Chery A18. Manual — part 36

Installation
Before installation, tap the threaded hole on
the cylinder block with tapping drill,
especially those of the cylinder head bolts and
main bearing bolts.

Cylinder head bolt: M10X1.5~6H

Main bearing bolt: M12X1.75~6H

Installation of the whiney key of the crank
shaft: gently drive the whiney key into the key
slot. The clearance between the whiney key
and key slot is 0.00~0.051mm. Check the
protrusion after the whiney key is installed,
which shall be 1.392~1.739mm.

There are two pieces of crank shaft thrust
spacers, which are installed on the front and
rear thrust surfaces. Before installation, apply
some motor oil on the side of the thrust spacer
with oil groove and make this side towards the
cylinder block and the other side towards the
crank shaft.

Apply some motor oil on the main journal,
connecting rod journal, thrust surface and
bearing shell before the crank shaft is
installed.

The top of the main bearing cap is cast with
numbers- 1, 2, 3, 4, 5 and one arrow. During
the assembly, start the installation in a
front-to-back order and enable the guide
finger towards the front end surface of the
cylinder block. The width of 1, 2, 4, 5 main
bearing cap is same, but that of the third main
bearing cap is larger than others. The location
of the main bearing cap depends on the rabbet
and the rabbet and the cylinder block is
interference fit, with the interference to be
0.025~0.145mm. After the assembly, the sides
of the first and fifth main bearing cap shall be
even with or lower than the back and front
end surface of the cylinder block.

Among the main bearing bolts, 9 are
hexagonal-head flanged bolts and 1 is stud.
For transverse engine, the stud shall be
installed on the left threaded hole of the
second main bearing cap (seeing from the
front) for installing the support of the suction
strainer. For a north-south engine, the stud

shall be installed on the left threaded hole of
the fourth main bearing cap (seeing from the
front).

Apply some motor oil on the head joint before
installing the main bearing cap bolts.

Tighten the main bearing cap bolts and stud
by hands, then tighten them to the moment
of 90~100Nm.

The twist moment of the crank shaft
(assembly with piston connecting rod) is
16Nm max.

Oil baffle assembly

Removal

Take the oil baffle assembly out from the
right side of the back of the cylinder block
(seeing from the front)

Installation

Install the oil baffle assembly from the right
side of the back of the cylinder block (see
from the front). The tension spring of the oil
baffle assembly shall be lower than the
crankcase flange of the cylinder block.

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.

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

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.