Octane #

[dezwartj]

I am about to install a M62 blower on TC5061. Could any of you advise me on what number of octane in the gasoline I should use? Is it the higher # the better? Should I avoid gasoline with ethanol. (If possible)?

Thanks in advance,

Josh de Zwart

[Steve Simmons]

I would run high octane. The pressures under boost can be quite high, and detonation at these pressures can destroy an engine. I also prefer to run my supercharged engines a little rich for the same reason.

[Duncan M]

The distributor advance needs to be changed for supercharging. General rule is for full advance much sooner than normally aspirated.

[Ray White]

Does anyone know if an electronic distributor will "know" the difference?

[Steve Simmons]

Whether points or electronic, the distributor will only provide spark at a pre-determined moment in the engine's rotation. It won't know what fuel is in the car. There are knock sensors available for some EI systems that will automatically retard the timing if detonation occurs.