MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
152
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 4-3-11 Measuring the edge thickness of
valve head
Fig. 4-3-12 Measuring the valve seat contact
taper face angle
Fig. 4-3-13 Measuring the valve sinkage
3.2 Checking the thickness of valve
(1) Measure the edge thickness of valve head. See Fig.
4-3-11.
(2) Replace the valve and valve guide in pairs if the
measured value is below the limitation.
The standard value of valve thickness
Intake valve
1.99 mm±0.10 mm
Exhaust valve
2.10±0.10 mm
3.3 Checking the valve seat contact taper face angle
(1) Measure the valve seat contact taper face angle.
See Fig. 4-3-12.
(2) Replace the valve, valve guide and valve seat in
group if the measured value is above the limitation.
The standard value of valve seat contact taper face
angle on the valve
44°45’ ±75’
3.4 Checking the valve sinkage
(1) Install the valve
①
onto the cylinder head
②
. See
Fig. 4-3-13.
(2) Measure the valve sinkage from the bottom surface
of cylinder head with a depth gage or a ruler and a steel
ruler. See Fig. 4-3-13.
(3) Replace the valve set if any measured valve of
sinkage is above the limitation.
The valves of sinkage
Valve
Standard
Limitation
Intake valve
0.73 mm
1.28 mm
Exhaust valve
0.70 mm
1.20 mm
