Installing Valves

→ Remove all valve grinding paste fully after grinding.

Information 

• The valves cannot be touched up afterwards. 
• The valves can be ground using commercially available valve grinding paste. 

1. Apply a small amount of valve grinding paste to the valve seat.
2. Oil the valve stem of a new valve and insert it into the valve guide from the combustion chamber. Push the valve in until it is seated securely in the valve seat of the cylinder head.
3. Grind the valve with a commercially available valve grinder (with rubber suction head) using rotating movements. To do this, hold the valve grinder between the palms of both hands and press against the valve seat with rotating movements → Grinding valve seat  .
   Fig 1: Grinding Valve Seat

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
4. Carry out the grinding operation for each valve that is replaced. Check for leaks using some fuel and installed spark plugs. The fuel must not escape through the valve seat. Carefully remove valve grinding paste.
5. Fit valve lock. → Locking valves 
   Fig 2: Identifying Locking Valves

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
6. Replace valve stem seals. For details, see → 156355 REPLACING VALVE-STEM SEALS 
7. Fit valve springs, concave washers and valve keys. To do this, place valve springs (there are two in the outlet valve in the turbo engine) on the bottom concave washer. Place top concave washer in position.

   Information 

   The mechanic must practise for use of the assembly cartridge to be effective. Some repetitions must be made to ensure that the valve keys are correctly held in place.

8. Insert valve keys into the assembly cartridge.
   1. 8.1. Press the spring washer of the assembly fixture downwards -1-  and insert the valve keys -2-  with the narrow end pointing downwards.
      Fig 3: Inserting Valve Keys Into Assembly Cartridge

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   2. 8.2. Ensure that the valve keys fit symmetrically and are inserted as far as they will go in the tool. The spring washer automatically locks the valve keys in place.
   3. 8.3. Place the assembly cartridge -2-  onto the center of the assembly fixture. Observe installation position of the valve keys -1-  .
      Fig 4: Fitting Assembly Cartridge

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   4. 8.4. Press the assembly cartridge against the spring force onto the assembly fixture. The knurled screw moves forward. When doing so, turn the knurled screw back and forth until the valve keys snap into place. Repeat as required. → Assembly cartridge with valve keys 
      Fig 5: Pressing Assembly Cartridge Against Spring Force Onto Assembly Fixture

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   5. 8.5. Make sure the valve keys are held symmetrically in place in the assembly cartridge -1-  .
      Fig 6: Identifying Valve Keys In Assembly Cartridge

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
9. Place the valve key assembly cartridge onto the cylinder head (same as removal of valve) and position it on the top concave washer.
10. Press assembly cartridge with the lever (assembly bar) against the force of the valve spring and keep it pressed. The knurled screw moves forward. When doing so, turn the knurled screw back and forth until the valve keys snap into place → Installing valve keys  . Repeat as required.
    Fig 7: Installing Valve Keys

    Courtesy of PORSCHE CARS NORTH AMERICA, INC.
11. When installing the valve keys, check that they are positioned correctly.