Subaru IMPREZA GD 2007 Series Manual page 2469

asieps_tobira_IM_US.book 68 ページ ２０１２年１月１７日 火曜日 午後３時４８分
MECHANICAL
3. VALVE GUIDE
1) Check the clearance between valve guide and
stem. The clearance can be checked by measuring
respectively the outer diameter of valve stem with a
micrometer and the inner diameter of valve guide
with a caliper gauge.
Clearance between the valve guide and valve
stem:
Standard:
Intake
0.030 — 0.057 mm (0.0012 — 0.0022 in)
Exhaust
0.040 — 0.067 mm (0.0016 — 0.0026 in)
Service limit:
0.15 mm (0.0059 in)
2) If the clearance between the valve guide and
stem exceeds the limit, replace the valve guide or
the valve itself, whichever shows greater amount of
wear. See the following procedure for valve guide
replacement.
Valve guide inner diameter:
6.000 — 6.012 mm (0.2362 — 0.2367 in)
Valve stem outer diameters:
Intake
5.955 — 5.970 mm (0.2344 — 0.2350 in)
Exhaust
5.945 — 5.960 mm (0.2341 — 0.2346 in)
(1) Place the cylinder head on ST1 with the
combustion chamber upward so that valve
guides fit the holes in ST1.
(2) Insert the ST2 into valve guide and press it
down to remove the valve guide.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499767200 VALVE GUIDE REMOVER
ST2
Cylinder Head
(3) Turn the cylinder head upside down and
place the ST as shown in the figure.
ST 18251AA020 VALVE GUIDE ADJUSTER
(4) Before installing a new valve guide, make
sure that neither scratches nor damages exist
on the inner surface of valve guide holes in cyl-
inder head.
(5) Put a new valve guide, coated with sufficient
oil, in the cylinder head, and insert the ST1 into
valve guide. Press in until the valve guide upper
end is flush with the upper surface of ST2.
ST1 499767200 VALVE GUIDE REMOVER
ST2 18251AA020 VALVE GUIDE ADJUSTER
ST1
ST2
(6) Check the valve guide protrusion.
Valve guide protrusion L:
15.8 — 16.2 mm (0.622 — 0.638 in)
(7) Insert the ST in valve guide, and rotate the
ST slowly clockwise while pushing it lightly.
Bring the ST back while rotating it clockwise.
ST 499767400
ST1
ME-00128
ME(H4DOTC)-68
ST
ME-00757
ME-00130
VALVE GUIDE REAMER
ME-00294