This is taken off from some websitefor your info:
Pinging sounds like rocks being
thrown around inside your engine. It will never happen at idle, may
happen at part throttle, but is most likely to happen at full
throttle. It is usually accompanied by a small amount of smoke out
of the tailpipe, but don't rely on that.
Pinging is like... taking a cutting torch to your combustion
chamber. Your engine can stand anywhere from less than one second
to perhaps minute of pinging before it suffers permanent and
serious damage, depending on conditions.
The hotter your engine is, the more likely your engine is to ping.
The farther your timing is advanced, the more likely your engine is
to ping. The higher your compression ratio is, the more likely your
engine is to ping. The lower the octane of gas you use, the more
likely your engine is to ping.
So, in order to minimize the risk of pinging, do the
following:
Make sure your engine doesn't over heat!
Make sure your timing is not too far advanced.
Make sure your compression ratio is not too high (< 7.5 to
1)
If necessary, use higher octane gas.
If you take care of the first three, you shouldn't have to worry
about the last one.
hope it helps
