Mitsubishi Lancer Evolution VI. Manual - part 21

ENGINE  – 

Piston and Connecting Rod

11-59

PISTON AND CONNECTING ROD

REMOVAL AND INSTALLATION

Apply engine oil to all
moving parts before
installation.

1

2

3

4

5

6

7
8

9

10

11

12

20 Nm + 90

_

 to 94

_

Removal steps

"

G

A

1. Connecting rod nut

A

A

" "

F

A

2. Connecting rod cap

"

E

A

3. Connecting rod bearing

"

D

A

4. Piston and connecting rod assem-

bly

5. Connecting rod bearing

"

C

A

6. Piston ring No. 1

"

C

A

7. Piston ring No. 2

"

B

A

8. Oil ring

A

B

" "

A

A

9. Piston pin

10. Piston

11. Connecting rod

12. Bolt

ENGINE  – 

Piston and Connecting Rod

11-60

REMOVAL SERVICE POINTS

A

A

"

CONNECTING ROD CAP REMOVAL

(1) Mark the cylinder number on the side of the connecting

rod big end for correct reassembly.

(2) Keep the removed connecting rods, caps, and bearings

in order according to the cylinder number.

A

B

"

PISTON PIN REMOVAL

(1) Insert the special tool, Push Rod, into the piston from

the side on which the front mark is stamped in the piston
head, and attach the guide C to the push rod end.

(2) Place the piston and connecting rod assembly on the

special tool, Piston Pin Setting Base, with the front mark
facing upward.

(3) Using a press, remove the piston pin.

NOTE
Keep the disassembled pistons, piston pins and
connecting rods in order according to the cylinder number.

ENGINE  – 

Piston and Connecting Rod

11-61

INSTALLATION SERVICE POINTS

"

A

A

PISTON PIN INSTALLATION

(1) Measure the following dimensions of the piston, piston

pin and connecting rod.
A: Piston pin insertion hole length
B: Distance between piston bosses
C: Piston pin length
D: Connecting rod small end width

(2) Obtain dimension L (to be used later) from the above

measurements by using by following formula.

L = 

(A – C) – (B – D)

2

(3) Insert the special tool, Push Rod, into the piston pin and

attach the guide A to the push rod end.

(4) Assemble the connecting rod in the piston with their front

marks facing the same direction.

(5) Apply engine oil to the entire periphery of the piston pin.
(6) Insert the piston pin, push rod and guide A assembly

having assembled in step (3) from the guide A side into
the piston pin hole on the front marked side.

(7) Screw the guide B into the guide A until the gap between

both guides amounts to the value L obtained in step
(2) plus 3 mm.

(8) Place the piston and connecting rod assembly onto the

piston setting base with the front marks directed upward.

(9) Press-fit the piston pin using a press.

If the press-fitting force required is less than the standard
value, replace the piston and piston pin set or/and the
connecting rod.

Standard value: 7,350 – 17,200 N

      3 mm + L

ENGINE  – 

Piston and Connecting Rod

11-62

(10)Check that the piston moves smoothly

"

B

A

OIL RING INSTALLATION

(1) Fit the oil ring spacer into the piston ring groove.

NOTE
1.

The side rails and spacer may be installed in either
direction.

2.

New spacers and side rails are colored for
identification of their sizes.

Size

Identification color

Standard

None

0.50 mm oversize

Red

1.00 mm oversize

Yellow

(2) Install the upper side rail.

To install the side rail, first fit one end of the rail into
the piston groove, then press the remaining portion into
position by finger. See illustration.
Use of ring expander to expand the side rail end gap
can break the side rail, unlike other piston rings.

Caution
Do not use piston ring expander when installing side
rail.

(3) Install the lower side rail in the same procedure as

described in step (2).

(4) Make sure that the side rails move smoothly in either

direction.

6EN1237

Lower side rail

Spacer

Upper 
side rail

1EN0269

Side rail gap