Mitsubishi Lancer Evolution IX. Manual — part 92

PISTON AND CONNECTING ROD

ENGINE OVERHAUL

11B-59

NOTE: Keep the disassembled pistons, piston
pins and connecting rods cylinder by cylinder.

INSTALLATION SERVICE POINTS
>>A<< PISTON PIN INSTALLATION

1. When replacing a piston, check the cylinder bore

size mark stamped at the indicated location on the
cylinder block and select an appropriate
replacement piston using the following table.

NOTE: The piston size mark is located on the pis-
ton top surface.

2. Insert the special tool Push Rod into the piston

pin, and install Guide A.

3. Assemble the piston and the connecting rod

together, ensuring that their front marks are
aligned with each other.

4. Apply engine oil onto the periphery of the piston

pin.

5. Insert the piston pin assembled in Step 1 above

into the piston pin boss. Guide A end of the piston
pin should be inserted first into the front mark end
of the boss.

6. Insert Guide B into Guide A with having 1.25 mm

of the clearance "L" between Guide A and B.

7. Install the piston and connecting rod assembly

with the tools onto the special tool Piston Setting
Base, ensuring that the piston front mark faces
upwards.

8. Using a press, press fit the piston pin. If the force

required to press fit the piston pin is less than the
standard value, replace the piston pin (piston
assembly) or the connecting rod, or both.

Standard value: 7,350

− 17,100 N

>>B<< OIL RING INSTALLATION

1. Fit the oil ring coil expander and oil ring into the

piston ring groove.
NOTE: Locate the oil ring and coil expander end
gaps as shown in the drawing.
NOTE: New coil expander and oil ring are an
identified by colour marks as follows:

Cylinder bore size mark

Piston size mark

I

A

II

No mark

III

C

AK202923

Crankshaft
bore size mark

Timing belt side

No.4

No.1

No.2

No.3

AB

AK304522

L

Guide A

Guide B

AC

AK501783

P

P

Push rod

Front mark

Front mark

AB

Base

Guide A

Guide B

AK502373

Coil expander
end gap

Oil ring
end gap

AB

PISTON AND CONNECTING ROD

ENGINE OVERHAUL

11B-60

CAUTION

Use of ring expander to expand the oil ring end
gap can break the oil ring, unlike other piston
rings.

2. To install each coil expander, first fit one end of

the oil ring into the piston groove, then press the
remaining portion progressively into position by
finger as shown in the drawing.

3. Make sure that the installed oil ring move

smoothly in either direction.

>>C<< PISTON RING NO. 2 / PISTON
RING NO. 1 INSTALLATION

Using a piston ring expander, install the piston rings
with their identification marks facing up (toward the
piston crown).

Identification marks:

No.1 ring: 1R
No.2 ring: 2R

NOTE: Each of the available piston rings has a size
mark as follows:

>>D<< PISTON AND CONNECTING ROD
ASSEMBLY INSTALLATION

1. Apply engine oil generously to the piston's outside

surface, piston rings, and oil ring.

2. Align the end gaps of the piston rings and oil ring

(oil ring and coil expander) as shown in the
drawing.

3. Insert the piston and connecting rod assembly

from the top of cylinder with the front mark on the
crown toward the camshaft sprocket.

4. Not to damage the crank pin, attach a special tool

Bolt guide (MB992010), to the connecting rod
bolt.

Size

Colour mark

Standard

No mark

0.50 mm oversize

Red

1.00 mm oversize

Yellow

AK202785

Oil ring end

AD

AK202786

Piston ring
expander

AC

AK202807

No. 2

AB

No. 1

Size marks

Identification mark

Size

Size mark

Standard No. 1 ring No mark (white paint on

periphery)

No. 2 ring No mark

0.50 mm oversize

50

1.00 mm oversize

100

AK202730

No. 1

No. 2

AE

Piston pin

Coil expander

Oil ring

AK402300AC

MB992010

Bolt

Connecting rod

PISTON AND CONNECTING ROD

ENGINE OVERHAUL

11B-61

CAUTION

• Do not strike the assembly with a large force.

Doing so could break the piston rings.

• When striking the assembly into cylinder, do

not allow it to interfere with the oil jet.

5. Use a piston ring band to hold the piston rings

compressed when inserting the piston and
connecting rod assembly into the cylinder.

>>E<< CONNECTING ROD BEARING
INSTALLATION

1. When replacing the connecting rod bearing,

select a bearing of the size appropriate for the
crankshaft pin diameter in accordance with the
crankshaft pin and connecting rod bearing
matching table shown below.

2. Crankshaft pin diameter marks are stamped in the

indicated locations.

3. Connecting rod bearing identification mark is

stamped in the indicated location on each
bearing.

<Bearing selection example>
If the crankshaft pin diameter mark is “I,” select a
bearing marked “1.”
If the crankshaft pin diameter mark is illegible,
measure the pin diameter and select a bearing
with the mark corresponding to the measurement.

4. Install the upper and lower halves of the selected

bearing on the connecting rod big end and cap,
respectively.

>>F<< CONNECTING ROD CAP
INSTALLATION

1. Install the bearing cap on the connecting rod while

aligning the marks made during disassembly. If
the connecting rod is new and has no alignment
mark, assemble it with the cap such that the both
bearing locating notches are on the same side as
shown in the drawing.

AK202798

AK202909

Locations of crankshaft pin diameter
marks

No. 3

No. 1

No. 2

No. 4

AB

AK203964AC

Identification mark

Crankshaft pin

Connecting rod
bearing

Identification
mark

Diameter mm

Identification
mark

I

44.995

− 45.000 0

II

44.985

− 44.995 1

III

44.980

− 44.985 2

AK202813

Cylinder
number

Bearing
locating
notches

AB

AK202821

PISTON AND CONNECTING ROD

ENGINE OVERHAUL

11B-62

2. Make sure that the thrust clearance of the

connecting rod big end is proper.

Standard value: 0.10

− 0.25 mm

Limit: 0.4 mm

>>G<< CONNECTING ROD CAP NUT
INSTALLATION

1. The connecting rod cap bolts and nuts are

tightened using the torque-to-yield method. For
this reason, each bolt to be reused must be
checked for elongation before installation.
Whether or not the bolt has been elongated can
be determined by running a nut with fingers
through all the threads of the bolt. If the nut does
not turn smoothly over all the threads, the bolt has
been elongated and must be replaced.

2. Apply engine oil to the threads and bearing

surface of each nut before installation.

3. Finger-tighten the nuts on the bolts, then tighten

the nuts alternately and repeatedly to install the
cap properly.

4. Tighten the nuts to a torque of 20

± 2 N⋅m.

5. Make a paint mark on the head of each nut.

CAUTION

• If the tightening angle is less than 90°, ade-

quate tightness could not be assured.

• If the tightening angle exceeds 94°, loosen the

nut completely and then perform the tighten-
ing procedure again beginning with the first
step.

6. Make a paint mark on the bolt at a point 90

° to 94°

away from the paint mark made on the nut in the
tightening direction.

7. Turn the nut 90

° to 94° to bring the mark on the

nut into alignment with that on the bolt.

INSPECTION

M1113008500990

PISTON RING

1. Measure the clearance between each piston ring

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

Standard values:

No. 1 ring: 0.03

− 0.07 mm

No. 2 ring: 0.02

− 0.06 mm

Limits: 0.1 mm

2. Install a piston ring or oil ring side rail into the

cylinder bore and force it down with the head of a
piston until the ring is at right angles to the
cylinder wall. Measure the end gap with a
thickness gauge.
NOTE: If the end gap is excessive, replace the
piston ring.

Standard values:

No. 1 ring: 0.20

− 0.30 mm

No. 2 ring: 0.30

− 0.50 mm

Oil ring: 0.10

− 0.40 mm

Limits:

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

AK300612

Paint marks

Nut

Bolt

Paint marks

90˚ to 94˚

AC

AK202787

AK202788

Force ring down
with piston

End gap

Piston ring

AB