I'd appreciate it since I know what it is, but need to put it in sentence form.

Thanks!

 

<h1><blink>BOOM!</blink></h1>

 

sometimes known as:
<h1>KABLAM!</h1>

 

But more seriously, detonation is basically uncontrolled combustion. The classic detonation we would talk about here happens when either by hot spots in the chamber, poor fuel, or poor mixture distribution (etc, etc), after the initial spark event, as cylinder pressure rises, a second combustion event occurs (the uncontrolled combustion) and this second explosion collides with teh first explosion and the whole mess generates abnormally high and abnormally timed cylinder pressure, which gives you that nice rattle sound as it bounces off the heads/piston. Basically, instead of burning, the mixture spontaneously combusts, which is a faster more unstable burn.
You can also have this happen before the plug even fires.

 

thank ya

 

Speaking of which, I go nuts listening to and reading the automotive "experts" who use the word "explosion" to describe the combustion event.
On the call-in shows, I try to call immediately to ask, "If combustion is an explosion, then what's detonation?"

Funny, they never air the answer!

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Zslug

May the road rise to meet your treads...

'84Z, 5sp, stock 305, Edelbrock intake, GTA wheels

 

I guess I was too late on this one.

Detonation: see also tow trucks, rebuilt engines, group therapy, long walks to work, and Nitrous/Boost.

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14.62@96mph headers, muffler, chip, ghetto stuff, duct tape
89 GTA 305 TPI 5 speed 3.42 gears