Detonation

It is caused by the fuel with a low octane rating and is the tendency for the fuel to autoignite in an engine combustion chamber.
The resulting knock or ping is the sound of the pistons slamming against the cylinder walls. Severe detonation can break pistons and destroy engines.
This early ignition of fuel creates a shock wave throughout the cylinder as the burning and expanding fuel air mixture collides with the piston that is still traveling towards T.D.C. (top dead center) .

Filed Under: Automobile Engineering, Detonation, Mechanical Engineering on Monday, May 27, 2013