cover breather tube connect to? On some pictures I've seen it goes to the fitting on the bottom side of the intake manifold, but there is no where for it to go on mine and I don't have the tube itself.
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2. What are the bolts on the intake runners for?
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3. What size bolts should fit into the front of the head? I normally work on Japanese stuff so I have a big bucket of random fasteners and nothing fits. Is the German stuff a different thread pitch? Or do you think the threads in the head may be messed up? How many bolts should the water pump have? I see some extra holes that don't have bolts in them.
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4. Where should the vacuum lines be plumbed to from the vacuum pump? One goes from the intake manifold to pull fresh air? And the other? I assume some sort of vacuum manifold would have been used to distribute vacuum to multiple places in the car? Can I send this directly to a brake booster if I use power brakes? If I don't use power brakes I assume I can just remove the vacuum pump altogether?
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5. How is the fuel cutoff arm operated? Pull back/up? What is that rubber mount for? Can I get rid of the mount?
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6. Can I block off the heater core water outlets on the side of the head and water pump if I'm not running a heater?
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7. Are 3 points of support enough for engine and transmission? I see some other brackets on the bottom of the engine and transmission but the only mounts I found for sale were 2 on the engine and the one on the tail of the transmission. Just want to make sure I'm not missing anything I need.

8. Is it common to have part numbers starting with 615 on parts on the 616 engine? I assume these are just leftover from the previous OM615 in the W115, and when Mercedes changed over to the 616 they didn't need to change any of those parts. Or do you think this 616 engine was swapped into this car at some point?
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9. Does this engine have 2 water temp sensors? I see one at the thermostat housing, at one on the side of the head?
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10. Do the throttle arm pivots look bent to you? Or are they supposed to be like that?
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11. Do I need the throttle butterflies in the intake? Could I remove them and use just a single arm from my throttle pedal to the injection pump? I've seen some other cars without them and I'd much prefer not to have all those pivots and rods running everywhere.
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Anything else you can see on here that I should know? My plan is to do the bare minimum to make it run just to make sure it's worth working on, then I'll do all the maintenance on it, oil change, fuel filters, valve adjust, tstat, etc...

Wow, that turned out to be a lot. I had to split it up due to the photo limit. Let me know if you guys want to see anything else.

you have a vacuum operated pump, do not remove the butterfly valve or the pipe running from the throttle to the pump.
the rod connected to the pump is only the idle damper, and can be removed if you want, just helps smooth low idle

heater pipe nipples can be removed AFAIK

the engine gasses where just piped into the intake before the butterfly assembly. can also be vented to outside if you dont care about certain things

water sensors, the one in the head is temp, the one on the coolant neck is a switch the triggers the aux fan

the vacuum pump, vacuum is on the port currently without the hose, the vacuum pump expels air in to the intake.
you dont really need a vacuum pump in the case, personally, I would get a block off cover and use an electric setup, just my opinion though

the large bolt bosses on the front are where the huge AC bracket would attach

I added numbers for the questions to make it easier.

Are you saying that the injection pump is vacuum operated, and that the line from the throttle body to the injection pump is required? That is the reason that I need to keep the throttle butterflies?

Which rod are you referring to?

Good to know, thank you.

Ok so then there must have been a nipple on the intake pipe that I don't have. Thank you.

Ok that makes sense since that one would be measuring the temp coming out of the radiator I think. I will use the one in the head and see if I can get away without an aux fan.

Ok so the side without the hose could potentially be used for a brake booster? I'm going to try to keep it to manual brakes so I will remove the pump if I can, but you said that the injection pump is vacuum operated? So does the engine produce enough vacuum for that without the separate vacuum pump?

Makes sense, thanks.

replied inline

referring to #2, pull out one of those bolts and see if they are banjo bots, if so, you are missing the pipe that you've seen on other cars.

You're missing some bits and pieces of crank case breather system. See this thread for answers to these two questions:
http://www.peachparts.com/shopforum/vintage-mercedes-forum/408294-oil-bath-air-filter-filling-oil.html

If you still have questions let us know.

The lever is operated by a cable that runs up to the dashboard, attached to the so-called "gorilla knob" that is used to start and stop the engine. The knob controls whether or not the injection pump will deliver fuel (stop and run), and also engages the starter when pulled all the way back. The rubber block is where the cable sheath connects to the injection pump. Pushed all the way forward the lever on the pump is in "stop" position. The default position is "run". Pulled back puts it in the "start" position.

You could possibly remove the rubber block, but you'll still need some arrangement for controlling the position of the lever. In the car the lever is held forward in the "stop" position by the cable. When disconnected from the cable the lever will default to the "run" position.

PS - Nice looking shop! :)

That's a great thread. Thank you!

Here's where I'm at with the questions. Thanks both of you for the help so far!
1. Solved - thanks resago2000 and gmog220d
2. Solved - thanks gmog220d
3. Solved - I think Toyota uses a 1.25 thread pitch while it seems like Mercedes was using 1.5 thread pitch.
4. Solved mostly - thanks resago2000, I need to research more about how vacuum pumps work.
5. Solved - thanks gmog220d
6. Solved - thanks resago2000
7. unsolved
8. unsolved
9. Solved - thanks resago2000
10. unsolved, i suspect it is bent
11. Solved - thanks resago2000, I think some of the stuff may be able to be removed but I will do more research.

Ok so is this labelling correct then?
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I'm having a hard time imagining the operation of the cable, you say that the cable holds it forward to the stop position by default? So you must pull the cable in the car to start the car? So the car starts with a cable and not with a key?

Does the "start" position on the pump modify fuel delivery at all during startup?

with the fuel shutoff, anything other than stop is run.
2 choices only

10. you dont need it. you can remove it and the rod running along the top of the valve cover if you want