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Great Wall engine 4G64S4M. Manual - part 13

11-46

(10)

Check whether the piston can rotate freely.

Mount of oil ring

(1)

Put the main ring of oil ring in the oil ring groove.

Remark:

1. The scraper blade and the main ring has the specified upper./lower

face.

2. The new main ring and scraper are colorful to identify its dimension.

(2)

Put in the upper scraper blade. When mounting the scraper blade,

press one end of the scraper blade in the piston oil ring groove, then

press the remaining part of scraper blade in the oil ring groove

shown as the figure by thumb.

Different from other piston ring, the use of ring pliers to expand the

scraper blade will break the scraper blade.

Notice:

Do not use the ring pliers to expand the scraper blade.

(3)

Mount the lower scraper blade in the same procedure of Step (2).

(4)

The scraper blade should be confirmed whether can rotate freely

to left and right after the mount.

Mount of First and Second Air Ring

(1)

The first air ring should be mounted after the second air ring is

mounted with the ring pliers.

Remark:

1. There is identification mark at the ring end.

Identification mark:

First ring

Second ring

2. Mount the piston ring and be sure the identification mark should face

upwardly to the top of the piston.

3. The dimension marks of piston ring are as follows:

6EN0 298

upper scraper blade

main ring

lower scraper blade

6EN1019

Dimension

Identification Color

Standard value

None

0.50mm larger

Red

1.00mm larger

Yellow

clearance of scraper blade

1EN0269

Dimension

Dimension mark

Standard value

None

0.50mm larger

1.00mm larger

100

ring pliers

7EN0452

identification mark

direction mark

first ring

second ring

9EN0524

ENGINE

CYLINDER HEAD AND VALVE

11-47

upper scraper blade

crankshaft

pulley side

openings of second and
main rings

lower balde

6ENO549

Mount of Piston and Connecting Rod Cluster

(1)

Coat enough engine oil on the piston, air ring and oil ring.

(2)

Adjust the openings of the air ring and oil ring (scraper blade

and the main ring) to the place shown in the figure.

(3)

Rotate the crankshaft until the crank pin locates the position of

the cylinder hole.

(4)

Threaded protective device should be adopted on the connect-

ing rod bolt before the insertion of the piston and connection

rod cluster in the cylinder. Carefulness is needed not to

damage the crank pin.

(5)

Insert the piston and connecting rod cluster in the cylinder

with the suitable press fitting SST for piston ring.

Notice:

There is a mark for forward face on the top of piston, which should

direct to the front of the engine (timing toothed belt side).

Mount of Connecting rod bearing

Where the bearing is needed to change, it should be selected and

mounted as per the following procedure.

(1)

Measure the outside diameter of the crank pin and determine

which group it belongs as per the following form, the crank-

shaft to be maintained should be marked at the position shown

in the figure with color paint to identify its dimension.

(2)

The identification mark of the connecting rod is printed at the

position shown in the figure.

Inside diameter of connecting rod; 48.000

48.015mm

(3)

Select the bearing from the group determined as per the Step

(1) and (2).

Bearing Selection, for example:

In case the outside diameter of the crank pin is measured as 44.

996mm, it belongs to the Group 1 in the above form. If the

repairing element for crankshaft needs to be changed, inspect

the identification color coated on the new crank pin. If the

color is yellow, the crank pin should belong to the first group,

therefore, the connecting rod bearing marked with

should be selected.

timing toothed belt

mark for forward face

1EN0247

NO.1

NO.2

NO.3

NO.4

6EN0700

6AE0115

identification mark

Crank pin

Connecting rod bearing

Yellow

44.995

45.000

Yellow

1.487

1.491

None

44.985

44.995

None

1.491

1.495

White

44.980

44.985

Blue

1.495

1.499

Identification

color

Outside

diameter

(mm)

Identification

mark

Identification

color

Thickness

(mm)

Group

ENGINE

CYLINDER HEAD AND VALVE

11-48

Mount of Connecting Rod Cap

(1)

When mounting the connecting rod cap, align the marks made

in disassembly well, if mounting the new member without

mark, the anti-rotary gap shown in the figure should be

mounted at the same side

(2)

Be sure the axial clearance at the larger end of connecting rod

is suitable.

Standard value: 0.10

0.25mm

Limit value: 0.4mm

Mount of Connecting Rod Nut

Notice:

In case the cylinder head is mounted before the mount of

connecting rod cap, dismantle the spark plug and then

mount on the connecting rod cap nut.

(1)

The connecting rod bolts and nuts should be tightened with the

method of tightening bolt at plastic zone. Before reusing the

bolt, check whether the bolt is expanded. Inspection method:

tighten the nut to the threaded part of the bolt by hand until it

passes the full thread. In case the nut cannot be screwed down

to the bottom, it can be judged the threaded part of the bolt may

be protracted, change the bolt on such condition.

(2)

Coat the oil on the threaded part and the seat face of the nut

before tightening the nut.

(3)

Tighten the nut on the bolt by hand and then screw the nuts down

in turns so as to assemble the connecting rod cap correctly.

(4)

Tighten the nut with the torque of 20N.M.

(5)

Coat the paint mark on each nut head.

(6)

Make paint mark on the bolt at the position 90

100

forward from the paint mark at nut head.

(7)

Tighten the nut by a angle of 90

100, until the marks on

the nut and the bolt are in alignment.

Notice:

If the screwing angle is less than 90, the tightening

property specified is cannot be guaranteed. Therefore,

attention should be paid to the screwing angle when

tightening.

In case the nut is over tightened, (the screwing angle is

more than 100

), loosen it thoroughly, and then re-

tighten it from the Step (1).

cylinder No.

anti-rotary gap

DEN0051

6EN0621

paint

marks

paint marks

100

6AE0298

ENGINE

CYLINDER HEAD AND VALVE

11-49

Inspection

Piston Ring

(1)

Check whether the piston ring has damage, over abrasion

or breakage, if it has, change it, in the case of changing the

piston, the piston ring needs to be changed too.

(2)

Check the clearance between the piston ring and the piston

ring groove, if it is over large, change the piston ring or the

both parts.

Standard value: 0.02

0.06mm

Limit value: 0.1mm

(3)

Put the piston ring in the cylinder and locate it with the

crown face of the piston, then measure the opening clear-

ance with the feeler. If the opening clearance is over large,

change the piston ring.

Standard value:

First ring

0.250.35mm

Second ring

0.400.55mm

Oil ring

0.100.40mm

Limit value:

First and second ring

0.8mm

Oil ring

1.0mm

Play of Crank Pin (clearance gauge of plastic cord)

(1)

Clear away the oil on the journal and bearing of the

connecting rod thoroughly.

(2)

Cut the clearance gauge of plastic cord in the length that is

the same with the bearing width, and then put them on the

crank handle and parallel them with the axial center line.

(3)

Mount on the connecting rod cap carefully and tighten the

nut as per the specified torque.

(4)

Dismantle the connecting rod cap carefully.

(5)

Measure the max width of the flattened plastic cord with

the gauging ruler printed on the package bag of the clear-

ance gauge of plastic cord, thus obtaining the clearance

value.

Standard value: 0.02

0.05mm

Limit value: 0.1mm

5EN0066

press it in with piston

priston ring

opening clearance

5EN0548

1EN0246

clearance gauge of plastic cord

1EN0271

ENGINE

CYLINDER HEAD AND VALVE

Content .. 11 12 13 14 ..