Blog — compression ratio and boost

Courtesy of TurbobyGarrett.com ( http://turbobygarrett.com/turbobygarrett/compression_ratio_with_boost ) Before discussing compression ratio and boost, it is important to understand engine knock, also known as detonation. Knock is a dangerous condition caused by uncontrolled combustion of the air/fuel mixture. This abnormal combustion causes rapid spikes in cylinder pressure which can result in engine damage. Three primary factors that influence engine knock are: Knock resistance characteristics (knock limit) of the engine: Since every engine is vastly different when it comes to knock resistance, there is no single answer to "how much." Design features such as combustion chamber geometry, spark plug location, bore size and...