Measuring Push Rod Runout; Measuring Valve Stem Outside Diameter And Valve Guide Inside Diameter; Replacing Valve Guide - Mitsubishi Heavy Industries SL Series Service Manual

1.4 Measuring push rod runout

Measure the runout of push rod. If the standard value is
exceeded, replace the push rod.
Item Standard
Push rod 0.3 mm
runout [0.012 in.] or less
1.5 Measuring valve stem outside diameter and
valve guide inside diameter
Measure the diameter at the top and bottom ends at right
angles to the outer and inner surfaces, since valve stems and
valve guides are more likely to wear at both ends. If the
outside diameter is less than the limit, or the clearance
exceeds the limit, replace either the valve or the valve guide
with a new one.
Item Nominal
ø 6.6 mm
Inlet
Valve
[0.260 in.]
stem outside
ø 6.6 mm
diameter
Exhaust
[0.260 in.]
Clearance
Inlet -
between
valve stem
and valve
Exhaust -
guide
Valve guide mounting 10 mm
dimension [0.39 in.]

1.6 Replacing valve guide

(1) Remove the valve guide with a punching tool pressing
from the cylinder head bottom surface.
(2) When press-fitting the new valve guide, press-fit the
valve guide with a press from the cylinder head top
surface.
(3) After press-fitting the valve guide, insert the valve and
check the movement.
(4) When replacing the valve with new one, check the
contact between the valve and the valve seat.
Remark
Total indicated reading
(TIR)
Standard Limit
6.565 to 6.580 mm 6.500 mm
[0.2585 to 0.2591 in.] [0.2559 in.]
6.530 to 6.550 mm 6.500 mm
[0.2571 to 0.2579 in.] [0.2559 in.]
0.020 to 0.050 mm 0.100 mm
[0.0008 to 0.0020 in.] [0.0039 in]
0.050 to 0.085 mm 0.150 mm
[0.0020 to 0.0033 in.] [0.0059 in.]
9.5 to 10.5 mm
-
[0.374 to 0.413 in.]
INSPECTION AND REPAIR OF BASIC ENGINE
1/2
Measuring push rod runout
Measuring valve stem outside diameter
Inside
micrometer
Measuring valve guide inside diameter
Valve guide
Cylinderhead
Replacing valve guide
Push rod
1/2
Measuring
directions
Measuring
points
Measuring
directions
Measuring
points
6-3