Date:         Mon, 21 Oct 1996 23:10:23 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         ewalt@transbay.net (E. W. Dahlstrom)
Subject:      piston wear and compression


        Hello to all you vanaganers and bussers.
Been voyering a bit over the past two years, just enjoying reading of all
your adventures and wacky Friday stories.
        But, unfortunetly, I've run into a missadventure with my 82' Westy
and I need to ask for some assistance.
        I recently noticed a drop in power on hills and on start-up so I
did the usuall tune up tests.  Upon checking the compression, I found that
#1 was at 30psi while the rest were at 125.  Oil in the cylinder made no
difference.  So I checked the torque settings on the head and they were
fine (I retorqued the heads once after I did a rebuild about 20k ago).  The
next step was to remove the head to see if something was amiss.  I pulled
the head off as well as the cylinder and noted that the leading top edge of
the piston (side wall) was worn and blackend but still seemed to be round.
The cylinder does not appear to be worn as I can still see the honing marks
and, as well, the lower part just below the rings is as clean as the rest
of the piston.  The valves seem to seat well.
        So, the question:  Why would the leading edge of the piston wear
like that and would that cause the drop in compression?  I would assume
that the rings are still doing their job as there is no oil consumption or
blue smoke.
        If that is not the problem, what else could cause this drop in
compression.  As I said, the valves seem to seat well, the rings are in
good shape and the cylinder still looks very good.
        If you like, you can email me directly or to the list.
                Thanks in advance
                        Walt in the Bay Area.
k;;;o