Porsche 912 E - Page 54

. 0 .
Machining 45 Surface
Remove a minimum of base material~ Conse-
quently the
work must be stopped as soon as the
whole seat surface has been
machined.
Machining 75° Surface
Chamfer bottom edge
of exhaust valve seat
insert slightly.
Printed in Germany
Engine, Cylinder Head, Valves
15
Machining 15° Surface
Machine the upper edge
of the valve seat insert
until
the specified seat width is reached.
Refacing Valve Seats