Check the end face of each valve stem for wear. This face meets
the rocker arm intermittently in operation, and might become
concaved or otherwise irregular. As necessary, smoothen the
end face with an oil stone and, if this grinding removes the end
stock by as much as 0.5 mm (0.0196 in.) (as measured from the
original face), replace the valve.
Check each valve for radial runout with a dial gauge and “V”
block. The object of this check is to determine whether the valve
stem is true and square relative to the head.
If the limit is exceeded, do not attempt to correct the stem; re-
place the valve, instead.
Valve seats
Seating contact width:
Produce a contact pattern on each valve in the usual manner,
namely, by giving a uniform coat of marking compound (Red-
lead paste) to the valve seat and by rotatingly tapping the seat
with the valve head. The valve lapper (the tool used in valve lap-
ping) must be used.
The pattern produced on the seating face of the valve must be
a continuous ring without any break, and the width “a” of the pat-
tern must be within the stated range.
CAUTION:
The valves to be checked and serviced for seating width
and contact pattern must be those found satisfactory in
regard to stem clearance in the guide and also the re-
quirements stated in the preceding part titled VALVES.
6A-22
ENGINE MECHANICAL (F8B ENGINE)
Limit on stock allowance of
valve stem end face
0.5 mm (0.0196 in.)
Limit on valve head radial
runout
0.08 mm (0.0031 in.)
“a”
Standard seating width
revealed by contact pat-
Intake
1.3 – 1.5 mm
“a”
revealed by contact at-
tern on valve face
Exhaust
(0.05 – 0.06 in.)
