Pre-ignition and Detonation

[bluerooster]

A decent explanation about the two, and various causes. While this guy is talking about alcohol, and nitromethane fed motorcycles, the principles still apply to just about all fuels and engines.

http://www.turbofast.com.au/racefuel10.html

 

[Capt. Geoffrey Thorpe]

Fwiw...

From "Internal Combustion Engine Fundamentals" John B. Heywood

 

[bluerooster]

It's upside down.