Intake And Exhaust Valve

WARNING: This page is about a different variant/trim than selected.

Check the flange and stem of the valve, and replace the valve with new one if damaged, worn, or deformed, "H" exceeds the standard, or if there is uneven wear.
Head edge thickness H:

Standard

Intake (A)

1.0 mm (0.039 in)

Exhaust (B)

1.2 mm (0.047 in)

Fig 1: Checking Intake And Exhaust Valve Head Edge Thickness
Courtesy of SUBARU OF AMERICA, INC.
Put a small amount of grinding compound on the valve seat surface, and lap the valve and valve seat surface. Install 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

103.5 mm (4.075 in)

Exhaust

103.2 mm (4.063 in)