Subaru Impreza 2002 Service Manual page 4155

MECHANICAL
(8) 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
less than the specified limit.
H:
Intake
Standard
1.2 mm (0.047 in)
Limit
0.8 mm (0.031 in)
Exhaust
Standard
1.5 mm (0.059 in)
Limit
0.8 mm (0.031 in)
Valve overall length:
Intake
104.4 mm (4.110 in)
Exhaust
104.7 mm (4.122 in)
2) Put a small amount of grinding compound on the
seat surface and lap the valve and seat surface. In-
stall a new intake valve oil seal after lapping.
CYLINDER HEAD ASSEMBLY
ME(STi)-70
5. VALVE SPRINGS
1) Check valve springs for damage, free length,
and tension. Replace the valve spring if it is not
within the specifications presented in the table.
2) To measure the squareness of the valve spring,
stand the spring on a surface plate and measure its
deflection at the top using a try square.
Valve spring
Free length 44.67 mm (1.7587 in)
220.7±15.7 N
(22.5 ± 1.6 kgf, 49.6±3.5 lb)/36.0 mm
(1.417 in)
Tension/spring
height
582±29 N
(59.3±3.0 kgf, 130.8±6.6 lb)/26.45
mm (1.041 in)
Squareness 2.5°, 1.9 mm (0.075 in)