Valve seats

Fig 1: Identifying Valve Seats

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Use a cutter set with T-wrench  83 95 204, VALVE SEAT CUTTER  83 93 936 (60°) and VALVE SEAT CUTTER  78 61 040 (45).

Valve seat angles, inlet and exhaust valves: 45°.

Regrinding angle: 60°.

Valve seat width: Inlet valve 1.0-1.5 mm.

Outlet valve 1.5-2.0 mm

Press home the guide spindle into the valve guide from the valve seat side. Cut clean the valve seats in the cylinder head with a 45° cutter. It may be necessary to remove the hard surface on the exhaust valve seat with an abrasive cloth. In most cases, the valve seat width will be too great after cutting and must be reduced. Use a 60° correction cutter to reduce the width.

Apply a thin layer of grinding paste on the valve seat and insert the valve into the cylinder head. The grinding paste must not come in contact with the valve stem. Rotate with the grinding tool a few times. Clean off the grinding paste thoroughly and check the contact surface with e.g. marking ink. Repeat the grinding where required and recut if necessary.