Date: Mon, 13 Jan 1997 12:56:18 -0800
From: Mike West <mwest@cdsnet.net>
Subject: Valve Train Lubrication

Another little known part of the valve train "Assembly",
is the lubrication system going on in there.

If you look at a case, you will see there are oil galleys
running to the cam lifters.

That seems proper, yes?

Now look at one of the lifters. There is a hole in the side of
it and it connects to a hole in the top, where the push-rod end
fits in it.

Now look at the push-rod. There are holes in the ball ends and
the push-rod is hollow tubing.

Now if you look at the rocker arm, you will find a hole in the cup
where that meets the push-rod.

Then there is a passage drilled from the cup, into the bearing that
rides on the rocker assy shaft. Look at the outside on the end you can
see where they then welded the hole closed .

Around on the adjuster screw side of the rocker arm there is also a
passage into the main shaft bearing.

 Oil from the main shaft works it's way down to the adjusting screw.

I assume the oil works down the threads of the adjuster screw to lube
the top of the valve stem.

If you're using the "swivel foot adjuster", there is a passage under
the swivel foot that connects to this rocker passage.
 Major improvement.

So several things to watch out for when you build one of these pups:

The lifter to bore has a tolerance of wear. See the Bentley manual.

Exceed that and the oil is just going to leak out around the lifter
instead of being pumped up the push-rod.

In fact the hotter the oil, the thinner and therfore more able to leak
out and then less still goes up to the valves.   Woe! !

The ball ends on the push-rods are all that holds the oil in there,
so any burrs or dirt etc. and you're SOL again.

They have to be a fine polish and fit the cups perfecto.

Tooth paste by the way makes a fine polish. Cigarette Ashes too.

Make sure the push-rods have a clean clear passage thru them prior to
assembly.

It would be a good idea to fill the push-rods with oil by submerging
them in oil before you install.

Some will drip out when and after you install, but at least they won't
be dry.

Make sure all the passages in the rocker arms are clean and clear
before you assemble the rocker assembly.

Altho there is oil mist and oil being thrown around in the rocker box,
this is where most, if not all of it comes from.

I might also add this is the only cooling the valves get.

I think I like the idea of a breather being there on the rocker box
cover, sucking cool air in and sucking it out at the filler tube on
the other end of the engine.

Some of you may not know it but VW them-own-selves put a breather tube
of this ilk, in the left hand rocker box on the type 3's.

Get a damn oil filter on that engine, you have any idea how easy it
is to plug one of those passages with even the finest dirt/carbon?

The sky is falling! the sky is falling!  :-)

There still are some shadows around so I keep on pushing,

 west