First of all, my 88 300E has 279,000 miles with original chain and components. This particular engine probably has a system that is as robust and reliable chain system of any MB engine.

Secondly, Hatterasguy, with all respect, having a gear system, rather than a chain system on an overhead cam engine of any kind is a totally impractical approach for anything short of an all out, no holds barred, double throw down race engine. It would take a number of gears to link the distance between the crankshaft gear and the cam gear(s.) On an OHV engine, it can be done with as little as two gears because of the cam being very close to the crankshaft. When the shafts are far apart it takes a number of idler gears to make up the distance. That means that with all those gears, the slack will add up and make for a very sloppy system with poor cam timing after not too many miles of wear. There is no way to take up the slack in gears as they wear as you do with a tensioner on a chain.

In a race engine, these gears would be replaced often, in a street car you would not want to do that.

Additionally gears are typically noisy, a characteristic that MB goes to a lot of trouble and expense to engineer out of their cars.

Have a great day,