3gEclipseTurbo

iTrader: (12)

I just hit 5xxmiles on my built motor so i pulled it in to do a oil change, and checked the plugs and there Black! There 100% done. Can this cause knock? Or would it cause blow out which could then be picked up as knock?

iTune

iTrader: (3)

Post pics of the plugs in question......

A lot of weird things happen with plugs are less than optimal. I will need to see the plugs first, to comment further.

3gEclipseTurbo

iTrader: (12)

The whole end of the plug that is in the camber is Black, like pure BLACK.

iTune

iTrader: (3)

Is it wet fouled or dry fouled? Gap may have opened up which was causing misfires and fouling, unless the plug is wet fouled. By wet, i mean oil.

How old are the plugs? Check the gap on the plugs in their current state, report back. I ask about wet fouling, because if there is oil present in the combustion chamber, this is a problem and will cause knock, because oil present in the combustion process lowers the detonation threshold. Also, if there is oil, you'll need to find the cause ASAP.

If it's dry fouling, again look at gap. If these plugs are old and have a lot of miles on them, there will be electrode and ground strap wear, which will cause the gap to open. Also, if these are copper electrode plugs, the electrode itself looses it's sharp edges, which will not help faclilitate the spark jump from electrode to ground strap.

Also, if these plugs were improperly torqued, this will impede the heatsink to the head(the spark plugs second job) and thus cylinder temps and pressures will be raised, which will cause knock.

3gEclipseTurbo

iTrader: (12)

there copper ngk 8es. Car doesnt smoke and there all the same so im gonna say its dry fouling. they only have 5xx miles on them, i went copper to break in the motor, i have 8eix on the way. The car was running very rich for a while, while i was tuning. afr were below 10 in boost for a good 15 pulls an was idlin kinda rich on warmup 13's.

3gEclipseTurbo

iTrader: (12)

The reason Im asking this is i turned up the boost and while i was tuning it seemed to "knock" even when i pulled timing and started sputtering on the last two pulls before i pulled the plugs. Im hoping his is the cause.

iTune

iTrader: (3)

Why break in the motor with copper plugs? There is no need for that, but regardless, you're running too rich, which can cause knock on it's own. Carbon will build up and cause pre-ignition as it ignites before the ignition event. Running really rich will then also foul your plugs and make things worse. Change the plugs over to NGK iridium ix plugs and properly gap them.

iTune

iTrader: (3)

What gap are you running? Too small can cause elevated firing end temps, which will cause knock(pre-ignition) as well....plus, if gap is too small, there will not be enough spark exposed to the mixture, which will cause fouling at high boost, and rich AFRs. You want to run the highest gap possible without mis-fires and re-tune AFRs into the mid 11.5:1 range at peak VE, tapering to 11.1:1 after 6000 rpm.

iTune

iTrader: (3)

one last thing, if you're in a pinch, you can clean the plugs with fuel and a wire brush, then re-gap them (starting at .028 or so, working your way down until you have no misfires). This should get you by until the NGK Iridium IX BR8EIX plugs come in.

03whitegsr

iTrader: (8)

Yes, misfires can be detected as "knock."

The color of the plug only indicates the running conditions of the last 30 seconds or so. If the car runs lean under boost but rich at idle, and you shut the car off after idling for a short time the plug will show rich combustion conditions. You will not see any sign of the lean condition in the color of the insulator or fire ring. WOT will then tend to burn off that carbon and hide the rich condition if you shut down during the lean conditions.

Excess cylinder heat will show up on the ground strap in the heat mark. Detonation will show up as specs of carbon (oil passing the rings due to detonation) or aluminum (part of your piston/combustion chamber). You can look at the color of the fire ring to tell AFR when it was shut down and a few ignition events before, but why when widebands are so cheap?

You can easily gap copper plugs down to 0.020" on an inductive ignition and not have any drivability issues. I prefer to run a colder plug that is gapped tight as it runs well for drivability and then performs much better under boost.

iTune

iTrader: (3)

Misfires can be detected as knock, depending on what's causing the misfire. It's more about the cause of the misfire than the misfire itself.

You're correct about reading plugs. But, this is not what we're discussing currently and is not relevant to this discussion. His plugs fouled at some point, the point at which they fouled, they were unable to heat up to "self-cleaning" mode. Finding the cause of this initial fouling(and where it happend) is what needs to be done and is what we're discussing.

charlie.tunah

iTrader: (7)

good info guys

3gEclipseTurbo

iTrader: (12)

I have the afr good now but its just too late for these plugs lol. 13.0-12.5 on onset of boost, 12 at peak boost and 11.9-11.5 to readline, as I have been told by a few tunes not to go richer than 11.5. But ya i can feel the car missing/spark blow out from the plugs being fouled so I just have to wait for the NGK Iridium IX BR8EIX plugs to get here. The reason I used the copper plugs is I have seen and read that most of the time you have to change the plugs with the oil change at 500miles, and being the Iridiums are $40 a set, and copper are only $10 a set a got copper. With the intension of switching to Iridium.

3gEclipseTurbo

iTrader: (12)

I have a wideband.

iTune

iTrader: (3)

Again, what gap are you running? You're tuning a little too lean. While this is good for MBT, it's bad because it leaves little room for error. I would tune just a tad richer....11.5:1 at peak VE, tapering down to 11.1:1 after 6000rpm. You will only give up a few ponies, but will gain a lot of room for error, which IMHO, is much more important. Leave a little power on the table.

I see your point now, regarding the copper plugs during break-in. The crapper plugs are much cheaper, if you're just going to throw them away after break-in. I've just been battling the notion that copper is better than iridium for some time on this forum, so i thought you were of the same retarded mentality....i now see you're not(thank God for you). Iridium plugs will always be better than any copper plug, for several BIG reasons.