Installing Cylinder Head

Information 

If cold or excessively low-tempered components are sealed to each other by applying sealant, leaks can occur because of condensed water forming or components distorting. Components must be uniformly at least → Temperature: 17°C.

1. Install cylinder head.
   Fig 1: Identifying Cylinder Head Screws Tightening Sequence

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   1. 1-6 - Pistons of cylinders 1 - 6
   2. 1-20 - Tightening sequence for cylinder-head screws → Initial tightening: 15 Nm (11 ft lbs.)  → Tightening torque: 30 Nm (22 ft lbs.)  → Torque angle: 180° 

   Information 

   • It is best to use only a spatula and acetone to clean the sealing faces. Ensure good ventilation because of the acetone! 
   • Use a cleaning cloth to wipe the sealing faces clean and remove any grease. 
   • Replace the cylinder-head gasket. 
   • Replace the cylinder-head screws with new ones. 
   1. 1.1. Thoroughly clean all sealing faces before assembly.
   2. 1.2. Cylinder head gasket must always be replaced  .
   3. 1.3. Always observe tightening sequence (1-20) for cylinder-head screws -1 to 20-  and tighten to the specified torque.
   4. 1.3.1. Tighten cylinder-head screws to an initial tightening torque of 15 Nm (11 ft lbs.).
   5. 1.3.2. Tighten cylinder-head screws to 30 Nm (22 ft lbs.).
   6. 1.3.3. Then tighten all cylinder-head screws a second time  to 30 Nm (22 ft lbs.).
   7. 1.3.4. And finally, tighten the cylinder-head screws to a torque angle of 180°.
2. Secure the timing case to the cylinder head. -1-  Fit both M8 screws → Tightening torque: 23 Nm (17 ft lbs.). 
   Fig 2: Identifying Lower Timing-Case Cover Screws

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.