Subaru 2009 IMPREZA Service Manual page 1132

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4. INTAKE AND EXHAUST VALVE

1) Inspect the flange of valve and valve stem, and

replace the valve with a new part if damaged, worn,

deformed, or if dimension "H" in the figure is out-

side of the specified limit.

Head edge thickness H:

1.0 — 1.4 mm (0.039 — 0.055 in)

1.3 — 1.7 mm (0.051 — 0.067 in)

2) Put a small amount of grinding compound on the

valve seat surface, and lap the valve and valve seat

surface. Replace with a new valve oil seal after lap-

It is possible to differentiate between the intake

valve and the exhaust valve by their overall length.

Valve overall length:

104.4 mm (4.110 in)

104.65 mm (4.1201 in)

Cylinder Head

5. VALVE SPRING

1) Check the valve springs for damage, free length,

and tension. Replace the valve spring if it is not

within the standard value presented in the table.

2) To measure the squareness of the valve spring,

stand the valve spring on a surface plate and mea-

sure its deflection at the top of the valve spring us-

ing a try square.

Tension/spring

N (kgf, lb)/mm (in)

ME(H4DOTC)-74

mm (in) 47.32 (1.863)

205 — 235 (20.9 — 24.0,

46.1 — 52.8)/36.0 (1.417)

426 — 490 (43.4 — 50.0,

95.8 — 110)/26.50 (1.041)

2.5°, 2.1 mm (0.083 in) or