While looking at the diagram on page 2 of the timing chain tensioner they show the oil going in and 2 places where the oil goes out. One of the outlets looks goes parallel to the plunger as if it is made to be a spray jet. The other outlet is at the eng of the plunger housing could also act as a hole to let the oil lubricate something.
I saw this myself as I made a mistake and bought a new Timing Chain Tensioner on Ebay before I knew the Turbo and Non-turbo engines had different ones. So I had the real part to compare with the diagram.
http://www.pauldrayton.com/uploadfiles/merc/Service/W123/w123CD2/Program/Engine/615/05-310.pdf
It may get a lot of lubrication from is the oil coming out from the Fuel Injection Pump Timer. I would think that ounce the oil is done lubing the Timer/Timer Bearing it gets flung out onto the chain.
Probably the same thing happens with the Front Camshaft Bearing. Ounce it is done lubing the Camshaft Bearing the oil will come out onto the back of the Camshaft Drive Gear a probably gets flung with quite a bit of force from there.
Likewise the oil coming out of the Front Main Bearing should help to lube the chan and Crankshaft Gear.