Nissan Primera P11. Instruction — part 409
VALVE SEATS
Check valve seats for any evidence of pitting at valve contact sur-
face. Reset or replace if it has worn out excessively.
I
Before repairing valve seats, check valve and valve guide
for wear. If they have worn, replace them. Then correct
valve seat.
I
Use both hands to cut uniformly.
REPLACING VALVE SEAT FOR SERVICE PARTS
1.
Bore out old seat until it collapses. Boring should not continue
beyond the bottom face of the seat recess in cylinder head. Set
the machine depth stop to ensure this.
2.
Ream cylinder head recess.
Reaming bore for service valve seat
Oversize [0.5 mm (0.020 in)]:
Intake
35.500 - 35.516 mm (1.3976 - 1.3983 in)
Exhaust
31.500 - 31.516 mm (1.2402 - 1.2408 in)
Be sure to ream in circles concentric to the valve guide cen-
ter. This will enable valve seat to fit correctly.
3.
Heat cylinder head to 110 to 130°C (230 to 266°F).
4.
Press fit valve seat until it seats on the bottom.
5.
Cut or grind valve seat using a suitable tool at the specified
dimensions as shown in SDS (EM-190).
6.
After cutting, lap valve seat with abrasive compound.
7.
Check valve seating condition.
Seat face angle “
α
”:
44°53
′
- 45°07
′
Contacting width “W”:
Intake
1.385 - 1.401 mm (0.0545 - 0.0552 in)
Exhaust
1.385 - 1.401 mm (0.0545 - 0.0552 in)
VALVE DIMENSIONS
Check dimensions in each valve. For dimensions, refer to SDS
(EM-189).
When valve head has been worn down to 0.5 mm (0.020 in) in
margin thickness, replace valve.
Grinding allowance for valve stem tip is 0.2 mm (0.008 in) or
less.
SEM934C
SEM795A
.
Recess diameter
SEM008A
Oil
SEM892B
.
SEM188A
T (Margin thickness)
CYLINDER HEAD
SR20DE
Inspection (Cont’d)
EM-95
VALVE SPRING
Squareness
1.
Measure “S” dimension.
Out-of-square:
Less than 2.2 mm (0.087 in)
2.
If it exceeds the limit, replace spring.
Free height
Check free height: 49.36 mm (1.9433 in)
Pressure
Check valve spring pressure.
Pressure: N (kg, lb) at height mm (in)
Standard
519 - 571 (52.9 - 58.2, 116.6 - 128.3) at 27 (1.063)
Limit
Replace if load is less than 501 (51.1 - 112.7) at
27 (1.063)
HYDRAULIC LASH ADJUSTER
1.
Check contact and sliding surfaces for wear or scratches.
2.
Check diameter of lash adjuster.
Outer diameter:
16.980 - 16.993 mm (0.6685 - 0.6690 in)
3.
Check lash adjuster guide inner diameter.
Inner diameter:
17.000 - 17.020 mm (0.6693 - 0.6701 in)
Standard clearance between lash adjuster and
adjuster guide:
0.007 - 0.040 mm (0.0003 - 0.0016 in)
SEM288A
S (Out-of-square)
EM113
SEM935C
SEM936C
.
SEM084D
CYLINDER HEAD
SR20DE
Inspection (Cont’d)
EM-96
ROCKER ARM, SHIM AND ROCKER ARM GUIDE
Check contact and sliding surfaces of rocker arms, shims and
rocker arm guides for wear or scratches.
Assembly
1.
Install intake manifold.
2.
Install thermostat housing with water pipe.
I
Tightening procedure:
1)
Tighten bolt
p
A
to 2 - 5 N·m (0.2 - 0.5 kg-m, 1.4 - 3.6 ft-lb).
2)
Tighten bolt
p
C
to 16 - 21 N·m (1.6 - 2.1 kg-m, 12 - 15 ft-lb).
3)
Tighten bolt
p
A
to 16 - 21 N·m (1.6 - 2.1 kg-m, 12 - 15 ft-lb).
4)
Tighten bolt
p
B
to 16 - 21 N·m (1.6 - 2.1 kg-m, 12 - 15 ft-lb).
3.
Install exhaust manifold.
4.
Install exhaust manifold cover.
5.
Install water outlet.
a.
Before installing water outlet, remove all traces of liquid gas-
ket from mating surface using a scraper.
I
Also remove traces of liquid gasket from mating surface of
cylinder head.
b.
Apply a continuous bead of liquid gasket to mating surface of
water outlet.
I
Use Genuine Liquid Gasket or equivalent.
6.
Install valve component parts.
I
Install valves with larger diameter head on the intake side.
NEM144
Bearing surface
Rocker arm
Shim
Rocker arm guide
SEM064G
Tighten in numerical order.
NEM216
Thermostat
housing
Water pipe
SEM059GA
Tighten in numerical order.
SEM086D
2.0 - 3.0 mm
(0.079 - 0.118 in)
Liquid gasket
CYLINDER HEAD
SR20DE
Assembly
EM-97
I
Always use new valve oil seal.
Refer to OIL SEAL REPLACEMENT.
I
Before installing valve oil seal, install valve spring seat.
I
Install valve spring (uneven pitch type) with its narrow
pitched side toward cylinder head side (paint mark).
I
After installing valve component parts, tap valve stem tip
with plastic hammer to assure a proper fit.
7.
Check hydraulic lash adjusters.
a.
Push rocker arm at hydraulic lash adjuster location, and see if
rocker arm moves. If it moves at least 1 mm (0.04 in), it indi-
cates that there is air in the high pressure chamber.
Noise will be emitted from hydraulic lash adjuster if engine is
started without bleeding air.
b.
Remove hydraulic lash adjuster and dip in a container filled
with engine oil. While pushing plunger as shown in figure,
lightly push check ball using a thin rod. Air is completely bled
when plunger no longer moves.
Air cannot be bled from this type of lash adjuster by running
the engine.
8.
Install rocker arms, shims, rocker arm guides and hydraulic
lash adjusters.
CAUTION:
Install all parts in their original positions.
9.
Select a suitable shim when replacing any of the following
parts with a new one: Cylinder head, shim, rocker arm guide
and valve seat. Proceed as follows to select the shim of cor-
rect thickness.
a.
Install valve component parts to cylinder head (Except shim).
I
Always replace rocker arm guide with a new one.
SEM085D
Wide pitch
Narrow pitch
Paint mark
Cylinder head side
NEM146
Push
NEM147
Rod
Engine oil
SEM202D
Rocker arm guide
Rocker arm
Shim
Hydraulic
lash adjuster
SEM364D
Shim
Rocker arm guide
Valve collet
Valve spring
retainer
Valve spring
Valve spring seat
Valve oil seal
Valve
CYLINDER HEAD
SR20DE
Assembly (Cont’d)
EM-98
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