What is detonation, or pinging?
A. Detonation (or pinging or engine knock) occurs simply when fuel pre-ignites before the piston reaches top dead center. This means that a powerful explosion is trying to expand a cylinder chamber that is shrinking in size, attempting to reverse the direction of the piston and the engine. When detonation occurs, the internal pneumatic forces can actually exceed 10x the normal forces acting upon a properly operating high performance engine. Detonation is generally caused by excessive heat, excessive boost pressure, improper ignition timing, inadequate fuel octane, too lean of an air/fuel ratio, or a combination of these. Of the previous, excessive boost and/or too lean of an air/fuel mixture is usually the culprit. Today’s premium pump gas has a compression tolerance of around 13:1 to 14:1, and todays high compression engines start with around a 10:1 compression ratio, This limits boost potential unless changes and/or compromises are made in other areas of engine management. In additio
Pinging, knocking or detonation are terms for a rattling sound that emanates from the engine when under load and sounds like nuts/bolts rattling around in a hubcap. It is the sound of destructive, abnormal combustion and severely shocks the conrods, pistons and crankshaft. You may or may not be able to hear the noise, which means that damage can occur to your engine without you knowing about it. Detonation is another name for pinging. Higher octane fuels and quality tuning is required to keep pinging under control.
