Component Overview

In the Turbo, the exhaust valve is fitted with internal and external valve springs (set of valve springs) and adapted concave washers. The exhaust valve in the turbo engine has the same outer dimensions as the exhaust valve of the naturally aspirated engine. However, because of the sodium filling, the exhaust valve in the turbo engine is lighter and the shank over the shank entries is longer. For further details, please see Figures and Table entitled " VALVE DIMENSIONS  ". 

Fig 1: Exploded View Of Valves (Turbo Cylinder Bank 5 To 8)

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

1. Intake valve (identical in the naturally aspirated and turbo engines)
2. Valve-seat ring intake
3. Valve guide
4. Lower valve-spring plate intake
5. Valve stem seal
6. Set of valve springs, intake (identical in the naturally aspirated and turbo engines)
7. Upper valve-spring plate intake
8. Valve collet
9. Upper valve-spring plate outlet (different in the naturally aspirated and turbo engines)
10. Set of valve springs (turbo outlet); valve spring (naturally aspirated engine outlet)
11. Lower valve-spring plate outlet (different in the naturally aspirated and turbo engines)
12. Valve-seat ring outlet
13. Exhaust valve (different in the naturally aspirated and turbo engines)

Distinguishing feature of exhaust valve on naturally aspirated and turbo engine

1. Exhaust valve - naturally aspirated engine
2. Exhaust valve - turbo engine
3. Difference in shank length over shank entries
   Fig 2: Identifying Difference Between Exhaust Valve On Naturally Aspirated And Turbo Engine

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.