Yuchai YC4D60-D21 - Main parts fit clearances

12
Main parts fit clearances
No.
Description
Prescribed dimensions (mm)
Type of fit
Assembly
tolerance (mm)
1
Exhaust valve seat
insert/exhaust valve
Φ44.5
025.0
0

/Φ44.5
095.0
070.0


interference
0.045～0.095
2
Intake valve seat
insert/exhaust seat
Φ48.5
025.0
0

/Φ48.5
139.0
114.0


interference
0.089～0.139
3
Valve guide/cylinder
head valve guide hole
Φ16
018.0
0

/Φ16
046.0
028.0


interference
0.010～0.046
4
Valve guide/exhaust
valve stem
Φ9.5
019.0
0

/Φ9.5
04.0
062.0


radial
clearance
0.040～0.081
5
Valve guide/intake
valve stem
Φ9.5
019.0
0

/Φ9.5
025.0
047.0


radial
clearance
0.025～0.066
6
Rocker arm bush/
rocker arm shaft
Φ25
021.0
0

/Φ25
02.0
041.0


radial
clearance
0.020±0.062
7
Cylinder
bore/diameter of the
lower part of the
piston skirt
Φ108
022.0
0

/Φ107.86±0.01
radial
clearance
0.130～0.172
8
Valve tappet/cylinder
block tappet hole
Φ28
052.0
0

/Φ28
02.0
041.0


radial
clearance
0.020～0.093