jpitman2

kEN,There are L jet 16v cars as well as CIS ....so are all CIS cars woodruff keys? Mine is CIS at 83 being Euro, but will I have woodruff keys?
jp 83 etc

PorKen

Glen,

The part numbers above are used on most Mercedes engines from 63-93, so they should be available through any import parts place or Mercedes dealer.

WorldPAC, which is the drop-shipper for most of the internet shops, lists them. I was able to find them all over the internet by specifying a 1980 300D. (They range in price from US-$6 to $8, each.)

When listed for the Mercedes, they are listed as being 2, 3, 4, 5 degrees offset, but the camshaft is a different size, so that's why I had to recalculate for the 928 camshaft.
...

jp,

I was being US-centric. The manual only shows them being used through 79.

GlenL

Gonna try this.

The right-side cam is 1/2 tooth off. With 48 teeth, that'd be 3.75 degrees. So I'd need the smallest one to get close.

Looks like the math is right. Anyone tried this yet?

If you google for "mercedes offset woodruff" there are a bunch of sources around $7.

PorKen

Glen,

I haven't tried it.

I haven't checked yet if my early '80 has woodruff keys, but if it does, I will go this route.
...

As I read it, the 'plus one' concept is still confusing to me, so I will try and restate it.

For example say you need only 1° advance. Install a 1.3mm offset key, with the offset towards retard (CCW). On the cam gear, put a paint mark one tooth advanced (CW) from the notch, and install the gear. When the belt is installed, instead of lining up to the notch, line up to the paint mark.

Now the gear is advanced 7.5°, but the cam is retarded 6.45°, which leaves 1.05° advance.

PorKen

Glen,

You could go with a 1.1mm(0) on the right side, and a 1.1mm(+1) on the left, for an overall 2° advance; for a little extra perkyness at the stoplight.

GlenL

Ken,

Wish I had the dyno time to get into this. Ran a compression test and the right bank was all around 151 and the left, which is right on, was 3 160s and one 155.

Hoping this touches up the right bank. At the valves were closing 7.5% later on the compression stroke, it makes sense that the net pressure was lower.

GlenL

Follow-up:

Got the 0.7mm key to adjust the right-side cam. Contrary to my recollections, my car does have the square keeys on the cams. Not really a problem as the MB key is the correct width and could be ground down to the right shape.

I installed the key a few months back. Just got to the compression test today. Very happy to see the right side (5-8) gain around 10psi to be around 160psi. This is the same range as the left.

My conclusion is that moving the cam back to spec from off a half a tooth improved the compression and made the sides balance. A nice result.

Thx, Porken!

PorKen

Glen,

So the ground down key fit OK? That's cool!

My life would have been much simpler if I'd gone that route from the beginning.


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