Subaru 2002 IMPREZA Service Manual page 173

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CYLINDER HEAD ASSEMBLY
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 STI,
(3) Install the valve spring and retainer using
ST2.
ST1
498267600 CYLINDER HEAD TABLE
ST2 49971 8000 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 the 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 and
valve shim.
3) Install the valve lifter and valve shim.
E: INSPECTION
1. CYLINDER HEAD
1) Make sure that no crack or other damage exists.
In addition to visual inspection, inspect the impor-
tant 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:
Grinding limit:
Standard height of cylinder head:
CAUTION:
Uneven torque for the cylinder head nuts can
cause warping. When reassembling, pay spe-
cial attention to the torque so as to tighten
0.05 mm (0.0020 in)
0.3 mm (0.012 in)
127.5 mm (5.02 in)
evenly.
ME(D0HC TURBO)-67