I know what it is and i know its caused by the car's timing being to high, but what exactly is it making the noise and how much damage does it actually do to your engine?

(i'm not suffering any problems relating to this i'm just interested)

Damage, mmm pistons broken, valves bent, crank stuffed

Im not an expert on this but pinging (pre detonation) occurs when fuel is ignited too early when the piston is on the up stroke. When the piston is pushing up and the ignition of fuel and air (explosion) is forcing the piston back down prematurely something has to give.

Usually your pistons and piston rings are the first to take the hit and fail, followed by your conrods, crank and valves. Its a horrifically nasty thing for your engine to go through. You will notice it on alot of poorly tuned import turbo's and the result is clear, new engine shortly.

Also, pinging is more dangerous in a forced induction engine than a N/A engine and things will break much more quickly where there's a turbo involved, simply because the extra air means a bigger explosion.

Pinging is caused buy high temperatures, it can also be induced by advancing the timing. High temperatures in the combustion chamber is mainly caused by a high air fuel ratio. Peak power is around 16:1 on a petrol motor so manufacturers try get as high as they can without raising the temperature too high. 14:1 is normal for a natualy aspirated motor, the extra fuel compared to 16:1 air/fuel is used to cool the combustion, that is it. idealy the motor would run at 16:1 all the time for fuel efficiency but this causes the combstion to reach temperatures of 1600 degrees which is enough to melt the tops of pistons and even warp cast iron blocks. Pinging happens at these temperatures because the head or piston is hot enough that once the air/fuel mixutre is sucked in its heated and then once compressed will self combust earlier than when is desired (when the spark plug is ment to fire) this can be heard as a pinging noise. This leaning out pinging is more dangerous to a motor because piston and block damage can be terminal to a engine.

Pinging due to timing is also dangerous because as the piston is trying to compress and the crankshaft is working to push up the piston, the force of a internal combustion is acting down upon it. it only happens very late in the compression stroke but is still early enough for the motor to lose power and put a incredibly high force onto the main bearings and the crankshaft itself. pinging due to timing can also damage the motor because its adding stress to the big end and main bearings aswell as wearing out the compression rings.

The only thing I'd disagree with there is where you say 16:1 is normal for N/A and 14:1 is used to cool combustion...

14.7:1 is used because it's the ratio at which the cat converter is most efficient and emissions are lowest.

16:1 is only used on very light load cruising.

N/A engines usually run around 12.5:1 at max load, turbo engines at low 11:1 ratios, I believe, and there the extra fuel is for cooling.

any extra fuel past 16:1 is used for cooling. peak power and emissions is with the least amount of fuel possible without starving. 100% conversion rate is at around 16:1

I have a V6 TS, a while back when I filled up with those discount petrol servo's, i.e, woolworths, and alot of the small independant stores, about a day later my motor would ping something shocking!! My mechanic said (im not sure if he's correct) it was because fuel has a shelf life of 2 weeks, and alot of the small chains import there fuel, therefore the fuel is basicly off by the time it goes into our tanks??? Then the fuel does'nt have a high enough octane to fire the car!! He told me to use Optimax or Ultimate Premium fuels, when I changed to Premium, the ping stopped!! But if im outa fuel and miles from no where, i will fill with a small outlet servo, then it starts pinging again!! I always use premium now!!
Is this the same kinda engine ping?? Cheers all

I can understand getting some pinging with a really crap batch of fuel, but you shouldn't be getting pre-detonation every time you use regular unleaded :doubt:

Incidentally, higher octane fuel is harder to ignite than lower octane, which is why it resists detonating until the spark plug fires, so saying that "the fuel does'nt have a high enough octane to fire the car!!" is putting things the wrong way around :)

fairly unlucky is all i can say, you've got bad fuel more than once.