sounds like a buzzy tinking noise from the front, Ken used to have a good link on u-tube

found it

i spent the other year trying to stop pinking on my car and guess what it was?




the door trim the metal springs had lost their tension and the ally strip on the passenger door buzzing with the revs sounded just like it

thats what i was after
thanks
sounds a bit like rice crispies being walked on, but you know when you cant quite put your finger on it, and you need showing...

it also sounds like synthasised rain!!

and if you get it wrong!

and the head

christ on a bicycle,
maybe i should take matt damper for a spin in my car, i take him to the pompey puddle ducks every month, and he didnt say anything about pinking last time on our journey back, there is a small sort of, crunchy sound about 25 but i think thats being in the wrong gear at the wrong time (seems to be in certain gear) and trying to accelrate to hard, so im probably panicking now so ill shup

This one too

that must of been a few psi down on compression viking

Pinking sounds like glass tinkling...tink tink tink

I have a confession, I still don't understand all this pinking stuff. Basically it's when the mixture is igniting earlier than it should, right?

Ok, so one cause can be that the ignition timing is too far advanced, obvious, straightforward, makes perfect sense. Retard the timing, problem cured.

Another cause is fuel with too low an octane rating, am I right? Now the octane rating is a fuel's resistance to compression ignition, so the problem is being caused by the fuel igniting as a result of being compressed, before the plug fires. And yet people recommend retarding the ignition timing as a cure.

Another cause is too high a compression ratio, now it makes sense to me that a high compression engine will need a higher octane fuel, but then I read things like this; Surely it's not just me that sees a breakdown in logic there?

And as Ken said on the previous page, pinking occurs on full throttle because when the throttle is partially closed less mixture enters the cylinders, and therefore pressures are lower. Which again suggests to me that compression ignition is the cause. But I can't see how the three things he suggests could have the same effect.

Retarding the ignition: suggests the plug is simply sparking too early.
Re-jetting: perhaps a lean mixture is more prone to compression ignition?
Using a cooler plug: suggests that an overheating plug is triggering ignition without sparking.

I did read somewhere that pinking, detonation, and knocking are not the same things, is what's happening here that all these problems are being lumped together as pinking, and the different solutions are actually curing different things?

This just isn't logical in my head. What am I missing? I'm not saying what anyone else has written isn't true, just that I don't understand it.
I don't understand, I don't understand, I don't understand.

Joolz,
perhaps the first thing you may need to clarify in your mind is the basic difference between a 'spark ignition' engine and one which is 'compression ignition' ?

The second thing would be to realise that the internet is flooded with advice, some of it 'informed' and some of it 'not quite so well informed'.

In the case of this particular quote, which seems to be causing you considerable confusion, it seems to me that the clown who drafted it hadn't got any idea what he was talking about.
Either that, or he was talking out of the wrong end of his body...

ken

Pinking or knock occurs when the ignited charge rather than burning evenly releasing the energy in a controlled manner, it goes off and self combusts like you try to chieve in a diesel!

As can be seen from the pictures there is localised heat dammage opposite the spark plug, (Vikings piston is upside down from its fitted position)

The plug fires and the flame front moves accross the chamber the pressure in the chamber rises and if conditions arent right the unburnt charge at the other side spontaneously combusts in an explosive way, it occurs at one of the squish points in our engines.

It causes excess heat and it breaks down the barrier layer of gas that stops the burning petrol from melting the aluminium.

it cuses a shock to the engine which is what we hear.

the common problem seen on our engines is that the local heating and the aircooled engine means the oil film breaks down and so the piston is dammaged as can be seen by the smear of alloy on the piston skirt, as well as the shock having distorted the land between the compression rings, this nips the rings and compression is lost....often referred to as "partial seizure"

good petrol should burn in a controlled and even manner, modern petrols have many additives to achieve this as well as others that are there to make it "cleaner and greener and its these that seem to be causing the older M28 engine problems as it burns hotter and faster to suit the modern engine

Sean