Mitsubishi Heavy Industries S4S, Service Manual

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INSPECTION AND REPAIR OF BASIC ENGINE
6-8
1.10 Measuring distortion of the bottom surface
of the cylinder head
&$87,21
Refacing of cylinder head should be kept to an abso-
lute minimum.
Excessive grinding of the cylinder head may result in
defects such as defective combustion and stamping
(contact between piston and valve).
With a straight edge placed on the bottom face of the
cylinder head, measure the bottom face distortion using a
feeler gauge. If the measurement exceeds the limit, grind the
bottom face using a surface grinder.
Note: Do not grind the surfaces more than 0.2 mm [0.008
in.] in total (cylinder head bottom surface plus
crankcase top surface).
Measuring distortion of the bottom surface of the
cylinder head
1.11 Measuring pushrod runout
Measure the runout of each pushrod. Replace if the limit is
exceeded.
Measuring pushrod runout
Item Standard Limit
Distortion of bot-
tom face 0.05 mm
[0.0020 in.] or less
0.20 mm
[0.0079 in.]
Item Standard Limit Remark
Pushrod
runout 0.6 mm
[0.024 in.] or less
0.6 mm
[0.024 in.]
Total indicated reading
(TIR)
1/2 1/2
Push rod