Mitsubishi Evolution X. Manual - part 205

AK600791

No. 2

No. 1

Identification mark

AC

PISTON AND CONNECTING ROD

TSB Revision

ENGINE OVERHAUL

11B-67

Identification mark

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

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

Size

Size mark

Standard

No mark

0.25 mm (0.010 inch) 
oversize

25

.

>>D<< PISTON CONNECTING ROD ASSEMBLY 
INSTALLATION

1. Apply a sufficient amount of engine oil to the circumference 

of the piston, piston rings and oil ring.

AK400403

No.1

Side rail

Side rail

AC

Piston pin

No.2

2. Arrange end gap positions of piston rings and oil ring (side 

rail and spacer) as shown in the illustration.

3. Insert the piston and connecting rod assembly from the top 

surface of the cylinder block with the front mark of the piston 
top face facing toward the timing chain side.

AK502730

CAUTION

Driving it in hard causes breakage of piston rings and 
damage to the crank pin.
4. Firmly tighten the piston ring with a ring band and insert the 

piston and connecting rod assembly.

.

PISTON AND CONNECTING ROD

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ENGINE OVERHAUL

11B-68

>>E<< CONNECTING ROD BEARING 
INSTALLATION

AK702193AD

No.1

No.2

No.3

No.4

Crankshaft pin identification stamp position

Crankshaft
front end

1. When replacing a connecting rod bearing, select the bearing 

corresponding to the crankshaft pin outside diameter 
according to the crankshaft pin identification in the table 
below.

Crankshaft pin

Connecting 
rod bearing

Identification 
mark

Journal diameter 
mm (in)

Identification 
mark

1

51.966 

− 51.972 

(2.0459 

− 2.0461)

1

2

51.960 

− 51.966 

(2.0457 

− 2.0459)

2

3

51.954 

− 51.960 

(2.0454 

− 2.0457)

3

2. An identification mark of a crankshaft is stamped at the 

illustrated position by No.

AK700793AD

Identification
mark

3. A connecting rod bearings an identification mark at the 

illustrated position.

.

>>F<< CONNECTING ROD CAP INSTALLATION 

AK703289AD

Cylinder 
number

Notch

1. Assemble the bearing cap on the connecting rod by aligning 

it with the mark put during removal. If a new connecting rod 
without a mating mark is used, assemble so that the detent 
notch of the bearing is on the same side as illustrated.

AK703364

PISTON AND CONNECTING ROD

TSB Revision

ENGINE OVERHAUL

11B-69

2. Make sure that clearance of the thrust of the connecting rod 

big end is appropriate.

Standard value: 0.10 

− 0.25 mm (0.004 − 0.010 inch)

Limit: 0.4 mm (0.02 inch)

.

>>G<< CONNECTING ROD CAP BOLT 
INSTALLATION

1. Check in the following procedure before reusing the 

connecting rod bolt.

AK604589AD

20.5 mm (0.81 in)

35 mm (1.38 in)

A

B

B

X

(1) Measure the outside diameter "A."
(2) Measure the smallest outside diameter "B" within the 

range "X" shown in the illustration.

(3) If the difference of outside diameter of thread exceeds 

the limit, replace the connecting rod bolt.

Limit: 0.10 mm (0.004 inch)

2. Apply engine oil to the threaded portion and seat surface of 

the bolt before installing it.

3. After installing each bolt and tightening it by fingers, tighten 

bolts alternately to properly assemble the cap.

4. Tighten the bolt in several steps until the torque reaches 5.0 

N

⋅ m (44 in-lb).

5. Tighten the bolt in several steps until the torque reaches 20 

N

⋅ m (15 ft-lb).

AK502749

90˚

Paint mark

AD

Paint mark

6. Put a paint mark on the bolt head as illustrated.
7. Put a paint mark on the connecting rod at 90

°  position in the 

tightening direction of the bolt with reference to the paint 
mark position of the bolt.

CAUTION

• When the tightening angle is smaller than the specified 

tightening angle, the appropriate tightening capacity 
cannot be secured.

• When the tightening angle is larger than the specified 

tightening angle, remove the bolt to start from the 
beginning again according to the procedure.

8. Tighten the bolt 90

° , and make sure that the paint mark of 

the connecting rod is aligned with that of the bolt.

PISTON AND CONNECTING ROD

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ENGINE OVERHAUL

11B-70

INSPECTION

M1113008501788

.

PISTON RINGS

AK502751

1. Check clearance between piston rings and ring grooves. If 

the limit is exceeded, replace piston rings or piston, or both.

Standard value:

No. 1 ring: 0.02 

− 0.06 mm (0.001 − 0.002 inch)

No. 2 ring: 0.02 

− 0.06 mm (0.001 − 0.002 inch)

Limit: 0.10 mm (0.004 inch)

AK603466

Please down ring 
with piston

End gap

Piston ring

AC

2. Put piston rings into the cylinder bore, press them against 

the piston top face, and push them in. After achieving 
squareness, measure the end gap with a thickness gauge. If 
the end gap is excessive, replace piston rings.

Standard value:

No. 1 ring: 0.18 

− 0.28 mm (0.007 − 0.011 inch)

No. 2 ring: 0.28 

− 0.43 mm (0.011 − 0.017 inch)

Oil ring: 0.10 

− 0.34 mm (0.004 − 0.013 inch)

Limit:

No. 1 ring: 0.8 mm (0.03 inch)
No. 2 ring: 0.8 mm (0.03 inch)
Oil ring: 1.0 mm (0.04 inch)

.

CRANKSHAFT PIN OIL CLEARANCE 
(PLASTIGAGE METHOD)

1. Wipe oil off the crankshaft pin and connecting rod bearing.
2. Place a plastigage in length equal to the bearing width on 

the pin shaft straight in alignment with the shaft center.

AK703363AC

Plastigage

3. Carefully install the connecting rod cap and tighten bolts to 

the specified torque of 5.0 N

⋅ m (44 in-lb) → 20 N⋅ m (15 

ft-lb) 

→ +90° .

4. Remove bolts and gently remove the connecting rod cap.