av gas

[nutup]

does anyone know if aviation gas is oxgenated? I have ran it and had better 60 ft times than with sunoco 112. just curios if anyone might know or maybe this was a fluke that it ran better. I went back to the 112 and my time fell off

[fla1976]

AVGAS is usually 100 Octane. If your car slowed, it may be that your engine does not require 112 octane. What compression ratio are you running? A higher octane rating means the burn rate of the fuel is slower. A slower burn allows a more time to burn to prevent detonation. If your engine doesn't needing it , you can lose power.

[jmarksdragster]

Not exactly true, the rating is a resistance to detonation, not burn speed. A higher octane may actually burn faster. Gas is a mix of hydrocarbon compounds, some evaporate early and some late. To give you an example, Track Tek 114 has an initial boiling point of 110˚ and a 100% evaporated point of 300˚. Track Tek 118, a higher octane, also starts at 110˚ but ends earlier at 250˚. There are also differences in specific gravity of fuels, which usually require a change in tuneup. When we ran it years ago, it liked to be a little richer than race fuel, if you are too rich with race gas it might explain it.

[chevyfireball]

I'd say its the specific gravity thats the difference. Check out specific gravity on Google and it'll explain it best about needing bigger or smaller jets depending on the specific gravity.