RJ - you missed the key point - it is the "FREQUENCY of the oil changes" that determine the outcome. That FREQUENCY is way below the ability of the human ear to detect - it is kinda sub-sonic? But then again, I might be off my meds. ;)

Pre ignition causes engine ping, that rattle or marbles people hear when it happens. The sound of the pinging/rattle is caused by a very rapid expansion of fuel mixture in the cylinder that is not a controlled burn. Your hearing a shock wave that is going 770 mph inside a 3"(?) bore of the cylinder bouncing back and forth. Sorry if I might have misled you.

So you're saying that the sound is actually a sonic boom? Source please, I can't seem to find any reference.

Sound can't be a sonic boom because sound travels at a given speed (around 750mph). A sonic boom is created by a shock wave that exceeds that given sound speed.

Fwiw. This thread sure has drifted away from the original OP question. :dizzy:

Read abnormal combustion:
https://en.wikipedia.org/wiki/Engine_knocking
This was discussed and proven when I was taking the automotive technology course at SUNY Farmingdale, NY.

Cute Blue :roflol:

My Dad has a couple old Fats Domino records. I didn't know he recorded that one, though.

There WAS something useful in here after all...

:clappy:

Okay, just read it, but... no mention of speed of sound(or sonic boom). Maybe your rememberie is playing tricks on you.