As I've mentioned several times over the past twelve years, when three
or more people ask the same general question in a relatively short
period of time, I take it as justification to post a comprehensive
covering not only the questions asked but the subject in general.
That's how the so-called 'sermon' files came into being.

The individual questions still get answered, if they've provided a
valid address. I know that sounds crazy but an awful lot of people
don't. Two of the valve-train questioners provided addresses that
bounced my reply. Of the other two, I told one that his push-rods
appeared to be too short, which got me an ear-full of 'that can't be
right.' The other fellow had worked out the input-side of the
equation okay but was hung-up on achieving tangency at the output,
with several indications that he needed to shorten his valve stems OR
the arc of the rocker-arm, meaning he'd need to reduce the length of
his adjusters -- possibly even grinding away about sixty-thou from the
under-side of the threaded portion or the rocker-arms so as to allow
his elephant-foot adjusters to be screwed-in a bit more.

This really is pretty basic stuff, the sort of thing you can figure
out for yourself if you'll just think about it for a while. But it's
a topic that starts BEFORE you assemble the engine and has little in
common with the same task on a water-cooled engine, where only the
OUTPUT side of the equation is addressed. (Why? Because the heads --
and the rockers -- retain the same distance to the center-line of the
cam, which is to say the factors on the input-side of the equation
don't change.)

The major stumbling block is all the 'experts' telling the newbies
that they don't need the correct cam gear, that dialing in their cam
isn't necessary, and they only need concern themselves with the output-
side of the equation. That horribly wrong advice guarantees the
newbie will NEVER achieve proper valve-train geometry.

When addressed in its entirety the Volkswagen's valve train geometry
isn't something that lends itself to a quickie message via email.
Fortunately there's plenty of information out there, from such experts
as Lawrence, Ricardo and Taylor. Most of it dates from the 1920's but
the problem -- and the solution -- has not changed. There's even lots
of VW-specific valve-train information out there -- there's at least
two comprehensive articles in my blog (Dialing in Your Cam and Valve
Train Geometry) plus several others on basic head work. That's the Up
Side.

The Down Side is that the most common reward for answering questions,
pointing people toward sources of valid information and telling them
to THINK FOR THEMSELVES... is a file full of Snotty-Grams from the
idiots..

-R.S.Hoover