Can someone please teach me what detonation is?
I just got a car equipped with the mods in my sig. I want to know
what is it?
when does it occur?
what harm can it cause?
what is done to prevent it?
One cause of detonation is advancing the timing too much, or running too few of octane rating in your gasoline. Either retard your timing or run higher octane gasoline.
Detonation occurs when part of the a/f mixture ignites on its own then the spark plug ignites the rest of the mixture then the two flame paths collide causing a violent ping. You also have pre-ignition; That’s when you have a “hot” spot in the combustion chamber ( like a sharp part of the piston) that heats up and causes the a/f mixture to ignite. Giving the same result as detonation.
Detonation occurs when part of the a/f mixture ignites on its own then the spark plug ignites the rest of the mixture then the two flame paths collide causing a violent ping. You also have pre-ignition; That’s when you have a “hot” spot in the combustion chamber ( like a sharp part of the piston) that heats up and causes the a/f mixture to ignite. Giving the same result as detonation.
sounds good. it's a snowball thing too, as the detonation or pre ignition cause temps to skyrocket, and this causes more preignition or detonation. other causes of preignition are carbon deposits in the chambers. carbon deposits can also raise compression ratios, exasperating problems.
just listen for pinging and if you hear some, try either backing timing out or higher octane fuel, whichever is most pratical (usually timing). i back timing off a degree or two in the summer (110* here) to help ward it off.
you are right to ask the question, as detonation/preignition of any kind is horrible and extremely stressful on your motor.
David, i have wondered this, and you touched upon it: i kinda thought that the pinging noise was caused by the piston being slapped around in the chamber (frequencies of violent shockwaves from the two explosions, squish area flaming, etc). am i just wrong, partially wrong, or is it really from the two flame fronts colliding? (not trying to be a jerk, just want to learn). thanks.