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Chery A18. Manual - part 37

Diameter of 480M piston skirt

(unit: mm)

Diameter of 480E

piston skirt (unit: mm)

Diameter of UAES’s

new two-valve piston

skirt (unit: mm)

79.91-79.92

79.915-79.925

79.92-79.93

79.925-79.935

79.93-79.94

79.935-79.94

Ex-factory

grouping

79.94-79.95

79.945-79.955

80.20-80.21

80.205-80.215

80.21-80.22

80.215-80.225

Ex-factory

repair

80.22-80.23

80.225-80.235

Standard

79.93-79.955

79.965-79.975

Oversized by 0.29

80.21-80.235

80.245-80.255

Spare

parts

Oversized by 0.5

80.43-80.455

80.465-80.475

80.435-80.455

Measure the diameter of piston pin bore

Diameter of 480M piston pin bore (unit: mm)

Diameter of 480E piston pin bore (unit: mm)

White

20.630-20.633

White

20.630-20.633

Red

20.633-20.636

Red

20.633-20.636

Blue

20.636-20.639

Blue

20.636-20.639

Measure the diameter of the piston pin

Diameter of 480M piston pin bore (unit: mm)

Diameter of 480E piston pin bore (unit: mm)

White

20.622-20.625

White

20.622-20.625

Red

20.625-20.628

Red

20.625-20.628

Blue

20.628-20.631

Blue

20.628-20.631

Measure the end clearance of the piston
ring
First compression ring: 0.30-0.50mm

Second compression ring: 0.30-0.50mm

Oil ring: 0.40-1.40mm

Measure the axial clearance of piston ring in the piston groove

Height of the piston

ring (unit: mm)

Size of piston ring
groove (unit: mm)

Fit clearance

(unit: mm)

First compression ring

1.60

1.6

0.050-0.082

Second compression

ring

2.0

0.050-0.082

0.61±0.025

Sealing strip of oil ring

Spring of oil ring

2.68±0.05

4.0

0.01-0.23

Cast iron oil ring

4.0

0.025-0.055

480 UAES’s new two-valve

Height of the piston ring

(unit: mm)

Size of piston ring groove

(unit: mm)

First compression

ring

1.2（-0.03～-0.01）

1.2（0.03～0.05）

Second

compression ring

1.5（-0.03～-0.01）

1.5（0.02～0.04）

0.46±0.02

Sealing strip of

oil ring

Spring of oil ring

2.75±0.05

2.0±0.02

3（0.01～0.03）

Measure the small-end bore diameter of the
connecting rodΦ20.589

Check whether the big-end injection hole of the
connecting rod is blocked, with the outlet
diameter to be Φ1mm.

0
-0.012

-0.015
-0.025

+0.03
+0.01

+0.03

+0.01

+0.06

+0.04

+0.06

+0.04

Installation

Piston  weights  and  spare  piston  skirts  are  not
grouped,  but  the  piston  pin  holes  shall  be
grouped.  Before  assembly,  check  the  piston
crown  marks.  The  marks  of  the  four  cylinders
must be same.

Heat  the  small  end  of  the  connecting  rod  to
230~400℃, apply SAE50  lube or glue type of
graphite  oil,  then  press  the  piston  pin  into the
small  end  bore  of  the  connecting  rod  and  the
piston pin  bore. One end of the piston pin can
be  0.7mm（max）higher  than  the  pin  boss  or
lower than the pin seat, and the other end shall
be in the pin boss.

The  forward  pointing  arrow  on  the  piston
crown  and  the  forward  pointing  bump  on  the
external  surface  of  the  piston  pin  seat shall  be
in the same direction with the “F” near the big
end  on  the  connecting  rod  body  (For  some
blanks forged with the number “480”, the side
with the number shall be upward.

After connecting the piston, piston pin and the
connecting rod together, print or chisel the
cylinder number (size: 3mm) on the top of the
piston, connecting rod body and left of the
connecting rod cap. The printing shall not lead
to the distortion of the junction plane.

When  installing  the  piston  ring,  the  side  with
characters  shall  be  upward  and  the  external
slit  of  the  second  compression  ring  shall  be
downward.  Detailed  order  is  as  follows:  (1)
install  the  oil  control  piston  ring;  (2)  install
the  second  compression  ring  and  (3)  install
the first compression ring. When installing the
ring,  the  max.  expanding  must  be  less  than
(size  of  cylinder  bore  +  1.65mm)  ,  otherwise
the  ring  is  subject  to  distortion  or  broken off.
The opening of the two sealing strips of Steel
belt  combination  oil  control  ring  shall  be
staggered  from  each  other  by  120°while  the
one of cast iron  oil  ring  shall  be stagger from
that  of  spiral  bushing  ring  by  180°.  The
piston shall  be able to rotate freely in the ring
groove and no jamming shall exist.

Forward
pointing bump

First compression ring

compression ring

Steel belt combination
oil control ring

Cast spiral oil control ring

Only one side

Size of piston ring

INSTALLATION OF THE PISTON AND
CONNECTING ROD ASSEMBLY

Apply some motor oil in the piston, piston ring
and  cylinder,  with  the  first  and  second
compression  ring  staggered  from  the  opening
of  the  oil  control  piston  ring  by  120°,  then
install  the  piston  and  connecting  rod  assembly
into  the  cylinder.  The  piston  and  connecting
rod  assembly  may  be  pushed  into  the  cylinder
by a hammer.

Apply  some    motor  oil  on  the  connecting-rod
bearing shell and install the connecting rod cap
and  body.  The  connecting  rod  cap  is  fixed  by
two elastic dowels.

Tighten the connecting rod bolts to the moment
of 30-36N.m. Before installation, apply some
motor oil on the bolt heads and threads.

The side clearance of the big end of the
connecting rod is 0.0092-0.268mm.

480# piston ring

Paint mark (type)

No paint (Standard)

Purple paint (oversized by 0.29)

Blue paint (oversized by 0.5)

Content .. 35 36 37 38 ..