<VV> Dropped Valve Seats

[Smitty]

Smitty says;  For what it is worth I'd like to make a comment on valve
seats.  There may have been some that dropped valve seats after getting an
engine hot on the uphill and then cooling going down the other side.  I know
of no incidents like that, first hand.  The ones I know of happened like
this.  1- Owner of a 140 on a warm day convertible cruise in town stopped
for an ice cream.  Came out and started the engine, and a seat fell out.  2-
Car in restoration for 2 years, initially started and allowed to idle for 20
minutes to quiet lifters.  68 95 hp.  Shortly after lifters pumped up, seat
fell out.  3-Restoration project engine being used to move car in and out of
garage. 64 95 hp.  During one of maybe 10 such moves, seat fell out.  4-Hard
working, camper hauling, Late 95 hp in flat country left idling to warm up
engine on a cold morning.  After 5 minutes, seat fell out.  5-Late 110hp,
(also a camper hauller in flat country), left idling to charge camper
battery.  15 minutes later a seat fell out.  6-The jury is still out on this
one because the seat went back in the hole and the owner refuses to believe
there is anything wrong.  I40 hp. Car was in a parade.  Seat fell out as
parade was over.

Three of those were mine.  I realize that I am only one person and am
limited to my knowledge of events in my 43 years of playing with Corvairs,
but those experiences indicate to me that most valve seats fall out at low
rpm and in non stressful conditions.  Not going down the back side of the
mountain.  

If I have to drive a car which has to be handled with kid gloves under
certain conditions, I don't think I will be driving it long.