Spark plug condition.

[Simmo68]

Hello VF'ers, L77, tuned ,OTR and exhaust/headers.
Fitted new intake gaskets a couple of years ago, then had it tuned as above, this was tuned with the original iridium plugs.
Since the tune I fitted NGK tr6.
I found that it had a vacuum leak due to not cleaning out the thread holes. I realised this issue recently and cleaned out the bolt holes, it's sealing properly now and running much better. I recently found after a high rpm run that it was breaking down which made me take a look at the spark plugs. The picture attached is the condition of them, I fitted new plugs and she runs nice.
My question is, what do you guys think about the burn, rich/lean or wrong temp range, or is it better to take a look at the new plugs to determine the burn?
Have an awesome weekend

 

[07GTS]

seems a bit rich but that only works for the last event the cylinder was doing so idling, id check the 02's to see if they are also rich looking as they may not be operating properly (depends what tuner done also) for around town and idling in closed loop they should stay clean bit lighter then yours and no buildup, maby drive around for a week with the new plugs then check one on each side again to see if they are better or same

 

[Simmo68]

seems a bit rich but that only works for the last event the cylinder was doing so idling, id check the 02's to see if they are also rich looking as they may not be operating properly (depends what tuner done also) for around town and idling in closed loop they should stay clean bit lighter then yours and no buildup, maby drive around for a week with the new plugs then check one on each side again to see if they are better or same

Thanks for your advice 07 GTS, I'll do just that. I mean I'm not complaining actually, the car runs awesome and more easy power than ever before but it just seemed to be the best thing to ask someone that knows better.
Cheers

 

[losh1971]

Also check your intake for oil residue.

 

[Simmo68]

Also check your intake for oil residue.

There does seem to be a light film of oil usually, is that due to a poor pcv system?

 

[losh1971]

There does seem to be a light film of oil usually, is that due to a poor pcv system?

Yeah and there is a fairly easy fix. I'm not the best person to advise on it though as I haven't touched mine because it doesn't oil up. @07GTS or @Fu Manchu can probably post a link to the thread.

 

[shane_3800]

you don't get a vacuum leak via the spark plug holes.

That build up is oil not fuel.

Go back to an iridium plug in a hotter range and she will run fine.

People that say to go back to the thick electrode are just parrots, they see it work for top engine builders but don't understand why, you only go the thick electrode plugs if you need to, like as in higher power.

 

[07GTS]

you don't get a vacuum leak via the spark plug holes.

That build up is oil not fuel.

Go back to an iridium plug in a hotter range and she will run fine.

People that say to go back to the thick electrode are just parrots, they see it work for top engine builders but don't understand why, you only go the thick electrode plugs if you need to, like as in higher power.

or just use the TR6 as is and fix the oil problem then the engine will be better all round, any oil in the chamber is killing octane and none should be there anyway just the factory efforts are minimal to stop it

 

[ephect]

It does look very burnt around the ceramic tip, also the earth lug looks pitted. Is the gap correct?

 

[Simmo68]

It does look very burnt around the ceramic tip, also the earth lug looks pitted. Is the gap correct?

I gapped them at .080mm as per workshop recommendations, the new set are out of the box @ 1mm.
I will monitor the condition as time goes on, I'm putting a catch can on tomorrow also.