Requesting help interpreting camshaft code

[MagicBus]

Hello, all

As some of you know, I'm nearing the end of a long project - the garage "restoration" of a 1983 MT 240D.

Today, I'm attempting to measure timing chain stretch with the 2mm lift method.

The first step (as far as I'm concerned today) is determining exactly what I have under the hood. So, I have the valve cover off, and I'm trying to determine which camshaft I have. I have a 616.912 I believe is original to the car. The FSM (the printout of which I left in the garage...) mentions several different camshafts by number.

I can't get my head in there to see, so I wedged my camera in there for a couple of pictures (below, and slightly cropped/rotated/zoomed/enhanced).

The thing is, this looks (to me) like camshaft code "H 19". However, I can't find any mention of any such camshaft code in the FSM procedure. I seem to remember a 6, an 8, and/or a 10, but not 19. (As I said, I forgot my printout in the garage - I'll go grab that in a few minutes).

Looking at these pictures, what's everyone's best guess on my camshaft code? If it is indeed 19, then where do I get the specs for checking timing chain stretch via the 2mm lift method?

Thanks in advance.

[MagicBus]

Originally Posted by MagicBus

The thing is, this looks (to me) like camshaft code "H 19". However, I can't find any mention of any such camshaft code in the FSM procedure. I seem to remember a 6, an 8, and/or a 10, but not 19. (As I said, I forgot my printout in the garage - I'll go grab that in a few minutes).

Note - I just grabbed my printout and the camshaft codes I see listed are as follows:

02 and 06 - which apply to the following engines:
615.912/913
615.940 (40kW)
615.941
616.916
616.912 (48 kW)

10 - which applies to the following engines:
615.940 (44 kW)
616.912 (53 kW)

[joshuajeeper]

The 19 (or any of the other listing) refer to the version number within the part number. That is camshaft number 616-051-19-01 which is a direct replacement for the 10 (616-051-10-01). That means at some point in that engines lifetime, the camshaft was replaced. For the 2mm method you want to use the specs for a '10' camshaft.

Hope that helps.

[leathermang]

I agree it looks like a 616.912...
I have my paper NA engine manual out....
Can you tell if the cam and caps are chilled or not ?

Ok.... if the ' 10 ' cam is correct... then with a new chain..
intake opens at 9 degrees after TDC

closes at 15 degrees after BDC

Exhaust valve opens 27 degrees before BDC

Exhaust valve closes 16 degrees before TDC..

[MagicBus]

Originally Posted by leathermang

I agree it looks like a 161.912...
I have my paper NA engine manual out....
Can you tell if the cam and caps are chilled or not ?

Thanks for the quick response.

Honestly, I have no idea what you're talking about, nor do I have any idea how I'd determine that.


These are two relevant screenshots from the StarTek online FSM:

[leathermang]

That is the page I am looking at in my paper manual....
Have you read the threads listed in my signature on timing ?

On the page showing the offset woodruff keys available ... 05.4-215/5

"""8. Continue to turn the crankshaft in normal operating direction until the small dial gauge pointer has dropped by 2mm ( valve lift) to 1mm.

At this position , the reading on the balance plate must agree with the specification' intake valve opens'..... """

[MagicBus]

Originally Posted by joshuajeeper

The 19 (or any of the other listing) refer to the version number within the part number. That is camshaft number 616-051-19-01 which is a direct replacement for the 10 (616-051-10-01). That means at some point in that engines lifetime, the camshaft was replaced. For the 2mm method you want to use the specs for a '10' camshaft.

Hope that helps.

That is exactly what I needed to know. Thanks.


This also lends credence to my theory that the timing chain was indeed replaced (it would make sense that it would have been done at the same time as the camshaft).

In the previous owner's papers, I saw a very vague reference to timing chain replacement, but not actually a statement that it was done. From what I can see from above, the tensioner rail has no wear on it. Also, it's an IWIS chain.

That last bit of info doesn't necessarily mean the chain was replaced, but does mean that if it WAS replaced, they used a quality chain.


This car's an oddball, in that it it was cosmetically-trashed. But, I've found Mercedes part number stencils and stampings on everything I've touched on the car. My theory is that whatever work WAS done on the car was always done with quality parts. I think the car received better care mechanically than cosmetically.

[MagicBus]

Originally Posted by leathermang

Have you read the threads listed in my signature on timing ?

Not recently (as in the past week), but I have seen them. I have been doing my homework on this.


But, if 19's a direct replacement for 10, I can move forward with that knowledge.

[leathermang]

Actually it would more than likely indicate replacement of the sprocket on the end of the cam rather than the cam....

If you have everything off the front of this engine...
you could install one of the one piece chains like was done at the factory...

[MagicBus]

Originally Posted by leathermang

Actually it would more than likely indicate replacement of the sprocket on the end of the cam rather than the cam....

There's quite a few responses in this thread already. Not sure which comment this is a reply to. If it's a reply to joshuajeeper's comment on the part number, I don't see the correlation between replacing just the camshaft sprocket and the number on the aft (firewall) end of the camshaft.

Originally Posted by leathermang

If you have everything off the front of this engine...
you could install one of the one piece chains like was done at the factory...

One thing at a time.

If this chain measures OK, then I plan to leave it in place and simply monitor chain stretch with every valve adjustment.

Oh well - time to grab some lunch and then head back out to see if I can determine chain stretch. I'll update this with my findings later.

[Stretch]

Code 19 == after June 1982




http://www.peachparts.com/shopforum/diesel-discussion/369554-om-615-woodruff-key-replace-timing-chain-2.html

[leathermang]

Nice find Stretch... wonder why my English language 1991 paper manual does not have that... the specs are the same for the ' 10 ' confirmed by joshuajeeper so that is nice to know..

[MagicBus]

Indeed that's a great find. I don't have a paper version of the engine manual (though I do have a paper copy of the chassis and body manual).

Good for all of us to know that the 19 camshaft follows the 10 in terms of specs.



OK - I very carefully went through the chain stretch test and, although my crank pulley/balancer marks aren't the easiest to read, I got a reading of somewhere between 13.5º and 14º at the crank (once again, it's just not too easy to read on mine, no matter how I try to clean it.


Unless I'm mistaken... I'm actually right on the money here.

I'm going to measure again (measure once, cut twice, after all...), but assuming my reading is correct - it looks like I'm good to go.

[leathermang]

What method are you using for the chain ' elongation' test ?

[MagicBus]

Originally Posted by leathermang

What method are you using for the chain ' elongation' test ?

2mm lift test per the FSM and the several available online writeups, using a dial indicator on the cylinder 1 intake valve.

That's the preferred method, right?

It's my understanding that attempting to line up timing marks on the camshaft is only applicable to new engines and/or new timing chains.


Incidentally, I just ran out to the garage and went through the test again. I got an identical measurement. Unless I'm mistaken, I'm well within spec and good to go.

I know that there's the possibility that there's an offset woodruff key in there, but for now, I'm not likely to worry about that.