Chery S11 / Chery QQ. Manual — part 119

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

45

4.2.4 Measure the diameter of the piston

4.2.4.1

Measure at about 11 mm to the bottom of the

piston, along the direction vertical to the piston pin.

Standard value:

72

013

.

0

025

.

0

φ

-

-

4.2.5 Inspect the clearance between the piston ring and

the ring gloove

4.2.5.1

Measure around the ring gloove with a piston

ring and a feeler gauge

Standard value

(mm)

Limit

(mm)

First ring

0.03~0.06

0.12

Second

ring

0.03~0.06

0.11

4.2.6

Inspect the end clearance of piston ring

4.2.6.1

Put the piston ring 45mm below the top surface

of the cylinder hole. Press down the piston ring with the

piston head, and then measure the opening with a feeler

gauge.

Standard value

(mm)

Limit

(mm)

First ring

0.25-0.40

0.65

Second

ring

0.35~0.50

0.65

Oil ring

0.20~0.70

1.00

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

46

4.2.7

Inspect the clearance between the piston and

cylinder wall

4.2.7.1

Measure the inner diameter of the cylinder and

the outer diameter of the piston at the positions as

indicated in the right figure. If the measurement results

exceed the limit, replace the piston or cylinder.

Standard value: 0.018～0.030

Limit:

0.10

[Reference] The clearance between the piston and cylinder

bore is controlled by the difference between the minimum

inside diameter of piston hole and the maximum outer

diameter of piston.

4.2.7.2

After replacing the piston or the cylinder body,

confirm the clearance again

Standard value: 0.018～0.030

4.3 Crankshaft

4.3.1 Inspect the proper alignment of the main axle

diameter.

4.3.1.1

Measure the proper alignment with a dial gauge,

if the proper alignment is beyond the limit, replace the

crankshaft.

Limit:

0.03mm

Notice: The bending value should be equal to

one-second the run-out value of crankshaft rotating one

circle.

4.3.2

Inspect the crankshaft for the abrasion.

4.3.2.1

Measure the connecting rod journal at the

positions indicated in the left figure with a microcaliper,

and figure out the roundness and cylindricity.

Limit:

0.005mm

4.3.2.2

Measure the connecting rod journal at the

positions indicated in the right figure with a microcaliper,

and figure out the roundness and cylindricity.

Limit:

0.004mm

5 Assembly of Crank Connecting Rod

mechanism

5.1 Assembly of the piston connecting rod

Measurement position of piston

Outer Diameter

Measurement

position of piston

Inner Diameter

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

47

5.1.1

Assemble the piston, connecting rod and the

piston pin with special tool following the instructions

below:

5.1.1.1

Spread engine oil over the pin hole of the

connecting rod, assemble according to the group mark and

direction mark of piston and connecting rod.

5.1.1.2

Assemble the piston and the connecting rod with

special tools shown in the right figure.

5.1.1.3

Adjust and assemble the piston and connecting

rod as indicated in the right figure. Spread the piston pin

with oil and then assemble the piston and connecting rod

with a oressing machine.

Notice: When pressing in the piston pin, make sure the

fitting direction is correct.

·When the piston pin is pressed into the piston, the

small end of the connecting rod should be heated

to 300

, and the pin should be aligned properly.

℃

5.2 Install the first and second pistion ring and the oil ring

according to the following instruction:

5.2.1 Installation of piston ring

Make the side with marks face upwards, and then fix it

with piston pin tools.

5.2.2

Mount the steel tape combined oil ring (bushing

ring lower, lower blade, upper blade) firstly, and then

mount the second gas ring, and finally mount the first gas

ring. Opening angles of rings are shown in the figure:

0

Mark Forward

Align and Straight

Mark

1

st

Ring

2nd Ring

Oil Ring

Lower Blade

1

st

Ring

2nd Ring

Front

Bushing

Ring

Rear

Upper Blade

Section Shape

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

48

5.3 Resemble the crankshaft main bearing cap,

crankshaft, crankshaft bearing bushing and the crankshaft

axial thrust plate, pay attention to the following:

5.3.1 Assembling the bearing bushing, its raised thrust

block should fit into the locating groove in the cylinder

body.

Notice: The bearing bushing is from the same

manufacturer.

5.3.2 Spread the crankshaft bearing bushing (upper

piece) with oil before assemble the crankshaft

5.3.3 Mount the thrust plate on the cylinder body bearing

base and make sure that the side with oil gloove

(crankshaft shank) face outwards.

Notice: Spread the side of oil glove with oil

5.3.4 Fix the crankshaft bearing bushing (lower piece) in

the bearing cap, the bearing bushing should fit into the

thrust groove.

5.3.5 Spread engine oil over the friction surface of

crankshaft bearing bushing (lower piece), assemble the

bushing according to the mark forwards in the main

bearing cap of the crankshaft.

5.3.6 Spread oil over the bolts, within three or two times,

tighten them with specified torque.

Torque: 70±3.5N.m

5.3.7 Rotate the crankshaft after assembly, it should

rotates swiftly, the rotating torque should be less than

1Nm.

Thrust Plate

Oil Tank

Spread Oil on the surface of

Bearing Bushing

Outer Forward of Oil

Tank

Forward Mark

Axle Diameter Mark