Valve technology

The tough life of a valve

The valve – a small piece with a lot of stress:

  • exposed to up to 1‘000 degC and corrosive exhaust gases such as CO, NOx and HCx
  • opens and closes 50 times / second when the engine is turning at 6000 rpm.
  • opens and closes 300‘000‘000 times over the typical life of a cylinder head (200‘000 km)
  • the valve of a high-performance motorcycle engine turning at 12‘000 rpm moves within 1.8 milliseconds from the fully open to the fully closed position
  • the combustion pressure in a modern engine can easily each 80 bar, which is comparable to an 800 kg sledgehammer beating on the seat of a valve with a diameter of 36 mm.