Enter engine displacement here.

Number of cylinders of engine.

Enter the speed at which the maximum power is reached - this is not the maximum engine speed. Please be realistic to get best results.

Count of carburetors you will use. Usually one carburetor feeds two cylinders, but it can also feed four cylinders.

This is good option for oldtimers, for cars you use for fun without reving it too much. If you like to shift under 6000RPM, this is your choice.

This is good option for hill climbs, racing on circuit, for all cars with custom gearbox and special camshafts. When you have to rev the engine to get power from it, like shifting at 8000RPM, this is definitely your choice.