Subaru IMPREZA GD 2007 Series Manual page 2470

asieps_tobira_IM_US.book 69 ページ ２０１２年１月１７日 火曜日 午後３時４８分
NOTE:
• Apply engine oil to the ST when reaming.
• If the inner surface of valve guide is damaged,
the edge of ST should be slightly ground with oil
stone.
• If the inner surface of valve guide becomes lus-
trous and the ST does not chip, use a new ST or
remedy the ST.
(8) After reaming, clean the valve guide to re-
move chips.
(9) Recheck the contact condition between
valve and valve seat after replacing the valve
guide.
4. INTAKE AND EXHAUST VALVE
1) Inspect the flange and stem of valve, and re-
place if damaged, worn, or deformed, or if "H" is
outside of the specified limit.
Head edge thickness H:
Standard:
Intake (A)
1.0 — 1.4 mm (0.039 — 0.055 in)
Exhaust (B)
1.3 — 1.7 mm (0.051 — 0.067 in)
Service limit:
0.8 mm (0.031 in)
Cylinder Head
2) Put a small amount of grinding compound on the
seat surface, and lap the valve and valve seat. In-
stall a new valve oil seal after lapping.
NOTE:
It is possible to differentiate between the intake
valve and the exhaust valve by their overall length.
Valve overall length:
Intake
104.4 mm (4.110 in)
Exhaust
104.65 mm (4.120 in)
5. VALVE SPRING
1) Check the valve springs for damage, free length,
and spring constant. Replace the valve spring if it is
not within standard values presented in the table.
Free length
Tension/spring
height
Squareness
2) To measure the squareness of the valve spring,
stand the spring on a surface plate and measure its
deflection at the top of spring using a try square.
ME-00758
ME(H4DOTC)-69
MECHANICAL
47.32 mm (1.863 in)
205 — 235 N (20.9 — 24.0 kgf,
Set 46.1 — 52.8 lbf) /36.0 mm
(1.417 in)
426 — 490 N (43.4 — 50.0 kgf,
Lift 95.8 — 110 lbf) /26.50 mm
(1.043 in)
2.5°, 2.1 mm (0.083 in) or less
ME-00132