what is engine knock

 

when you compress air, it heats. When you compress air fuel mixture, it reaches a point where enough heat/pressure causes it to self ignite. In an engine you dont want it to ignite at the wrong part of the cycle

 

Surly that is DET, i thought knock was piston shake at the piston travels up the bore.

 

there is so many diffrent things that can cause engine knock,fuel,engine were,ig ect.

 

Detonation is knock and is described well by Prana.

Piston shake rattle and roll up the bore is called Slap!.

Combustion is a controlled burn travelling around 30 meters a second.
Ideally you want the flame front to travel out evenly from the spark plug.
Knock is when that controlled combustion turns into an explosion.
Temperatures and pressures go through the roof and hence things start to melt, bend and break.


Andy