Infiniti F50. Manual - part 550

CYLINDER BLOCK

EM-87

Use Undersize Bearing Usage Guide

●

Use undersize (US) bearing when oil clearance with standard size main bearing is not within specification.

●

When using undersize (US) bearing, measure inner diameter of bearing installed and grind journal until oil
clearance falls within specification.

Bearing undersize table

Unit: mm (in)

CAUTION:

Do not damage fillet R when grinding crankshaft journal in
order to use undersized bearing (All journals).

Inspection After Disassembly

EBS002MX

CRANKSHAFT END PLAY

●

Using a dial gauge, measure the clearance between the thrust
bearings and the crankshaft arm when the crankshaft is moved
fully forward or backward.

●

If the measured value exceeds the repair limit, replace the thrust
bearings, and measure again. If it still exceeds the repair limit,
replace the crankshaft also.

UPR

2.483 - 2.486 (0.0978 - 0.0979)

Black/Brown

Grade and color are different
for upper and lower bearings.

LWR

2.486 - 2.489 (0.0979 - 0.0980)

UPR

2.486 - 2.489 (0.0979 - 0.0980)

Brown/Green

LWR

2.489 - 2.492 (0.0980 - 0.0981)

UPR

2.489 - 2.492 (0.0980 - 0.0981)

Green/Yellow

LWR

2.492 - 2.495 (0.0981 - 0.0982)

UPR

2.492 - 2.495 (0.0981 - 0.0982)

Yellow/Blue

LWR

2.495 - 2.498 (0.0982 - 0.0983)

UPR

2.495 - 2.498 (0.0982 - 0.0983)

Blue/Pink

LWR

2.498 - 2.501 (0.0983 - 0.0985)

UPR

2.498 - 2.501 (0.0983 - 0.0985)

Pink/Purple

LWR

2.501 - 2.504 (0.0985 - 0.0986)

UPR

2.501 - 2.504 (0.0985 - 0.0986)

Purple/White

LWR

2.504 - 2.507 (0.0986 - 0.0987)

UPR

2.504 - 2.507 (0.0986 - 0.0987)

White/Red

LWR

2.507 - 2.510 (0.0987 - 0.0988)

Size

Thickness

US 0.25 (0.0098)

2.618 - 2.626 (0.1031 - 0.1034)

PBIC0111E

Standard

: 0.10 - 0.25 mm (0.0039 - 0.0098 in)

Limit

: 0.30 mm (0.0118 in)

PBIC0114E

EM-88

CYLINDER BLOCK

CONNECTING ROD SIDE CLEARANCE

●

Measure side clearance between connecting rod and crankshaft
arm with feeler gauge.

●

If the measured value exceeds the repair limit, replace the con-
necting rod bearings, and measure again. If it still exceeds the
repair limit, replace the crankshaft also.

PISTON AND PISTON PIN CLEARANCE
Inner Diameter of Piston Pin

Measure the inner diameter of piston pin bore with an insidemi-
crometer.

Outer Diameter of Piston Pin

Measure outer diameter of piston pin with a micrometer.

Piston and Piston Pin Clearance

(Piston pin clearance) = (Piston pin bore diameter) – (Outer diameter
of piston pin)

●

If clearance is exceeds specification, replace either or both of
piston/piston pin assembly and connecting rod assembly with
reference to specification of each parts.

●

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

EM-82, "HOW TO SELECT PISTON"

●

Refer to connecting rod bearing selection table to replace con-
necting rod. Refer to

EM-83, "HOW TO SELECT CONNECTING

ROD BEARING"

Standard

: 0.20 - 0.35 mm (0.0079 - 0.0138 in)

Limit

: 0.40 mm (0.0157 in)

PBIC0115E

Standard

: 21.993 - 22.005 mm (0.8659 - 0.8663 in)

PBIC0116E

Standard

: 21.989 - 22.001 mm (0.8657 - 0.8662 in)

PBIC0117E

Standard

: 0.002 - 0.006 mm (0.0001 - 0.0002 in)

PBIC0109E

CYLINDER BLOCK

EM-89

NOTE:

●

The connecting rod small end grade and piston pin hole (pis-
ton pin) grade are provided only for the parts installed at the
plant. For service parts, no grades can be selected. (Only 0
grade is available.)

●

Refer to

EM-91, "Connecting Rod Bushing Oil Clearance (Small

End)"

for the values for each grade at the plant.

PISTON RING SIDE CLEARANCE

●

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

●

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

PISTON RING END GAP

●

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

EM-93, "Piston to Cylinder Bore Clearance"

●

Insert piston ring until middle of cylinder with piston, and mea-
sure gap.

●

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

PBIC0103E

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 - 0.60 mm (0.0079 - 0.0236 in)

Limit:

Top ring

0.56 mm (0.0220 in)

2nd ring

0.52 mm (0.0205 in)

Oil ring

0.96 mm (0.0378 in)

PBIC0118E

EM-90

CYLINDER BLOCK

CONNECTING ROD BEND AND TORSION

●

Check with connecting rod aligner.

●

If it exceeds the limit, replace connecting rod assembly.

CONNECTING ROD BEARING (BIG END)

Install the connecting rod cap without the connecting rod bearing
installed. After tightening the connecting rod nut to the specified
torque, measure the connecting rod large end inner diameter using
an inside micrometer.

CONNECTING ROD BUSHING OIL CLEARANCE (SMALL END)
Inner Diameter of Connecting Rod (Small End)

Measure inner diameter of bushing.

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

SEM003F

SEM038F

Standard

: 55.000 - 55.013 mm (2.1654 - 2.1659 in)

PBIC0119E

Standard

: 22.000 - 22.012 mm (0.8661 - 0.8666 in)

PBIC0120E

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