The overheating explains it. The heads started to melt and castings tend to
explode when overheated. Try welding castings! Gotta know what you're doing.
There is a good chance that case is also toast.  Could be
warped-twisted-cylinder seat damaged. Replace the studs as they are also
stretched.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
HotelWestfalia
Sent: Monday, February 13, 2012 9:56 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Erosion between valves

First time I've seen this.  Very deep erosion around the spark area.  Next
to the valves.  Between the valves, cutting under the valve seat.  Only
three cylinders had it.  The heads had to be junked.  Deep, sharp pitting
like, picking like erosion.  About 5mm deep.

I don't have a sure idea what caused it.  Surely it is related to ignition
or explosion or something of that kind.

This engine has overheated badly.  One of the cylinders has even melted.

I wonder, if anyone has seen any of this before.  And if any of you know
what caused it.

Best to all,
Zoltan