Mitsubishi S12A2, Service Manual

Page: 108 / 354

6-4
Chapter 6 INSPECTION AND REPAIR OF BASIC ENGINE
1.3 Valve Stem Outside Diameter and Valve Guide Inside Diameter - Measure
Measure the outside diameter of valve stem and the inside
diameter of valve guide at the top and bottom sliding ends in
right-angle directions as shown, as the sliding surface tends
to wear at the top and bottom ends.If the measurement
exceeds the limit, replace the valve guide or valve with a
new one.
Note: Lap the valve and valve seat whenever new valve is in-
stalled.
Valve Stem Outside Diameter - Measure
Valve Guide Inside Diameter - Measure
1.4 Valve Guide - Replace
(1)
Remove the valve guide with valve guide remover.
Valve Guide - Remove
(2)
With guide and seal installer, press-in the new valve
guide slowly.
Valve Guide - Press-In
Item
Nominal
value
Standard
value
Limit value
Valve stem
outside diam-
eter
Inlet
ø10 mm
[0.39 in.]
9.940 to
9.960 mm
[0.0010 to
0.0044 in.]
9.910 mm
[0.3902 in.]
Exhaust
ø10 mm
[0.39 in.]
9.910 to
9.930 mm
[0.3902 to
0.3909 in.]
9.880 mm
[0.3890 in.]
Valve guide inside diam-
eter ø10 mm
[0.39 in.]
10.000 to
10.015 mm
[0.3937 to
0.3943 in.]
10.060 mm
[0.3961 in.]
Measurement
direction
Measurement
point
Measurement
direction
Measurement
point
Be sure to use the guide and seal installer, and press-
in the valve guide to the specified height.
Valve guide
remover
P/N:36291-04200
Guide & seal installer
P/N:32591-10300
Valve guide
Cylinder head
27.5 27.5 ± 0.1 ± 0.1 mm mm
[1.083 [1.083 ± 0.004 in.] 0.004 in.]
27.5 ± 0.1 mm
[1.083 ± 0.004 in.]