Man D 2842 LE 620 Repair Manual page 100

Fig. 8
When reworking the valve seat inserts, remove as
little material as possible from the seat face.
The valve recess serves as the reference value.
Fig. 9
The valve seat insert must be changed if as a re-
sult of the cylinder head interface and the valve
seat insert having been machined the theoretical
valve seat is too deep in the cylinder head or the
seat face has become too wide.
Ensure that the valve recess (X) is correct, see
"Service Data".
Reworking valve seat
8
9
98
x