Questions about detonation and some other things...

[hysteria]

i've read some things concerning detonation and there is a lot of grey area between detonation and knocking in the threads i have read...

anyhow so the story goes like this... i was driving my car the yesterday, and i boosted it up to like 2 or 3 psi, and i heard a loud bang, which scared the hell out of me. i thought i toasted my engine or something, but of course it was just a charge pipe that had blown off. but i started wondering what detonation would sound like, because i have never heard it (and hopefully never will). see the grey area for me is with timing adjustment to get rid of knock and then an engine running so lean and hot that there is an explosion... that's the short version oh what i don't understand anyway. maybe my understanding is lacking in many ways but can anyone clear up the differences between preignition detonation/knock/whatever other detonation there is?has anyone witnessed detonation (fatal to the engine or not) first hand? what happens? what does it sound like? does the engine die instantly? will detonation most always kill an engine? has anyones engine survived detonation?

anyhow so i retightened the charge pipes all around and they haven't come off again since then (last night). i'm only using crappy clamps right now. i guess i need to invest in some t bolts...

thanks

[klattr1]

it depends on how extreme the detonation is. the sound can change with those extremes. some cars will just ping, some sound like hammers hitting pistons, some sound like marbles in a can.

my personal experience with detonation was with super lean afr's and lack of knowledge of proper base timing setting and my car made the "marbles in a can" sound and then i had 4 cracked ring lands after that.

[deezlins]

yeah it depends on a lot of things like how severe the detonation is and when it occurs as to how much damage it will do, but yes, it can destroy an engine.

pre-ignition is unwanted combustion before the spark event occurs and detonation is unwanted combustion after the spark event occurs. You want a controlled slower burn in the cylinder when normally running, but with preignition and detonation there is more of a spontaneous combustion usually caused from hot spots, too high compression or boost, not high enough octane fuel, etc.

[hysteria]

well thanks for the replies. although i guess i should hope there are no other replies to this because no one has experienced it (wishful thinking) i gotta ask, is there anyone else?

[lancefloyd]

not running a KA-T at the moment...instead just a stock KA-DE. However, I have the timing advanced a bit to improve what I can out of the engine, with intake and exhaust. I accidentally put 87 octane fuel in it just a while back, and I would get pinging under load. Remember all of our cars knock a little tiny bit...but thats what the knock sensor is designed to detect and adjust timing for. For those that have manual transmissions, and who want to know what knocking and pinging is and what it sounds like, you've likely heard it if you've ALMOST stalled your car at a drivethrough or something similar, and heard a diesel like clatter. This of course is not harmful to the motor beause its not under load.