What does detonate mean?

[rvitek]

I've read and searched and all the threads that speak of detonating, don't describe what it is. What does it mean and how do I know if it's happening?

Thanks!

 

[Alec]

from howstuffworks.com:

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

the gas igniting before the spark plug fires. detonation as in knocking is actually pre-detonation; meaning it detonates early.

 

[rvitek]

Alright, thanks and I'm sorry Alec, but I guess I need to go down to basics. What is knock? And, while I'm at it, what's ping?

 

[expo5.0]

explode!

i have a question here too. my understanding is that in our engines the gas technically "burns" why then do we call early burning detonation? or is it that when it occurs early from compression that it does actually explode/detonate? which would wort of explain the use of the term detonation rather than pre-detonation, right? or no?

 

[Alec]

pre-detonation, spark knock, and pinging are all the same thing.

detonation is short for pre-detonation, knock is short for spark knock, and sway bar is short for anti-sway bar. we're just too lazy to say the whole term.

gasoline always detonates. pre-detonation is the bad thing, but most people just say detonation.

 

[diablo5969]

Originally posted by Alec
sway bar is short for anti-sway bar