Doosan DX60R Shop Manual page 294

Inspection of Valve Guides
Valve Guide Inside Diameter
Visually inspect the valve guides for distortions, scoring or other
damage.
NOTE: Measure the valve guides while they are installed in
cylinder head.
Use a telescoping gauge and micrometer to measure the inside
diameter at each end of the valve guide. Measure in three
places and 90° apart (Figure 137). See "Intake / Exhaust Valve
and Guide" on page -95 for the service limit. Replace the valve
guides if not within specification.
Inspection of Cylinder Head
Cylinder Head Distortion
Place the cylinder head flat and inverted (combustion side up)
on the bench. Use a straight edge and feeler gauge to measure
cylinder head distortion (Figure 138). Measure diagonally and
along each side. See "Cylinder Head" on page -95 for the
service limit.
If distortion exceeds the service limit, resurface or replace the
cylinder head. Remove only enough material to make the
cylinder head flat, but do not remove more than 0.008 in (0.20
mm).
Inspection of Intake and Exhaust Valves
Visually inspect the intake and exhaust valves. Replace any
valves that are obviously discolored, heavily pitted or otherwise
damaged.
Valve Stem Diameter
Use a micrometer to measure the valve stem diameter.
Measure the valve stem near the combustion end and near the
opposite end (1, Figure 139). See "Intake / Exhaust Valve and
Guide" on page -95 for the service limit.
Engine
Page 114
Figure 137
Figure 138
Figure 139
FG008888
1
FG008889
SP001693