Infiniti M45 (Y34). Manual - part 540

CYLINDER BLOCK

EM-97

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Refer to piston selection table to replace piston/piston pin assembly. Refer to 

EM-90, "HOW TO SELECT

PISTON"

 .

NOTE:

●

Piston is available together with piston pin as assembly.

●

Piston pin hole (piston pin) grade is provided only for the parts installed at the plant. For service parts,
no grades can be selected. (Only 0 grade is available.) 

PISTON RING SIDE CLEARANCE

●

Measure the side clearance of piston ring and piston ring groove
with feeler gauge.

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If out of the limit, replace piston and/or piston ring assembly.

PISTON RING END GAP

●

Check if the inner diameter of cylinder bore is within specification.
Refer to 

EM-100, "PISTON TO CYLINDER BORE CLEAR-

ANCE"

 .

●

Lubricate with new engine oil to piston and piston ring, and then
insert piston ring until middle of cylinder with piston, and mea-
sure piston ring end gap with feeler gauge.

●

If out of the limit, replace piston ring. If gap still exceeds the limit even with a new ring, re-bore cylinder
and use oversized piston and piston ring.

Standard:

Top ring

0.045 - 0.080 mm (0.0018 - 0.0031 in)

2nd ring

0.030 - 0.070 mm (0.0012 - 0.0028 in)

Oil ring

0.065 - 0.135 mm (0.0026 - 0.0053 in)

Limit:

Top ring

0.11 mm (0.0043 in)

2nd ring

0.10 mm (0.0039 in)

SEM024AA

Standard:

Top ring

0.22 - 0.32 mm (0.0087 - 0.0126 in)

2nd ring

0.22 - 0.32 mm (0.0087 - 0.0126 in)

Oil ring

0.20 - 0.50 mm (0.0079 - 0.0197 in)

Limit:

Top ring

0.56 mm (0.0220 in)

2nd ring

0.56 mm (0.0220 in)

Oil ring

0.86 mm (0.0339 in)

PBIC0118E

EM-98

CYLINDER BLOCK

CONNECTING ROD BEND AND TORSION

●

Check with connecting rod aligner.

●

If it exceeds the limit, replace connecting rod assembly.

CONNECTING ROD BIG END DIAMETER

●

Install connecting rod cap without connecting rod bearing
installed. After tightening the connecting rod nut to the specified
torque. Refer to 

EM-85, "ASSEMBLY"

  for the tightening proce-

dure.

●

Measure the connecting rod big end diameter using an inside
micrometer.

●

If it exceeds the standard, replace connecting rod.

CONNECTING ROD BUSHING OIL CLEARANCE
Inner Diameter of Connecting Rod Bushing

Measure the inner diameter of connecting rod bushing with inside
micrometer.

Bend:

Limit 0.15 mm (0.0059 in) per 100 mm (3.94 in) length

Torsion:

Limit 0.30 mm (0.0118 in) per 100 mm (3.94 in) length

PBIC2077E

Standard

: 55.000 - 55.013 mm (2.1654 - 2.1659 in)

PBIC1641E

Standard

: 22.000 - 22.012 mm (0.8661 - 0.8666 in)

PBIC0120E

CYLINDER BLOCK

EM-99

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Outer Diameter of Piston Pin

Measure the outer diameter of piston pin with micrometer.

Connecting Rod Bushing Oil Clearance

(Connecting rod bushing oil clearance) = (Inner diameter of connecting rod bushing) – (Outer diameter of pis-
ton pin)

●

If the measured value exceeds the standard, replace connecting rod assembly and/or piston/piston pin
assembly.

●

If replacing piston and piston pin assembly, refer to 

EM-100, "PISTON TO CYLINDER BORE CLEAR-

ANCE"

 .

●

If replacing connecting rod assembly, refer to 

EM-103, "OIL

CLEARANCE OF CONNECTING ROD BEARING"

      to  select

the connecting rod bearing.

Factory installed parts grading:
Service parts apply only to grade “0”.

Unit: mm (in)

CYLINDER BLOCK DISTORTION

●

Using a scraper, remove gasket on the cylinder block surface, and also remove engine oil, scale, carbon,
or other contamination. 

CAUTION:

Be careful not to allow gasket flakes to enter the engine oil or engine coolant passages.

Standard

: 21.989 - 22.001 mm (0.8657 - 0.8662 in)

PBIC0117E

Standard

: 0.005 - 0.017 mm (0.0002 - 0.0007 in)

PBIC2164E

               Grade

                    0

                    1

Connecting rod bushing 
inner diameter

         22.000 - 22.006          
       (0.8661 - 0.8664)

         22.006 - 22.012
        (0.8664 - 0.8666)

Piston pin outer diameter

        21.989 - 21.995
       (0.8657 - 0.8659)

         21.995 - 22. 001
        (0.8659 - 0.8662)

Piston pin bore diameter

        21.993 - 21.999
       (0.8659 - 0.8661)

         21.999 - 22.005
        (0.8661 - 0.8663)

PBIC2372E

EM-100

CYLINDER BLOCK

●

Measure the distortion on the block upper face at some different
points in 6 directions.

●

If out of the limit, replace cylinder block.

INNER DIAMETER OF MAIN BEARING HOUSING

●

Install main bearing caps with main bearings removed, and
tighten the mounting bolts to the specified torque. Refer to 

EM-

85, "ASSEMBLY"

  for the tightening procedure.

●

Using a bore gauge, measure the inner diameter of the main
bearing housing. 

●

If out of the standard, replace the cylinder block and main bear-
ing caps as an assembly. 

NOTE:
These components cannot be replaced as a single unit, because
they were processed together.

PISTON TO CYLINDER BORE CLEARANCE
Inner Diameter of Cylinder Bore

●

Using a bore gauge, measure the cylinder bore diameter for
wear, out-of-round and taper at 6 different points on each cylin-
der. (X and Y directions at A, B and C)

NOTE:
When determining cylinder bore grade, measure cylinder bore at B
position.

●

If the measured value exceeds the limit, or if there are scratches
and/or seizure on the cylinder inner wall, hone or bore the inner wall. 

●

Oversize piston is provided. When using oversize piston, hone cylinder so that the clearance between pis-
ton and cylinder satisfies the standard.

Limit

: 0.1 mm (0.004 in)

SEM123C

Standard

: 68.944 - 68.968 mm (2.7143 - 2.7153 in)

PBIC1643E

PBIC0123E

Standard inner diameter:

 93.000 - 93.030 mm (3.6614 - 3.6626 in)

Wear limit:

 0.20 mm (0.0079 in)

Out-of-round (Difference between X and Y):

 0.015 mm (0.0006 in)

Taper limit (Difference between A and C):

 0.010 mm (0.0004 in)

Oversize (OS)

: 0.2 mm (0.008 in)

PBIC0124E