Chery Fora (Elara A520). Manual — part 58

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

35

7) Uplift the connecting rod and the piston

with a wooden stem and then remove
the connecting rod and piston assembly.

8) Remove the piston ring.

9) Remove the retainer ring of piston pin

and draw out the piston pin.

Note: With large tension, the retainer ring
may hurt people in the process of removal.

3.2.2 Inspection

I. Check

piston

1) Examine the diameter of piston.

Measure the diameter along the vertical
direction to piston pin and at the place 11mm
under piston skirt with micrometer caliper.

Cylinder No.

Standard Size

1

83.46±0.009

2

83.46±0.009

3

83.46±0.009

4

83.46±0.009

Replace with the new one if the part cannot
be worn and torn any longer.

Retainer Ring

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

36

2) Examine the clearance between piston

ring and ring groove.

a. Clean up the accumulated carbon in the

ring groove with piston ring.

b. Examine the clearance between piston

ring and ring groove with feeler gauge.

Reference Value

（mm）

1

st

Ring

0.04--0.08

2

nd

Ring

0.01--0.025

Replace with the new one if the examined
clearance cannot be worn and torn any
longer.

3) Inspect the end clearance of piston ring.

a. Put the piston ring at the position 45mm

below the top surface of cylinder
aperture and push the piston ring into
cylinder with piston.

b. Measure the opening with feeler gauge.

Replace with the new piston if the examined
clearance exceeds the limit.

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

37

4)

Inspect the diameter of piston pin and
piston pin hole.

a. As the following picture, measure the

piston pin position around with
micrometer caliper. And take the
maximum value as the diameter of
piston pin.

b. Measure the diameter of piston pin hole

around with micrometer guage for
inside diameter, as the following picture,
and take the minimum value as the
diameter of pin hole.

Replace with the new piston and pin if the
examined clearance exceeds the limit.

Standard

Size

Diameter of piston pin

21

0

005

.

0

−

Diameter of piston pin

hole

21

008

.

0

002

.

0

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

38

5)

Inspect the connecting rod journal and
connecting rod bearing

a.

Examine the diameter of connecting rod
journal.

Measure the axle diameter of connecting rod
with micrometer caliper.

Rotate the crankshaft 90° and measure it
again.

Work out the Roundness and cylindricity
through twice measuring.

①

Roundness=Max. diameter

— Min.

diameter /2 as the picture, take the
vertical diameters on the same plane,
subtract the half of Minimum from the
Maximum to get roundness.

②

cylindricity= Maximum bore

－

Minimum bore/2 As the picture,
measure the bores of 3 planes along
both A direction and B direction
respectively. Get the maximum and the
minimum from 6 values, and then
subtract the half of Minimum from the
Maximum to get cylindricity;

b.

Inspect the radial clearance of
connecting rod bearing

Inspect the radial clearance of connecting rod
bearing with clearance gauge. Clean up the
connecting rod journal and connecting rod
bearing. And put clearance gauge on the
journal, fasten bearing bushing and fasten the
bolt according to set torque.

Standard

Value

Diameter

9

.

47

0

016

.

0

−

Roundness

——

Cylindricity

——