Chery A series. Instruction - page 14
PISTON AND CONNECTING ROD ASSEMBLY
PISTON REMOVAL, MEASURE AND INSTALLATION
Removal
Rotate the crank shaft to the bottom dead
center (BDC) of the removed cylinder, check
whether there is a cylinder number on the
connecting rod body and cap, which shall be
on the left of the rod (seeing from the front).
If there is no such a number, number each
cylinder before removal.
Remove the connecting rod bolts to dismantle
the connecting rod cap, take the
connecting-rod bearing shell out and label the
cylinder number and bottom and top shell on
the back of the shell.
Push the connecting rod and piston out from
the cylinder block with a wooden club and
take the cylinder rod out.
Remove the piston ring with a special tool or
the leaf of a clearance gauge and label each
cylinder and bottom and top leaf.
Press the piston pin out of the piston and the
small end of the connecting rod with a press
machine and put the piston, piston ring and
pin of each cylinder together.
B-33
Rinsing and inspection
Rinse and clean the carbon deposit on the
piston, piston ring and pin.
Rinse and clean the carbon deposit on the
bottom of the cylinder bore.
Measure the diameter of the cylinder bore.
480 M cylinder bore (unit: mm)
480 E cylinder bore (unit: mm)
1 79.94-79.95
1
79.94-79.95
2 79.95-79.96
2
79.95-79.96
3 79.96-79.97
3
79.96-79.97
Ex-factory
grouping
4 79.97-79.98
4
79.97-79.98
A 80.23-80.24
A
80.23-80.24
B 80.24-80.25
B
80.24-80.25
Ex-factory
repair
C 80.25-80.26 C 80.25-80.26
Standard 79.965-77.975 Standard 79.965-77.975
Oversized by 0.29
80.245-80.255
Oversized by 0.29
80.245-80.255
For
Maintenance
Oversized by 0.5
80.466-80.475
Oversized by 0.5
80.466-80.475
Grind the cylinder bore according to the size for
maintenance with the grinding angle to be 50°
~60°.
Measure the piston from the point that is 19mm
away from the bottom of the skirt.
B-34
Diameter of 480M piston skirt
(unit: mm)
Diameter of 480E
piston skirt (unit: mm)
Diameter of UAES’s
new two-valve piston
skirt (unit: mm)
1 79.91-79.92
79.915-79.925
79.915-79.925
2 79.92-79.93
79.925-79.935
79.925-79.935
3 79.93-79.94
79.935-79.94
79.935-79.94
Ex-factory
grouping
4 79.94-79.95
79.945-79.955
79.945-79.955
A 80.20-80.21
80.205-80.215
80.205-80.215
B 80.21-80.22
80.215-80.225
80.215-80.225
Ex-factory
repair
C 80.22-80.23
80.225-80.235
80.225-80.235
Standard 79.93-79.955
79.965-79.975
Oversized by 0.29
80.21-80.235
80.245-80.255
Spare
parts
Oversized by 0.5
80.43-80.455
80.465-80.475
80.435-80.455
Measure the diameter of piston pin bore
Diameter of 480M piston pin bore (unit: mm)
Diameter of 480E piston pin bore (unit: mm)
White 20.630-20.633
White
20.630-20.633
Red 20.633-20.636
Red
20.633-20.636
Blue 20.636-20.639
Blue
20.636-20.639
Measure the diameter of the piston pin
Diameter of 480M piston pin bore (unit: mm)
Diameter of 480E piston pin bore (unit: mm)
White 20.622-20.625 White 20.622-20.625
Red 20.625-20.628 Red 20.625-20.628
Blue 20.628-20.631 Blue 20.628-20.631
Measure the end clearance of the piston
ring
First compression ring: 0.30-0.50mm
Second compression ring: 0.30-0.50mm
Oil ring: 0.40-1.40mm
B-35
Measure the axial clearance of piston ring in the piston groove
Height of the piston
ring (unit: mm)
Size of piston ring
groove (unit: mm)
Fit clearance
(unit: mm)
First compression ring
1.60 1.6
0.050-0.082
Second compression
ring
2.0 2.0
0.050-0.082
0.61±0.025
Sealing strip of oil ring
Spring of oil ring
2.68±0.05
4.0
0.01-0.23
Cast iron oil ring
4.0 4.0
0.025-0.055
480 UAES’s new two-valve
Height of the piston ring
(unit: mm)
Size of piston ring groove
(unit: mm)
First compression
ring
1.2(-0.03~-0.01) 1.2(0.03~0.05)
Second
compression ring
1.5(-0.03~-0.01) 1.5(0.02~0.04)
0.46±0.02
Sealing strip of
oil ring
Spring of oil ring
2.75±0.05
2.0±0.02
3(0.01~0.03)
Measure the small-end bore diameter of the
connecting rodΦ20.589
Check whether the big-end injection hole of the
connecting rod is blocked, with the outlet
diameter to be Φ1mm.
+0.06
+0.04
+0.06
+0.04
+0.03
+0.01
+0.03
+0.01
-0.015
-0.025
0
-0.012
0
-0 012
B-36