Octane and Grade

[Nynjazen]

Hi,

Does anybody know what this specification means:

- Octane 100 Grade 100/130 for instance for Napier Sabre Engine series of the hawker Tempest or RR Griffon for the late WW2 Spitfire ?

Thanks a lot
Nynjazen

 

[stona]

The two numbers are both octane ratings associated with the Motor Octane Number (MON) of the fuel. The first number indicates the octane rating of the fuel tested to "aviation lean" standards, which is similar to the anti-knock index or "pump rating" given to the petrol (gasoline) which you can buy for your car.The second number indicates the octane rating of the fuel tested to the "aviation rich" standard, which tries to simulate a supercharged condition with a rich mixture, elevated temperatures, and a high manifold pressure.
Cheers
Steve

 

[Nynjazen]

Hi Steeve,

Thanks a lot
Have a good day,
Nynjazen