XIII Cylinder Block and Piston
Preparatory data------------13.1 Piston---------------------- 13.4
Fault diagnosis--------------13.2 Cylinder installation-----13.5
Cylinder block--------------13.3
13.1 Preparatory Data
Precautions on Operation
All the components shall be cleaned before inspection and test, and purged with high-pressure air.
Function of cylinder block: Cylinder block provides the space for gas compression, combustion
and expansion and guides piston movement. It also transfers part of heat in the cylinder to
surrounding coolant.
Function of piston:
Piston can bear the pressure generated by combustion of mixed combustible gas in the cylinder and transmit the
pressure to connecting rod to drive crankshaft to rotate.
It forms a combustion chamber with cylinder head.
It works as a slide valve to compress regularly fresh mixed gas from crankcase into cylinder and exhaust combustion
gas from the cylinder.
Basic data Unit
：
mm
Item Standard
Value Service
Limit
Cylinder
ID 57-57.01
57.10
Cylindricity 0.005
0.05
Roundness 0.004
0.05
Flatness 0.02
0.05
Piston OD(measuring point)
56.987-56.977
(8 mm at the bottom of piston skirt)
56.93
Piston pin hole ID
14.002-14.008
14.04
Piston pin OD
13.994-13.997
13.96
Clearance between piston and piston pin
0.005-0.014
0.05
Clearance between piston ring and ring groove
Top ring
0.020-0.060
Second ring
0.020-0.060
Joint clearance of piston rings
Top ring
0.25-0.35
Second ring
0.20-0.35
Oil ring
0.20-0.70
Connecting rod small end ID
14.010-14.018
14.06
Clearance between linkage rod and piston pin
0.013-0.024
0.10