Mitsubishi Colt Ralliart. Manual - part 268

AK305409AB

Length

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <4A9>

11B-36

3. Measure the valve overall length. If the measured 

value exceeds the limit, replace with a new valve.

Standard value:

Intake 89.61 mm
Exhaust 90.94 mm

Limit:

Intake 89.11 mm
Exhaust 90.44 mm

VALVE SPRING

AK305410AB

Free height

Squareness

1. Measure the valve spring free height. If the 

measured value exceeds the limit, replace with a 
new spring.

Standard value: 43.1 mm
Limit: 42.1 mm

2. Measure the valve spring out-of-squareness. If 

the measured value exceeds the limit, replace 
with a new spring.

Standard value: 2

° or less

Limit: 4

°

VALVE GUIDE

AK300168

Guide inside diameter

Stem diameter

Valve 
guide

AE

Measure the clearance between the valve guide and 
the valve stem. If the measured value exceeds the 
limit, replace the valve guide or the valve, or both.

Standard value:

Intake 0.020 

− 0.047 mm

Exhaust 0.030 

− 0.057 mm

Limit:

Intake 0.10 mm
Exhaust 0.15 mm

VALVE SEAT

AK305615AB

Valve stem
projection

Valve stem end

Spring seat surface

With the valve mechanism assembled and the valve 
face pressed against the seat, measure the valve 
stem end protrusion over the cylinder head face 
where the spring seat is located. If the measured 
value exceeds the limit, replace the cylinder head 
assembly.

Standard value:

Intake 38.46 mm
Exhaust 38.49 mm

Limit:

Intake 38.96 mm
Exhaust 38.99 mm

Main

Index

Group

TOC

PISTON AND CONNECTING ROD

ENGINE OVERHAUL <4A9>

11B-37

PISTON AND CONNECTING ROD

REMOVAL AND INSTALLATION

M1113008401457

AK402343

AC

6

9

10

7

1

5

4

3

2

8

15 ± 2 N·m 

→ +90˚ to 94˚

11

Apply engine oil to
all moving parts
before installation.

Removal steps 

>>

G

<< 1. Connecting rod cap bolt

<<

A

>> >>

F

<< 2. Connecting rod cap

>>

E

<< 3. Connecting rod bearing

>>

D

<< 4. Piston, connecting rod assembly

>>

E

<< 5. Connecting rod bearing

>>

C

<< 6. Piston ring, No. 1

>>

C

<< 7. Piston ring, No. 2

>>

B

<< 8. Oil ring

<<

B

>> >>

A

<< 9. Piston pin

10.Piston
11.Connecting rod

Removal steps (Continued)

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Index

Group

TOC

PISTON AND CONNECTING ROD

ENGINE OVERHAUL <4A9>

11B-38

REMOVAL SERVICE POINTS
<<A>> CONNECTING ROD CAP 
REMOVAL

AK304890AC

Cylinder No.

Front mark

To facilitate reassembly, mark the side face of the 
connecting rod big end with the corresponding cylin-
der number.

<<B>> PISTON PIN REMOVAL

AK305415AB

Push rod

Base

Guide B

Guide C

Guide D

(MB991659)

Guide A: 17.9 mm

Guide A: 18.9 mm

Guide A: 20.9 mm

Guide A: 21.9 mm

The special tool Piston pin setting tool (MD998780) 
consists of the parts illustrated. The special tool 
Guide D (MB991659) is also used for removal.

AK305425AB

Guide D

Base

Push rod

Piston pin

Front mark

1. Insert the Push rod (special tool) into the piston, 

from the piston side with the front mark on the 
piston top face. Install the Guide D on the other 
side.

2. Install the piston and connecting rod assembly 

with the tools onto the Piston pin setting base 
(special tool), ensuing that the piston front mark 
faces upwards.

3. Using a press, remove the piston pin.

NOTE: With the piston pin removed, keep the pin, 
piston and connecting rod of the same cylinder 
together.

INSTALLATION SERVICE POINTS
>>A<< PISTON PIN INSTALLATION

1. Insert the special tool Push rod into the piston pin, 

and install Guide A.

AK306099

AB

Front mark

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Index

Group

TOC

PISTON AND CONNECTING ROD

ENGINE OVERHAUL <4A9>

11B-39

2. Assemble the piston and the connecting rod 

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

3. Apply engine oil onto the periphery of the piston 

pin.

4. 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.

AK305774

L

Guide A

Guide B

AC

5. Insert Guide B into Guide A with having 2.25 mm 

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

AK305424AB

Guide A

Base

Guide B

Push rod

Piston pin

Front mark

6. Install the piston and connecting rod assembly 

with the tools onto the Piston setting base (special 
tool), ensuring that the piston front mark faces 
upwards.

7. 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: 5,000 

− 11,000 N 

>>B<< OIL RING INSTALLATION

1. Install the oil ring spacer first into the piston ring 

groove, 
followed by the upper side rail and then the lower 
side rail.
NOTE: New spacers and side rails are an identi-
fied by color marks as follows:

Size

Color mark

Standard

Non mark

0.25 mm oversize

Two blue

CAUTION

Do not use a ring expander on side rails as they 
may break when the gap is opened.

AK304891

2. Side rails can be installed easily by first inserting 

one end of the rail into the piston groove, then 
pressing the rail into place with finger.

3. With the side rails installed onto the piston, check 

that they can be rotated smoothly in both 
directions.

AK103812AC

Upper
side
rail
closed
gap

Lower
side
rail
closed
gap

Spacer closed gap

4. The gaps of the side rails and spacer should be 

located as illustrated.

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TOC