Diesel Knock

Hello,

I saw in the diesel knock lesson the graph that showed cylinder pressure and the diesel knock burn spike that had almost zero real effect on the pressure in the cylinder. Is It such a small amount of fuel being burned creating the knock in such a short time that it has no effect? Can someone explain this phenomenon in a little greater detail?

Thanks!

The knock is generated by the fuel air mix combusting very rapidly after the ignition delay period, however in relative terms this is a small amount of fuel and fuel will continue to be injected and burned through the combustion cycle so the net effect on peak cylinder pressure is minor.