Chery Fora (Elara A520). Manual — part 165

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

33

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

34

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.

Note: Do not rotate the crankshaft during the
process.

Standard Value

Diameter

9

.

47

0

016

.

0

−

Roundness

——

Cylindricity

——

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

35

Loosen the connecting rod bolt, remove the
cap, and measure the maximum width of
pressed clearance gauge with the ruler on its
package to get the clearance value.

Replace with the new connecting rod bearing
if the examined clearance exceeds the limit.

Note: Use the same brand consistent with
assorting sign when you replace the bearing
bushing.

Standard

Value

Abrasion

Limit

Clearance 0.016—0.051

Selection of connecting rod bearing:

You may select the connecting rod bearing by
observing the sign on the first balance weight
at the front end of crankshaft.

（see picture,

unavailable）

6)

Inspect the planeness of cylinder block
surface.

a:

Clean the upper surface of cylinder
block.

b:

Check with ruler and feeler gauge
whether the surface of cylinder block is
warped. (Measure it in the sequence of
A, C, D, E, F, G in the picture)

C:

Revise it if the warping amount is
excessive.

Replace with the new cylinder if it exceeds
the limit. The maximum for the sum of
permitted abrading thickness of cylinder
block and cylinder head is:

Standard Value

limit

value

warping

amount

0.04

Clearance Gauge of Plastic

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

36

7)

Inspect cylinder

a:

Inspect if the cylinder wall is scratched
or scored.

If there are cylinder scoring

and scratching you need to hone cylinder
wall, replace cylinder liner or replace
cylinder block.

b:

Examine

the

inner

diameter

and

cylindricity of cylinder with cylinder
gauge.

Standard value

Inner diameter

83.5

cylindricity

0.008

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;

3.2.3 Installation

1)

Spread oil on the piston pin and in the
piston pin hole, connect the piston and
connecting rod with piston pin, and
mount the piston pin circlip.

2)

Mount the piston ring. Mount the rings
on the piston in the sequence of oil ring
expander, upper and lower segments, 2nd
air ring and 1st air ring; Pay attention to
the direction of piston ring, the side with
“

TOP

” should be upward. The two

segments and expander are staggered.
The angle of expander connector points
to the top of piston, and the 1st ring and
2nd ring form

120°

with the upper

expander.

12 mm

Center

Bottom

The Openings Of Rings Form

120°With Each Other.