During normal combustion there is only one flame front which advances from the spark plug to the outer edges of the combustion chamber. During abnormal combustion multiple flame fronts can start, which leads to detonation. Flame Speed is a function of fuel chemistry, and engine design . The component make up of a racing fuel will influence the burn time whether it's a high octane fuel or not. Hydrocarbons - The building blocks of gasoline made up of chemical compounds consisting of hydrogen and carbon atoms only .
Gasoline is made up of a combination hydrocarbons with different molecular weights and structure.
The various components that make up gasoline are classified according to the number of carbon atoms in the molecules. These components form chemical groups called Aromatics, Paraffins, and Olefins. Aromatics are the components that most people are familiar with. They include compounds like Toluene, Benzene, Aniline, Benzene, and Xylene among others. They are commonly used to increase octane and to raise BTU content.