Nissan Primera P11. Manual — part 421
3.
Ream cylinder head valve guide bore.
Reaming bore (service part):
11.185 - 11.196 mm (0.4404 - 0.4408 in)
4.
Heat cylinder head to 150 to 160°C (302 to 320°F) and press
service valve guide onto cylinder head.
5.
Ream valve guide.
Final size:
7.000 - 7.015 mm (0.2756 - 0.2762 in)
VALVE SEATS
1.
Check valve and valve seat for contact.
Coat the valve face with prussian red lead. If contact is wrong,
correct valve seat. If the valve red lead appears 360° around
face, the valve stem and face are concentric. If not, repair or
replace valve.
2.
Check valve seats for pitting at contact surface. Resurface or
replace if excessively worn.
Correct valve seat surface.
When repairing valve seat, check valve and valve guide for
wear beforehand. If worn, replace them. Then correct valve
seat.
VALVE SEAT REPLACEMENT
1.
Bore out old seat until it collapses.
Set machine depth stop so that boring cannot contact bottom
face of seat recess in cylinder head.
2.
Ream the cylinder head recess.
Reaming bore for service valve seat
[Oversize 0.5 mm (0.020 in)]:
Intake 41.432 - 41.454 mm (1.6312 - 1.6320 in)
Exhaust 35.432 - 35.454 mm (1.3950 - 1.3958 in)
Use the valve guide center for reaming to ensure valve seat
will have the correct fit.
.
SEM245D
SEM246DA
10.3 mm
(0.406 in)
SEM722BA
SEM795A
Recess diameter
CYLINDER HEAD
CD20T
Inspection (Cont’d)
EM-143
3.
Heat cylinder head to a temperature of 150 to 160°C (302 to
320°F) and press fit seat until it seats on the bottom.
4.
Install valve seats.
When replacing valve seat, valve should be replaced as well.
5.
Cut or grind valve seat using a suitable tool at the specified
dimensions as shown in SDS (EM-198).
The cutting should be done with both hands to obtain a uni-
form and concentric finish.
6.
Apply a small amount of fine grinding compound to the valve’s
contacting face and put the valve into its guide.
Lap valve against its seat until proper valve seating is
obtained.
7.
Check valve seating condition.
VALVE DIMENSIONS
1.
Check dimensions of each valve. For dimensions, refer to SDS
(EM-197).
2.
Correct or replace any valve that is faulty.
SEM876
SEM877
SEM635AA
W: Refer to SDS.
SEM188A
T (Margin thickness)
CYLINDER HEAD
CD20T
Inspection (Cont’d)
EM-144
3.
Valve face or valve stem end surface should be refaced by
using a valve grinder.
When valve head has been worn down to 0.5 mm (0.020 in) in
margin thickness, replace the valve.
Grinding allowance for valve stem tip is 0.5 mm (0.020 in) or
less.
VALVE SPRING SQUARENESS
Check valve spring for squareness using a steel square and flat
surface plate.
If spring is out of square “S” more than specified limit, replace with
new one.
Out-of-square:
Outer
Less than 1.8 mm (0.071 in) — Intake —
Less than 2.2 mm (0.087 in) — Exhaust —
Inner
Less than 1.6 mm (0.063 in) — Intake —
Less than 1.8 mm (0.071 in) — Exhaust —
VALVE SPRING PRESSURE LOAD
Measure the free length and the tension of each spring. If the
measured value exceeds the specified limit, replace spring. Refer
to SDS (EM-197).
VALVE LIFTER
1.
Check contact and sliding surfaces for wear or scratches.
EM111
SEM333
EM113
SEM723B
CYLINDER HEAD
CD20T
Inspection (Cont’d)
EM-145
2.
Check diameter of valve lifters.
Outer diameter:
34.959 - 34.975 mm (1.3763 - 1.3770 in)
3.
Check valve lifter guide bore.
Bore diameter
34.998 - 35.018 mm (1.3779 - 1.3787 in)
Standard clearance
0.023 - 0.059 mm (0.0009 - 0.0023 in)
COMBUSTION CHAMBER REPLACEMENT
Usually combustion chambers should not be removed.
However, if they show cracks or extensive damage, they
should be replaced.
1.
Remove glow plug connecting plate, glow plugs and injection
nozzle.
2.
Heat cylinder head in oil to between 150 and 160°C (302 and
320°F).
3.
Remove combustion chamber so that cylinder head will not be
damaged.
Be careful not to scratch inside of nozzle hole.
4.
Install combustion chamber.
a.
Heat cylinder head 150 to 160°C (302 to 320°F) in oil.
b.
Align combustion chamber knock pin with cylinder head notch,
and install it into cylinder head using a plastic-tip hammer.
SEM724B
SEM725B
SEM720B
.
SEM721B
CYLINDER HEAD
CD20T
Inspection (Cont’d)
EM-146
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