Danke sehr, Albrecht.  Your explanation and excellent ASCII picture
cleared up my remaining confusion.

Folks, my mechanic suggested that he should change the oil and put in
some automatic transmission fluid to clean out the gunk that was
clogging my lifters.  I agreed, naturally with a little bit of
misgivings--it sounds so Arkie--and we went ahead with it.  I drove
away from the shop clattering like the snare drum section of a pipers'
band.  In two miles in had quieted down somewhat.  After five miles
there was only one tap-tap-tap left.  After ten miles it was All Quiet
On The Western Front.  Sounded like a new engine.  It so happened
I was right by a fireworks stand and I celebrated by buying a few
fireworks, something I don't ordinarily do....

Today we replace the oil with the regular stuff.  Hoping, of course,
that there will be no damage resulting from this funny method.

This has sure made a believer out of me on keeping the oil changed.
However, it does mystify me a little, because the oil was definitely
new when I bought this beast about 700 miles ago.  Could there have
been residual crud from previous laxness about changing oil?  Seems
plausible.

Arkansas residents please do not take umbrage at my aspersions.  I
myself am from SE Kansas only a stone's throw from AR and OK too.
My brother lives in AR.  I myself do Arkie fixes in areas where i
know what I'm doing, and am proud of them.

Will Self
Billings, Montana
'84 Vanagon