Thank you to Dave & Mark for their stories & photos of "dropping a valve" in July. I worked as an aircooled VW mechanic for 3 years in the Sacramento valley and worked on several hundred cars & engines over that time. I only recall a few dropped valve heads like Dave & Mark photographed. While cars don't pull the same power demands as do airplanes, they do run at very high temps in the central California valley. Both of the shop owners were insistent upon one premise; any cylinder head that came apart for a valve job always got new exhaust valves. We'd turn the intakes valves & reuse those but we always installed new exhaust valves. If the customers allowed it, we recommended and installed stainless valves.
I'm not sure what I'm seeing in Dave's photo. If that is a valve in the right side combustion chamber, I've never seen one with shouldered head faced onto a stem. The stem sure looks burned. John Bouyea N5391M/ KR2 OR81/ Hillsboro, OR
