Reading spark plugs

[lolsteve]

So trying to work out if I've got pre ignition action going on. Tried comparing with pictures but can't hurt for a second opinion

[cully]

get a knock box and listen for it

[lolsteve]

Wanting to make up some det cans but just wondering if I can get an indication from the spark plugs.
to me they don't look damaged or anything which is what some of the predet pictures show

[Piggy]

looks pretty good that

[lolsteve]

Don't suppose anyone would make me up a set of these?
http://www.d-series.org/forums/diy-forum...t-can.html

[Niall]

They look pretty healthy to me mate.

[Rippthrough]

Looks like they've had some antifreeze contamination at some point tbfh. Can you get a better picture of the ceramic?

[lolsteve]

Considering it's a k series that would surprise me

[lolsteve]

Just took out the new ones to see how they fair after the track 

[Rippthrough]

That's more like it!

[lolsteve]

So the new set look right? They're the ones that were on the dyno and track so imagine they would have gotten the most abuse

[Rippthrough]

They look pretty much perfect to be honest

[lolsteve]

Awesome, is there anything else to look out on the spark plug? Or other things to for with too much advance?

[mcglynn]

Plug looks white to me? AKA lean as fook

[Poodle]

Just took out the new ones to see how they fair after the track 

The white bits are meant to be that colour when new.

[lolsteve]

Yea okay but it's the brown bits and the black around the ring etc

[silverzx]

That looks like an epic gap on those...

[Poodle]

Yea okay but it's the brown bits and the black around the ring etc

That was a response to McGlynn lol. Could do with a picture that's actually focused on the electrodes, can't really tell where it's blurry, but they look alright to me.

[mcglynn]

I know the ceramic is white, im referring to the tip/electrode.

White = lean/hot.
Brown = good a/f & warm
Black = rich and cold

Looks white to me but as said its not a great picture.

[r3k1355]

This pic looks lean, the ceramic is bright white and the metal tip is whiteish.



This pic looks fine, the ceramic is slightly discoloured and the tip is dark.



If it's the same engine, nothings been changed, re-mapped or anything then it's probably just a trick of the light or something.

[lolsteve]

That looks like an epic gap on those...

Wondering if that's why I got a misfire P0302 ELM code the other day and the lumpy idle 
Didn't check the gaps on them before putting them in, might get a feeling gauge just to be sure as the new ones might be the same

Same engine, except the darker plugs had been in the car when I bought it and the whiter ones I had just put in. 
Put car back onto standard map now so will see how they look later

[Rippthrough]

I'd expect the tips to be whiter and the ceramic cleaner given it's been run hard so the plugs will have been hotter. There's still the tan deposits on the ceramic, dry carbon on the lands, and no apparent pitting on the electrode so I'd still say they're spot on.

[lolsteve]

Awesome, now to just fix the misfire issue. Ordered a spark plug gap tool and been reading of people getting misfires when set to the 1mm recommended size. So will be trying 0.7mm see if that helps fix it

[welshpug]

most plugs these days should not be adjusted, if there's issues with the standard plugs as they are I'd be looking elsewhere.

you risk breaking the earth off if you bend them.

[lolsteve]

The new ones I bought were original rover ones so don't know if that makes a difference to them being gapped or what. Would it make a difference if they were at different gaps considering this uses a wasted spark method? I.e if its putting through a voltage to make the easiest of the two spark then the wider gapped one would struggle more?

Also reading up alot of people complaining of misfires at 1mm along with a gentleman who claims he was involved with the testing back in the day and that putting it to about 0.7mm made no effect on the emissions/power yet reduced the demand on the ignition system.

[welshpug]

doesn't make any difference whether its wasted spark, dizzy or sequential, if it needs 0.7mm gaps then rover would have specified plugs with 0.7mm gaps.

if they're genuine plugs then the gap should be correct without adjustment, same goes for any direct replacement NGK, Bosch etc.