highperboi
Senior Member
what makes knocking and pinging noises ???
knocking/pinging??
- Thread starter highperboi
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highperboi
Senior Member
yeah i know that but what makes the noise??? how does using lower octane make noise???
dohcvtec_accord
WRX Sellout
The air/fuel mixture gets ignited before the piston reaches top dead center.
highperboi,
It sounds like you want a more technical explantion.
Hot spots will allow the air/fuel mixture to pre-ignite. As the piston is being forced upward by the connecting rod, the pre-ignited explosion will try to force the piston downward. If the piston can't go up (due to premature explosion) and it can't go down (because of the upward mo-tion of the connecting rod), the piston will rattle from side to side. This is why timing is soooo important. The resulting shock wave causes an audible pinging sound. This is detonation. Enough pre-ignition generally results in detonation. These shocks waves are what cause ring lands to break etc...
Hope this helps.
It sounds like you want a more technical explantion.
Hot spots will allow the air/fuel mixture to pre-ignite. As the piston is being forced upward by the connecting rod, the pre-ignited explosion will try to force the piston downward. If the piston can't go up (due to premature explosion) and it can't go down (because of the upward mo-tion of the connecting rod), the piston will rattle from side to side. This is why timing is soooo important. The resulting shock wave causes an audible pinging sound. This is detonation. Enough pre-ignition generally results in detonation. These shocks waves are what cause ring lands to break etc...
Hope this helps.
riverfenix
Junior Member
i am getting the same tapping sound, i was wondering if that could be it, i have the apex s-afc and i was wondering if it is better to go alil leaner to stop the problem?
highperboi
Senior Member
kool i learned something new thanks
riverfenix,
If you even suspect your pinging or detonating, DO NOT! lean out your motor. Tapping could be a million things.
Such as valve tap. Meaning your have too much play between cam and rocker arm. You should also get it on a dyno and watch the O2 reading. You might want to make you curve more rich if indeed it is pre-ignition.
If you even suspect your pinging or detonating, DO NOT! lean out your motor. Tapping could be a million things.
Such as valve tap. Meaning your have too much play between cam and rocker arm. You should also get it on a dyno and watch the O2 reading. You might want to make you curve more rich if indeed it is pre-ignition.