Mitsubishi Colt Ralliart. Manual - part 269

PISTON AND CONNECTING ROD

ENGINE OVERHAUL <4A9>

11B-40

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

AK304892AB

Piston ring
expander

Use a piston ring expander to install the No. 1 and
No. 2 piston rings. The ring identification mark should
face upwards.

AK402172

No. 2

No. 1

Size marks

Identification mark

Identification mark

No. 1 ring: None
No. 2 ring: 2R

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

Size

Size mark

Standard No. 1 ring No mark

(Yellow paint on periphery)

No. 2 ring No mark

(Yellow paint on periphery)

0.25 mm oversize

>>D<< PISTON, CONNECTING ROD
ASSEMBLY INSTALLATION

1. Apply engine oil sufficiently onto the piston

periphery, the piston rings and the oil ring.

AK202730

No. 1

No. 2

Side rail

Piston pin

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

(side rails, spacer) as illustrated.

3. Insert the piston and connecting rod assembly

from above the cylinder block and through the
cylinder bore, ensuring that the front mark on the
piston top faces the camshaft sprocket.

AK304957

CAUTION

Do not try to strike hard on the assembly to fit it
in place as this will break the piston rings.
4. While firmly holding the piston rings with a ring

band, insert the piston and connecting rod
assembly into place.

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Index

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TOC

PISTON AND CONNECTING ROD

ENGINE OVERHAUL <4A9>

11B-41

>>E<< CONNECTING ROD BEARING
INSTALLATION

AK305607AB

Identification
color

1. Connecting rod bearings are color coded with

paint at the illustrated locations. Bearings should
be selected based on the following table.

Connecting rod bearing
Upper bearing

Lower bearing

Blue

Red

Blue

Yellow or black

Example: If a blue upper bearing is selected, the
lower bearing must be red.

2. Install the bearings selected onto the connecting

rod big end and the bearing cap.

AK306100

3. Measure the illustrated location. The error should

be within 0.5 mm.

>>F<< CONNECTING ROD CAP
INSTALLATION

AK304890AC

Cylinder No.

Front mark

1. Install the correct bearing cap onto the

corresponding connecting rod, based on the
marking placed during disassembly.

AK304900

2. Ensure that the thrust clearance of the connecting

rod big end is to specification.

Standard value: 0.10

− 0.35 mm

Limit: 0.4 mm

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PISTON AND CONNECTING ROD

ENGINE OVERHAUL <4A9>

11B-42

>>G<< CONNECTING ROD CAP BOLT
INSTALLATION

1. Inspect all reused connecting rod bolts according

to the following procedure.

AK401052

15 mm

30 mm

(1) Measure the outside diameter at 15 mm and

30 mm from the head of the connecting rod
bolts shown in Figure respectively.

(2) When the difference between the outside

diameters (measured at 15 mm and 30 mm)
exceeds the standard value, replace the
connecting rod bolts.

Standard value: 0

− 0.1 mm

2. Apply engine oil to the threaded portion and

seating face of the bolt.

3. To correctly install the cap, loosely install the bolts

with fingers.

4. Alternately, tighten the bolts in several steps to the

specified torque of 15

± 2 N⋅m.

AK304894AC

90˚ to 94˚

Paint
mark

5. Put a paint mark on the bolt head as illustrated.
6. Put another paint mark on the bolt head at 90 to

94 degree angle in the tightening direction from
the first paint mark.

CAUTION

• If the bolt is tightened less than the specified

lower limit of 90 degree angle, the bolt may
become loose. Be sure to tighten correctly.

• If the bolt is tightened in excess of the speci-

fied upper limit of 94 degree angle, loosen the
bolt completely and repeat the entire proce-
dures.

7. Tighten the bolt 90 to 94 degree angle. The paint

mark on the connecting rod should be aligned
with the paint mark on the bolt.

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Index

Group

TOC

PISTON AND CONNECTING ROD

ENGINE OVERHAUL <4A9>

11B-43

INSPECTION

M1113008500837

PISTON RING

AK304899

1. Measure the clearance between the piston ring

and the ring groove. If the measured value
exceeds the limit, replace the piston ring, or both
the piston and the piston ring.

Standard value:

No. 1 ring: 0.03

− 0.07 mm

No. 2 ring: 0.02

− 0.06 mm

Limit: 0.1 mm

AK305608AB

End gap

Piston ring

Press down ring
with piston

2. Insert the piston ring into the cylinder bore. Insert

the piston with the top face end first into the
cylinder bore, pushing the piston ring and
positioning it squarely with the cylinder bore.
Then, measure the piston ring end gap using a
feeler gauge. If the measured value exceeds the
limit, replace the piston ring.

Standard value:

No. 1 ring: 0.15

− 0.30 mm

No. 2 ring: 0.20

− 0.40 mm

Oil ring: 0.10

− 0.40 mm

Limit:

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

CRANKSHAFT PIN OIL CLEARANCE
(PLASTIGAGE METHOD)

1. Wipe off oil from the crankshaft pin and the

connecting rod bearings.

2. Place a plastigage, with a length equal to the

bearing width, onto the crank pin in the axial
direction.

AK304897AB

Plastigage

3. Carefully install the connecting rod cap over the

plastigage, and tighten the bolts to 15

± 2 N⋅m →

+ 90 to 94 degree angle.

4. Remove the bolts. Slowly remove the connecting

rod cap.

AK304898AB

Plastigage

5. Using the measure printed on the plastigage

package, measure the width (widest portion) of
the crushed plastigage.

Standard value: 0.014

− 0.059 mm

Limit: 0.1 mm

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