Infiniti M45 (Y34). Manual - part 541

CYLINDER BLOCK

EM-101

C

D

E

F

G

H

I

J

K

L

M

A

EM

CAUTION:

If oversize piston is used, use it for all cylinders with oversize piston rings.

Outer Diameter of Piston

●

Measure the piston outer diameter with micrometer.

●

Measure point “H”(Distance from the top): 42 mm (1.65 in)

Piston to Cylinder Bore Clearance

●

Calculate by outer diameter of piston and inner diameter of cylinder bore (direction X, position B).

(Clearance) = (Inner diameter of cylinder bore) – (Outer diameter of piston)

●

If it exceeds the limit, replace piston/piston pin assembly. Refer to 

EM-90, "HOW TO SELECT PISTON"

 .

Reboring Cylinder Bore

1.

Cylinder bore size is determined by adding piston to cylinder bore clearance to piston outer diameter.

2.

Install main bearing caps, and tighten to the specified torque. Otherwise, cylinder bores may be distorted
in final assembly. Refer to 

EM-85, "ASSEMBLY"

 .

3.

Cut the cylinder bores.

NOTE:

●

When any cylinder needs boring, all other cylinders must also be bored.

●

Do not cut too much out of the cylinder bore at a time. Cut only 0.05 mm (0.0020in) or so in diameter at
a time.

4.

Hone cylinders to obtain specified piston to cylinder bore clearance.

5.

Measure the finished cylinder bore for out-of-round and taper.

NOTE:
Measurement should be done after the cylinder bore cools down.

Standard

: 92. 980 - 93. 010 mm (3.6606 - 3.6618 in)

PBIC0125E

PBIC0126E

Standard

: 0.010 - 0.030 mm (0.0004 - 0.0012 in)

Limit

: 0.08 mm (0.0031 in)

Rebored size calculation: D = A +B - C

where,

D: Bored diameter

A: Piston outer diameter as measured

B: Piston to cylinder bore clearance (standard value)

C: Honing allowance 0.02 mm (0.0008 in)

EM-102

CYLINDER BLOCK

CRANKSHAFT MAIN JOURNAL DIAMETER

●

Measure the outer diameter of crankshaft main journals with micrometer.

●

If out of standard, measure the main bearing oil clearance. Then use the undersize bearing. Refer to 

EM-

103, "OIL CLEARANCE OF MAIN BEARING"

 .

CRANKSHAFT PIN JOURNAL DIAMETER

●

Measure the outer diameter of crankshaft pin journal.

●

If out of standard, measure the connecting rod bearing oil clear-
ance. Then use the undersized bearing. Refer to 

EM-103, "OIL

CLEARANCE OF CONNECTING ROD BEARING"

 .

OUT-OF-ROUND AND TAPER OF CRANKSHAFT

●

Using a micrometer, measure the dimensions at 4 different
points shown in the figure on each journal and pin. 

●

Out-of-roundness is indicated by the difference in the dimension
between X and Y at A and B.

●

Taper is indicated by the difference in the dimension between A
and B at X and Y.

●

If the measured value exceeds the limit, correct or replace crankshaft.

●

If corrected, measure the bearing oil clearance of the corrected journal or pin. Then select main bearing or
connecting rod bearing. Refer to 

EM-103, "OIL CLEARANCE OF MAIN BEARING"

  and/or 

EM-103, "OIL

CLEARANCE OF CONNECTING ROD BEARING"

 .

CRANKSHAFT RUNOUT

●

Place a V-block on a precise flat table to support the journals on
the both end of crankshaft.

●

Place a dial indicator straight up on the No. 3 journal. 

●

While rotating crankshaft, read the movement of the pointer on
the dial indicator. (Total indicator reading) 

●

If it exceeds the limit, replace crankshaft.

Standard

: 63.940 - 63.964 mm (2.5173 - 2.5183 in)

Standard

: 51.956 - 51.974 mm (2.0455 - 2.0462 in)

PBIC0127E

Limit:

Out-of-round (Difference between “X” and “Y”)

: 0.015 mm (0.0006 in)

Taper (Difference between “A” and “B”)

: 0.010 mm (0.0004 in)

PBIC1685E

Limit:

: 0.10 mm (0.039 in)

PBIC2378E

CYLINDER BLOCK

EM-103

C

D

E

F

G

H

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EM

OIL CLEARANCE OF CONNECTING ROD BEARING
Method of Measurement

●

Install connecting rod bearings to connecting rod and cap, and
tighten the connecting rod nut to the specified torque. Refer to

EM-85, "ASSEMBLY"

  for the tightening procedure. 

●

Using a inside micrometer measure the inner diameter of con-
necting rod bearing.

(Oil clearance) = (Inner diameter of connecting rod bearing) –
(Crankshaft pin journal diameter)

●

If clearance exceeds the limit, select proper connecting rod
bearing according to connecting rod big end diameter and
crankshaft pin journal diameter to obtain specified bearing oil clearance. Refer to 

EM-91, "HOW TO

SELECT CONNECTING ROD BEARING"

 .

Method of Using Plastigage

●

Remove oil and dust on the crankshaft pin journal and the surfaces of each bearing completely. 

●

Cut a plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding
oil holes.

●

Install connecting rod bearings to connecting rod and connecting bearing cap, and tighten the connecting
rod nut to the specified torque. Refer to 

EM-85, "ASSEMBLY"

  for the tightening procedure. 

CAUTION:

Never rotate crankshaft.

●

Remove connecting rod cap and bearings, and using the scale
on the plastigage bag, measure the plastigage width. 

NOTE:
When the measured value exceeds the limit, the procedure is
same as that described in “Method of Measurement.”

OIL CLEARANCE OF MAIN BEARING
Method of Measurement

●

Install main bearings to cylinder block and main bearing cap.
Measure the main bearing inner diameter with the bearing cap
bolt tightened to the specified torque. Refer to 

EM-85, "ASSEM-

BLY"

  for the tightening procedure.

(Oil clearance) = (Inner diameter of main bearing) – (Outer diameter
of crankshaft main journal)

Standard

: 0.020 - 0.045 mm (0.0008 - 0.0018 in)

Limit

: 0.055 mm (0.0022 in)

PBIC1642E

SBIA0409E

PBIC1644E

Standard:

No. 1 and 5 journals

: 0.001 - 0.011 mm (0.00004 - 0.0004 in)

No. 2, 3, and 4 journals

: 0.007 - 0.017 mm (0.0003 - 0.0007 in)

Limit:

EM-104

CYLINDER BLOCK

●

If clearance exceeds the limit, select proper main bearing according to main bearing inner diameter and
crankshaft main journal diameter to obtain specified bearing oil clearance. Refer to 

EM-92, "HOW TO

SELECT MAIN BEARING"

 .

Method of Using Plastigage

●

Remove oil and dust on the crankshaft main journal and the surfaces of each bearing completely. 

●

Cut a plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding
oil holes

●

Install main bearings to cylinder block and main bearing cap, and tighten the main bearing bolts to the
specified torque. Refer to 

EM-85, "ASSEMBLY"

  for the tightening procedure.

CAUTION:

Never rotate crankshaft.

●

Remove bearing cap and bearings, and using the scale on the
plastigage bag, measure the plastigage width. 
NOTE:
When the measured value exceeds the limit, the procedure is
same as that described in “Method of Measurement”.

CRUSH HEIGHT OF MAIN BEARING

●

When the main bearing cap is removed after being tightened to
the specified torque with main bearings installed, the tip end of
bearing must protrude. Refer to 

EM-85, "ASSEMBLY"

  for the

tightening procedure.

●

If out of the standard, replace main bearings.

CRUSH HEIGHT OF CONNECTING ROD BEARING

●

When connecting rod bearing cap is removed after being tight-
ened to the specified torque with connecting rod bearings
installed, the tip end of bearing must protrude. Refer to 

EM-85,

"ASSEMBLY"

    for the tightening procedure.

●

If out of the standard, replace connecting rod bearings.

No.1 and 5 journals

: 0.021 mm (0.0008 in)

No. 2, 3, and 4 journals

: 0.027 mm (0.0011 in)

SBIA0410E

Standard

: There must be crush height.

SEM502G

Standard

: There must be crush height.

PBIC1646E