Chpter IV Mechanical System
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
183
Fig. 4-5-14 Measurement for the clearance
between the piston ring and the piston ring
groove with a feeler gauge
Fig. 4-5-15 Measurement for piston pin outer
diameter
Fig. 4-5-16 Measurement for inner diameter
of connecting rod small end hole
2.2 Checking the axial clearance between the piston
ring and the piston ring groove
Use a feeler gauge to measure the axial clearance
between the piston ring and the piston ring groove. See
Fig. 4-5-14.
Replace the piston if the axial clearance exceeds the
limitation.
Axial clearance between the piston ring and the piston
ring groove
Piston ring
Standard
Compression
ring
First compression
ring
0.055~0.100mm
Second
compression ring
0.035~0.080mm
Oil ring
0.030~0.070mm
3. Piston
Visually check the piston pin for crack, bruise or other
damage, and replace it if necessary.
3.1 Checking the piston pin outer diameter
Use a screw micrometer to measure the piston pin outer
diameter at three different positions in two directions.
See Fig. 4-5-15.
Replace the piston pin if the measured value exceeds
the limitation.
Piston pin outer diameter
Standard
28.007~28.010mm
3.2 Checking the inner diameter of connecting rod
small end hole
Use an inside dial indicator to measure the inner
diameter of the connecting rod small end hole. See Fig.
4-5-16.
Replace the connecting rod/bushing and the piston pin
if the clearance between the connecting rod small end
hole and the piston pin is not in accordance with the
specified value.
Clearance between the connecting rod small end hole
and the piston pin
Standard
0.010~0.024mm
