Doosan DX22 - Inspecting the Cylinder Head

10. Cylinder Block/Head
140
Inspecting the Cylinder Head
1. Inspecting the Cylinder Head
1) Remove carbon residue from the bottom of the cylinder
head.
2) Check the cylinder head visually for damage.
3) Perform a hydrostatic test or magnetic particle test to
check for small cracks or damage that cannot be identi-
fied with the naked eye.
2. Bottom distortion
1) Measure the distortion of the cylinder head in six direc-
tions with a straightedge and feeler gauge.
EH6OM028
2) If the measured result exceeds the allowable service
limit, correct it using fine sandpaper or a grinder.
3) If the measurement exceeds the allowable limit, replace
the cylinder head.
• Cylinder head distortion and height
3. Flatness
1) Measure the flatness of the intake/exhaust manifold
mounting surface of the cylinder head with a straightedge
and feeler gauge.
EH6OM029
4. Flatness
1) The hydrostatic test for the cylinder head is performed in
the same way as the test for the cylinder block.
CAUTION
Be careful not to scratch the valve seat surface.
Make sure to keep bolts free of oil.
Wipe any oil off bolts before using them.
Reference value
Allowable
limit
Flatness of bottom
surface of cylinder
head
0.015 mm
(0.00059 in.) or less
0.03 mm
(0.00118 in.)
Head height: t
116.95~117.05 mm
(4.604 ~ 4.608 in.)
116.5 mm
(4.587 in.)
(t)
A
B
E
F
D
C
Reference value Allowable limit
0.015 mm (0.00059 in.) or
less
0.03 mm (0.00118 in.)