pinging and detonation

[85Silveradoin04]

Are they both the same? What is your definition of each? How can you tell?

[ocbaud]

they are both the same

[TwinTurbo]

yes they are the same, it's a sudden peak in cylinder pressure (high heat) caused by a pre ignition and flame fronts colliding (this makes the burning process an explosive burn, faster than the speed of sound) when the piston is near TDC and therefire at a very unfavorable crank angle. the force can't be transferred into crank motion properly, isntead it's transferred into the piston and rod as a shock. The pinging sound is the explosive flame front travelling at a speed higher than that of sound hitting the cylinder wall, the piston, the chamber...whatever.

[85Silveradoin04]

Originally Posted by TwinTurbo

yes they are the same, it's a sudden peak in cylinder pressure (high heat) caused by a pre ignition and flame fronts colliding (this makes the burning process an explosive burn, faster than the speed of sound) when the piston is near TDC and therefire at a very unfavorable crank angle. the force can't be transferred into crank motion properly, isntead it's transferred into the piston and rod as a shock. The pinging sound is the explosive flame front travelling at a speed higher than that of sound hitting the cylinder wall, the piston, the chamber...whatever.

Thanks TwinTurbo, and what can cause this?

[TwinTurbo]

oil contamination in the chamber, too lean a mixture (causes hot spots), too high compression with poor quench height, burrs on chambers and pistons, carbon builduip on chambers and pistons, ... that's about what can cause it. It sounds like marbles in a tin can.

[85Silveradoin04]

Ahh, I see. Thanks for your time TwinTurbo.