Infiniti G37 Coupe. Manual - part 632

CYLINDER HEAD

EM-103

< DISASSEMBLY AND ASSEMBLY >

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b.

Heat cylinder head to 110 to 130

°

C (230 to 266

°

F) by soaking in

heated oil (A).

c.

Using the valve guide drift (commercial service tool), press valve
guide (EXH) from camshaft side to the dimensions as shown in
the figure.

WARNING:

Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.

d.

Using the valve guide reamer (commercial service tool) (A),
apply reamer finish to valve guide (EXH).

2.

If valve seat (EXH) is removed in step 10 (DISASSEMBLY), install it. 
Replace with oversize [0.5 mm (0.020 in)] valve seat (EXH).

a.

Ream cylinder head recess diameter (a) for service valve seat
(EXH).

• Be sure to ream in circles concentric to valve guide center.

This will enable valve to fit correctly.

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Projection (A)

: Refer to 

EM-141, "Cylinder Head"

.

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Standard

: Refer to 

EM-141, "Cylinder Head"

.

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Oversize (service) [0.5 mm (0.020 in)]:

: Refer to 

EM-141, "Cylinder Head"

.

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EM-104

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CYLINDER HEAD

b.

Heat cylinder head to 110 to 130

°

C (230 to 266

°

F) by soaking in

heated oil (A).

c.

Provide valve seats (EXH) cooled well with dry ice. Force fit valve seat (EXH) into cylinder head.

WARNING:

Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.

CAUTION:

Avoid directly touching cold valve seats.

d.

Using the valve seat cutter set (commercial service tool) or valve
seat grinder, finish seat to the specified dimensions. Refer to

EM-141, "Cylinder Head"

.

CAUTION:

When using the valve seat cutter, firmly grip cutter handle
with both hands. Then, press on the contacting surface all
around the circumference to cut in a single drive. Improper
pressure on cutter or cutting many different times may
result in staged valve seat. 

e.

Using compound, grind to adjust valve fitting. 

f.

Check again for normal contact. Refer to "VALVE SEAT CONTACT".

3.

Install new cylinder head gaskets.

4.

Turn crankshaft until No. 1 piston is set at TDC.

• Crankshaft key should line up with the cylinder center line

(bank 1) as shown in the figure.

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SEM934C

1

: Crankshaft key

: Bank 1 side

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CYLINDER HEAD

EM-105

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5.

Install cylinder head, and tighten cylinder head bolts in numeri-
cal order as shown in figure as follows:

• Use the cylinder head bolt wrench [commercial service tool:

—  (J24239-01)] and power tool.

CAUTION:

• If cylinder head bolts are re-used, check their outer diam-

eters before installation. Refer to 

EM-106, "Inspection"

.

• Before installing cylinder head, inspect cylinder head dis-

tortion. Refer to 

EM-106, "Inspection"

.

a.

Apply new engine oil to threads and seat surfaces of cylinder
head bolts.

b.

Tighten all cylinder head bolts.

c.

Completely loosen all cylinder head bolts.

CAUTION:

In step “c”, loosen bolts in the reverse order of that indicated in the figure.

d.

Tighten all cylinder head bolts.

e.

Turn all cylinder head bolts 95 degrees clockwise (angle tighten-
ing).

CAUTION:

Check the tightening angle using the angle wrench [SST:
KV10112100 (BT8653-A)] (A). Never make judgment by
visual inspection.
• Check tightening angle indicated on the angle wrench indica-

tor plate.

f.

Turn all cylinder head bolts 95 degrees clockwise again (angle
tightening).

6.

After installing cylinder head, measure distance between front
end faces of cylinder block and cylinder head (bank 1 and bank
2).

• If measured value is out of the standard, re-install cylinder

head.

7.

Install new valve oil seals (EXH). Refer to 

EM-64, "VALVE OIL SEAL (EXH) : Removal and Installation"

.

8.

Install valve spring seat.

9.

Install valve.
NOTE:
Larger diameter valves are for intake side.

A

:  Bank  1

B

:  Bank  2

: Engine front

: 105 N·m (11 kg-m, 77 ft-lb)

: 0 N·m (0 kg-m, 0 ft-lb)

: 40.0 N·m (4.1 kg-m, 30 ft-lb)

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Standard

: 14.1 - 14.9 mm (0.555 - 0.587 in) 

EMQ0662D

EM-106

< DISASSEMBLY AND ASSEMBLY >

CYLINDER HEAD

10. Install valve spring (uneven pitch type).

• Install narrow pitch (B) end [paint mark (C)] to cylinder head

side (valve spring seat side).

11. Install valve spring retainer.

12. Install valve collet.

• Compress valve spring with the valve spring compressor [SST:

KV10116200 (J26336-A)] (A), the attachment [SST:
KV10115900 (J26336-20)] (C) and the adapter [SST:
KV10109220 (

—

)] (B). Install valve collet with a magnet

hand.

CAUTION:

When working, take care not to damage valve lifter holes.

• Tap valve stem edge lightly with plastic hammer after installa-

tion to check its installed condition.

13. Install valve lifter.

• Install it in the original position.

14. Install spark plug with spark plug wrench (commercial service tool).
15. Install in the reverse order of removal after this step.

Inspection

INFOID:0000000001547564

INSPECTION AFTER DISASSEMBLY

Cylinder Head Bolts Outer Diameter

• Cylinder head bolts are tightened by plastic zone tightening

method. Whenever the size difference between (B) and (A)
exceeds the limit, replace them with new one. 

• If reduction of outer diameter appears in a position other than (A),

use it as (A) point.

Cylinder Head Distortion

NOTE:
When performing this inspection, cylinder block distortion should be also checked. Refer to 

EM-120, "Inspec-

tion"

.

1.

Using a scraper, wipe off oil, scale, gasket, sealant and carbon deposits from surface of cylinder head.

CAUTION:

Never allow gasket fragments to enter engine oil or engine coolant passages.

A

: Wide pitch

: Cylinder head side

Paint mark color

Intake

: Purple

Exhaust

: Yellowish green

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Limit [(B) - (A)]

: 0.18 mm (0.0071 in)

c

: 48 mm (1.89 in)

d

: 11 mm (0.43 in)

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