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Mitsubishi Lancer Evolution VI. Manual - part 22

ENGINE –

Piston and Connecting Rod

11-63

PISTON RING NO. 2 / PISTON RING NO. 1
INSTALLATION

(1) Using piston ring expander, fit No. 2 and then No. 1 piston

ring into position.

NOTE
1.

The ring end is provided with identification mark.

Item

Identification mark

No. 1 ring

No. 2 ring

Install piston rings with identification mark facing up,
to the piston crown side.

Size marks on position rings are as follows.

Size

Size mark

Standard

None

0.50 mm oversize

1.00 mm oversize

100

PISTON AND CONNECTING ROD ASSEMBLY
INSTALLATION

(1) Liberally coat engine oil on the circumference of the piston,

piston ring, and oil ring.

(2) Arrange the piston ring and oil ring gaps (side rail and

spacer) as shown in the figure.

(3) Rotate the crankshaft so that crank pin is on the center

of cylinder bore.

(4) Use suitable thread protectors on the connecting rod bolts

before inserting piston and connecting rod assembly into
the cylinder block.
Care must be taken not to nick the crank pin.

(5) Using a suitable piston ring compressor tool, install the

piston and connecting rod assembly into the cylinder block.

CONNECTING ROD BEARINGS INSTALLATION

When the bearing needs replacing, select and install a proper
bearing by the following procedure.
(1) Measure the crankshaft pin diameter and confirm its

classification from the following table. In the case of a
crankshaft supplied as a service part, identification colors
of its pins are painted at the positions shown in the
illustration.

9EN0524

Identification mark

Side mark

No. 1

No. 2

Timing belt side

ENGINE –

Piston and Connecting Rod

11-64

(2) The connecting rod bearing identification mark is stamped

at the position shown in the illustration.

Crankshaft pin

Connecting rod bearing

Classi-
fication

Identifica-
tion mark

Identifi-
cation
color

O. D. mm

Identi-
fication
mark

Thickness mm

Produc-
tion part

Service
part

None

Yellow

44.995 – 45.000

1.483 – 1.487

None

44.985 – 44.995

1.487 – 1.491

None

White

44.980 – 44.985

1.491 – 1.495

Connecting rod I.D.: 48.000 – 48.015 mm

(3) Select a proper bearing from the above table on the basic

of the identification data confirmed under items (1) and
(2).

[Example]
If the measured value of a crankshaft pin outer diameter
is 44.996 mm, the pin is classified as “1” in the table.
In case the crankshaft is also replaced by a spare part,
check the identification colors of the pins painted on the
new crankshaft. If the color is yellow, for example, the
pin is classified as “1”. In the above cases, select the
connection rod bearing having identification mark “0”.

CONNECTING ROD CAP INSTALLATION

(1) Verifying the mark made during disassembly, install the

bearing cap to the connecting rod. If the connecting rod
is new with no index mark, make sure that the bearing
locking notches come on the same side as shown.

(2) Make sure that the connecting rod big end side clearance

meets the specification.

Standard value: 0.10 – 0.25 mm

Limit: 0.4 mm

Identification mark

ENGINE –

Piston and Connecting Rod

11-65

CONNECTING ROD CAP NUT INSTALLATION

Caution
If the cylinder head has been installed before installing
the connecting rod cap nut, be sure to remove the spark
plugs.

(1) Since the connecting rod cap bolts and nuts are torqued

using the plastic area tightening method, the bolts should
be examined BEFORE reuse. If the bolt threads are
“necked down”, the bolt should be replaced.
Necking can be checked by running a nut with fingers
to the full length of the bolt threads. If the nut does not
run down smoothly, the bolt should be replaced.

(2) Before installation of each nut, apply engine oil to the

thread portion and bearing surface of the nut.

(3) Install each nut to the bolt and tighten it with fingers.

Then tighten the nuts alternately to install the cap properly.

(4) Tighten the nuts to a torque of 20 Nm.
(5) Make a paint mark on the head of each nut.
(6) Make a paint mark on the bolt end at the position 90

to 94

from the paint mark made on the nut in the direction

of tightening the nut.

(7) Give a 90

to 94

turn to the nut and make sure that

the paint mark on the nut and that on the bolt are in
alignment.

Caution
1.

If the nut is turned less than 90

, proper fastening

performance may not be expected. When
tightening the nut, therefore, be careful to give
a sufficient turn to it.

If the nut is overtightened (exceeding 94

), loosen

the nut completely and then retighten it by
repeating the tightening procedure from step (1).

INSPECTION

PISTON RING

(1) Check the piston ring for damage, excessive wear, and

breakage and replace if defects are evident. If the piston
has been replaced with a new one, the piston rings must
also be replaced with new ones.

(2) Check for the clearance between the piston ring and

ring groove. If the limit is exceeded, replace the ring or
piston, or both.

Standard value:

No. 1 ring

0.04 – 0.075 mm

No. 2 ring

0.02 – 0.06 mm

Limit: 0.1 mm

6AE0298

to 94

Paint mark

Paint
mark

Nut

Bolt

ENGINE –

Piston and Connecting Rod

11-66

(3) Install the piston ring into the cylinder bore. Force it down

with a piston, its crown being in contact with the ring,
to correctly position it at right angles to the cylinder wall.
Then, measure the end gap with a feeler gauge. If the
ring gap is excessive, replace the piston ring.

Standard value:

No. 1 ring

0.25 – 0.35 mm

No. 2 ring

0.40 – 0.55 mm

Oil ring

0.10 – 0.40 mm

Limit:

No. 1, No. 2 ring 0.8 mm
Oil ring 1.0 mm

CRANKSHAFT PIN OIL CLEARANCE
(PLASTIC GAUGE METHOD)

(1) Remove oil from the crankshaft pin and connecting rod

bearing.

(2) Cut the Plastigage to the same length as the width of

the bearing and place it on the crankshaft pin in parallel
with its axis.

(3) Install the connecting rod cap carefully and tighten the

nuts to specified torque.

(4) Carefully remove the connecting rod cap.
(5) Measure the width of the Plastigage at its widest part

by using a scale printed on the Plastigage package.

Standard value: 0.03 – 0.05 mm

Limit: 0.1 mm

Plastigage

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