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Engine Compression Calculator

Calculez le taux de compression théorique d’un moteur à partir de l’alésage, de la course et du volume de la chambre.

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Compression ratio basics

Compression ratio = (swept volume + clearance volume) ÷ clearance volume. It tells how much the fuel-air charge is squeezed before ignition.

  • Typical petrol engines : 9.0:1 to 12.5:1
  • Turbo petrol engines : 8.5:1 to 10.5:1 (boost needs lower static ratio)
  • Diesels : 16:1 to 22:1
  • Higher ratio = more efficiency and torque, but requires higher-octane fuel

FAQ

Oui, mais il faut respecter l’indice d’octane et les jeux soupapes/piston. Au-delà, risque de cliquetis.
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