^^^^^^^

That..............

Pinking is when the ignition of the fuel doesn't occur at the right moment, you can hear it happening (hopefully), it sounds like a metallic ringing noise. You'll hear it especially whell when the car is pulling hard up hill.

It is serious, left unchecked it will destroy the pistons in a car.

hmmmmm

well it was only one set of plugs that where pinking the eqyem ones or however you say and spell it!!

the densos i took out and put back in recently werent pinking........ (when i last checked ill check this morning..

so what do i need to do then,,, eek

Are you sure you understand pinking correctly? You can't tell whether the engine is pinking by taking the plugs out and looking at them. You diagnose pinking by listening to the engine under load.

more than likely im mis understanding,

the, inside if you like of the plug is pink, you know where the spark comes from below the tip.......

lol..No. It's the name given to uncontrolled explosions inside the engine, not to the colour of plugs, or anything else.

With NGK the higher the number the 'cooler' running the plug. So if youre going to say thrash your car to the south of france it would help to put a cooler grade plug in. I think it is something to do with the thickness of the porcelain in the plug. So a B7 or B8 is a cooler running plug than a B6 but a B9 maybe a step too far .

I have tried all this in classic scooters over the years ,for example i find a 200cc vespa or lambretta benefits from going up a grade or two with motorway use or hard riding using B9ES, but found they bog down around town if you go too far with say a B10 plug.
So from that i've always gone up a grade in my 2cv's ,usually use B7HS as a rule as opposed to the standard 2cv grade B6HS.

With NGK the 'H' is the code for the length of the threaded part; so beware a B7'E'S is too long for a 2cv and would likely clout the piston, if you bought one by mistake and didn't notice.

I too found one of my 2cv's pinking with Eyquem and cured it by fitting NGK, perhaps my timing was on the edge or something but put the eyquem side to side with the NGK and while the thread is of course the same length the electrode protrudes further into the chamber. Perhaps they were designed when fuel was better and had lead in rather than all the crap they put in now.

Pinking is the nickname for pre igniting,ie the mixture is igniting too early usually due to timing too advanced, poor fuel ,etc and sounds like jingling keys in the distance when the engine is under load ,resulting eventually in pistons disintegrating or holing and damaged heads if not seen to.

So with the timing correct and the right plugs ,valve clearances set to Ken's recommended 0.2mm inlet 0.25 exhaust etc you should have no worries running ordinary unleaded . I always use higher octane (super unleaded-bp ultimate-shell optimax) in my scooters as being slightly tuned in some cases and ridden quite hard they pink on ordinary but i found recently my 2cv doesnt care wether i use either.

I will say though that as well as timing if you are paranoid that your car is running too hot go up to a cooler grade plug and use super unleaded , higher octane fuel = cooler running in a high compression engine so can't hurt in an everything helps way and i will certainly revert to using it on a long thrash in my 2cv van.

Sorry if i digress too much ,it's a slow day at work

i shall be buying some b7hs then i geuss

thanks for that, was very useful, learnt alot!!!

i will go and swap the plugs tomrow i geuss....

i was wrong, they werent br6hs i got they were bp6hs


are these ok ???

sorrry about confusuion could of sworn they were br....

That is NOT the right plug. The P in the number stands for Projected insulator. Basically the tip of the electrode pokes into the combustion chamber further than the B6HS plug.