Supra Liftback L6-2997cc 3.0L DOHC MFI Twin-Turbo (1997)
Valve Seat: Testing and Inspection
1. Apply a thin coat of prussian blue (or white lead) to the valve face. Lightly press the valve against the seat.
-
Do not rotate the valve.
2. Check the valve face and seat for the following:
-
If blue appears 360° around the face, the valve is concentric.
-
If not, replace the valve.
-
If blue appears 360° around the valve seat, the guide and face are concentric.
-
If not, resurface the seat.
-
Check that the seat contact is in the middle of the valve face with the following width:
-
Intake: 1.0-1.4 mm (0.0390-0.0550 inch).
-
Exhaust: 1.2-1.6 mm (0.0470-0.0630 inch).