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13.Cylinder Block and Piston
Preparing documents-----------------13.1 Piston---------------------------13.4
Failure diagnosis --------------------13.2 Piston installation-------------13.5
Cylinder block-----------------------13.3
13.1 Preparing documents
Work Instructions
All parts shall be cleaned and blown by high pressure air before check.
Function of the cylinder block:
cylinder block provides space for gas compression, combustion and expansion,
and also guides piston movement.
It also transfers part of heat energy in the cylinder to cooling medium around.
Function of the piston:
Piston bears pressure arising from mixed gas combustion inside the cylinder and transfers such pressure to the
connecting rod for driving the crankshaft.
It forms combustion chamber along with the cylinder cover.
It acts as slide valve for air inlet/stop, periodically compresses fresh mixed gas from the crankcase into the cylinder
and discharges exhaust gas after combustion in the cylinder.
Preparing Principles
Unit: mm
Item
Standard
Limit for use
Inner diameter
37-37.01
37.01
Bending
-
-
Cylindricity
0.005
0.005
Flatness 0.03
0.03
Cylinder
Roundness
-
-
Top ring
0.02-0.06
0.06
Piston ring groove gap
Ring 2
0.02-0.06
0.06
Top ring
0.1-0.25
0.25
Joint gap
Ring 2
0.1-0.25
0.25
Outer diameter of piston
36.975-36.985
36.975
Clearance between piston and cylinder
0.02-0.03
0.03
Piston
Piston
ring
Inner diameter of piston pin hole
10.002-10.008
10.008
Outer diameter of piston ring
9.994-10
9.994
Clearance between piston pin hole and piston pin
0.002-0.014
0.014
Inner diameter of the smaller end of the connecting rod
14.995-15.006 10.018
