Engine 2.0 (Chery Fora, A21). Manual — part 6

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

21

See the following picture for removal sequence of intake and exhaust camshaft-bearing caps:

8) Take out the camshaft and the hydraulic tappet.

9) Remove the valve spring with special tools.

(Picture is unavailable)

10) Remove the used valve oil seal with special tools.

(Picture is unavailable)

2.2.3

Inspection

1)

Check the valve spring.

Measure the free length, the verticality and
the length under special pressure with caliper.

Standard

Value(mm)

Free length

47.7

Length of

620N

32

Replace with the new valve spring if the
measured value exceeds the limit value.

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

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2) Check

camshaft

Measure the camshaft diameter with
micrometer caliper.

Standard Value

（mm）

Limit Value

(mm)

Diameter

￠24

-0.053

-0.040

Replace with the new camshaft if the
measured value exceeds the limit value.

3) Examine

camshaft

Measure the high of cam with micrometer
caliper.

Standard Value

（mm）

limit value

（mm）

Intake

Cam

37.15

Exhaust

Cam

37.05

Replace with the new camshaft if the
measured value exceeds the limit value.

4) Examine diameter of valve stem

a: Measure the diameter of valve stem with

micrometer caliper.

See the picture for measuring points: they are
26, 52, and 78 mm from measure positions to
bottom of valve.

Valve

Guide

External Diameter

Of Valve Stem

Internal Diameter

Of Valve Guide

Measuring Point

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

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b:

Use internal micrometer guage to
measure the internal diameter of valve
guide and the measuring point is a
quartering point of guide.

c:

Calculate the difference of measured
value and the clearance.

Replace the valve or the guide if the value
exceeds the limit value.

d:

Examine the contact bandwidth of
valve.

e:

Check the valve seat insert.

Measuring Point

Contact Position (Should be

the Center of Slope)

Edge

Thickness

CHERY A21 SERVICE MANUAL

MECHANISM OF 2.0NALC ENGINE

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Standard

Value

Outer Diameter

of Valve stem

(mm)

IN

￠5.98±0.008

EX

￠5.96±0.008

Inner Diameter

of Valve guide

(mm)

IN

￠5.4±0.1

EX

￠5.4±0.1

Clearance

(mm)

IN

0.02

EX

0.04

Thickness of

Valve Top

（mm）

IN

0.3±0.15

EX

0.3±0.15

Seal Bandwidth

（mm）

IN 1.158

EX 1.306