Cylinder Head - Subaru Impreza 2002 Service Manual

MECHANICAL
1) Installation of valve spring and valve:
(1) Coat the stem of each valve with engine oil
and insert the valve into valve guide.
CAUTION:
When inserting the valve into valve guide, use
special care not to damage the oil seal lip.
(2) Set the cylinder head on ST1.
(3) Install the valve spring and retainer using
ST2.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499718000 VALVE SPRING REMOVER
CAUTION:
Be sure to install the valve springs with their
close-coiled end facing the seat on the cylinder
head.
(4) Compress the valve spring and fit valve
spring retainer key.
(5) After installing, tap the valve spring retainers
lightly with wooden hammer for better seating.
2) Apply oil to the surface of the valve lifter.
3) Install the valve lifter.
E: INSPECTION

1. CYLINDER HEAD

1) Make sure that no crack or other damage exists.
In addition to visual inspection, inspect important
areas by means of red check.
2) Measure the warping of the cylinder head sur-
face that mates with crankcase by using a straight
edge (A) and thickness gauge (B).
If the warping exceeds 0.05 mm (0.0020 in), re-
grind the surface with a surface grinder.
Warping limit:
0.05 mm (0.0020 in)
Grinding limit:
0.1 mm (0.004 in)
Standard height of cylinder head:
127.5 mm (5.02 in)
CYLINDER HEAD ASSEMBLY
S2M1881A
ME(STi)-68
CAUTION:
Uneven torque for the cylinder head nuts can
cause warping. When reassembling, pay spe-
cial attention to the torque so as to tighten
evenly.
2. VALVE SEAT
Inspect intake and exhaust valve seats, and correct
the contact surfaces with valve seat cutter if they
are defective or when valve guides are replaced.
Valve seat width: W
Intake
Standard
1.0 mm (0.039 in)
Limit
1.7 mm (0.067 in)
Exhaust
Standard
1.5 mm (0.059 in)
Limit
2.2 mm (0.087 in)
S2M1840A
G2M0761