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

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