2. Measure the distance between the end of the valve stem and the top edge of the cylinder head (pic. 4.25).
3. Calculate the maximum allowable lapping distance.
- Minimum distance for inlet valve: 33.8 mm.
- Minimum distance for exhaust valve: 34.1 mm.
4. Measured distance - minimum distance = maximum allowable lapping distance. For example, Measured distance 35.1 mm - minimum distance 34.1 mm = maximum allowable lapping distance 1.0 mm.
The inlet valve seat angles are shown in fig. 5.26, exhaust valve - in fig. 5.27.
Inlet valve seat angles
Diameter a: 1F and ADZ engines - 37.2 mm; AFT engine - 39.2 mm
Diameter b: maximum allowable lapping distance.
c = max. 2.0 mm.
Z = Bottom edge of cylinder head.
Valve seat angle α = 45°.
Upper correction angle β = 30°.
Lower correction angle γ = 60°.
Exhaust valve seat angles
Diameter a = 32.4 mm.
Diameter b: maximum allowable lapping distance.
c = max. 2.0 mm.
Z = Bottom edge of cylinder head.
Valve seat angle α = 45°.
Upper correction angle β = 30°.
Lower correction angle γ = 60°.
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