Check out these TR6 plugs if you wish... 7k~ miles 5.3L

[kingtal0n]

Hello fellow performance enthusiasts,

Just hoping for insight. I usually get 15k-20k from a set of 'copper cheap plugs' but these I feel like I am only getting 7k ish. I am re-running the experiment and will confirm actual lifespan (6mo-1yr I guess) but for now, here are plugs I removed.

They gave me a hard misfire at idle and a slight misfire at WOT. No issue driving normally/cruise not even a hiccup.

In their defense they are the first plugs I used in my swap, they went through first run, testing, several configurations, etc...
However new plugs are already showing slight signs of misfire at idle (its only been 1000miles~)

I think something I am doing is 'eating' them. Maybe the higher average cylinder pressure of the V8? (I am used to 4-cylinder and 6-cylinder configs). Any ideas?
My thoughts are possible:
1. dwell is wrong (can this over charge coil / eat plugs? I have no idea)
2. plug wires are poor (some stock replacement wires 7k ago)
3. coils are 'weak' (15 year old plug coil packs?)
4. engine getting too hot (This I could remedy by venting/ducting which will happen but not just yet)
5. ??? halp

image.jpg


Whats causing those dark spots too? Its like the spark is avoiding the electrode or something. I used 87 octane for a while too with these btw. The silver stuff is anti seize lol. its gets on everything.

Im going to try some iridiums in a colder step or two soon. Just curious how far coppers will get me. I've had this sort of thing happen before in 2jz-gte where iridiums fixed the spark misfires at WOT, but I've never had an issue at IDLE. Thats just weird. Idle misfire? I mean, the cylinder is like half full at idle right? I think its just getting hot, hot plugwire/hot plug in a cramped installation. Nevertheless... any halp XD
to me these plugs look fine, i would continue to run them. but they don't work anymore so something ain't right.

[85K5Jake]

Is that burnt oil on the threads? If you have bad valve seals you could be leaking oil into the cylinders and coating the electrodes causing your misfires

[MMGT1]

Looks like the anti seize was applied to the entire thread of the plug, that will cause bad things to happen. If you use anti seize only apply to the top 4 or so threads. You need good contact in the lower threads as the anti seize will "insulate" the plug from the head.*Major requirement so the head can absorb the heat of the plug firing in there. Heat range does look good on the plug as it seems like its showing heat a good 5 threads up from the bottom. The "rounding" of the electrode does tell me they are done. Install a new set, anti seize only on the top few threads, and install. If you have a track nearby it is the only way to use plugs to tune the engine. You need to take a new set with you to the track, install there, pull up to start, run a pass, and pull the plugs. Then they can be properly inspected and used to see whats really going on. If at all possible, even shutting down at the end of the run, push it to the hangout area, then pull them. You will need a second set of plugs with you so you can bring your test ones home, cut the threads off of a couple and inspect where the porcelain meets the threads of the plug. Up inside there is another area that needs to be seen to use plugs as a tuning tool. If you go this route, PM me and Ill have a look at the plugs with you and give my 2 cnts on what I see.

[kingtal0n]

Looks like the anti seize was applied to the entire thread of the plug, that will cause bad things to happen. If you use anti seize only apply to the top 4 or so threads. You need good contact in the lower threads as the anti seize will "insulate" the plug from the head.*Major requirement so the head can absorb the heat of the plug firing in there. Heat range does look good on the plug as it seems like its showing heat a good 5 threads up from the bottom. The "rounding" of the electrode does tell me they are done. Install a new set, anti seize only on the top few threads, and install. If you have a track nearby it is the only way to use plugs to tune the engine. You need to take a new set with you to the track, install there, pull up to start, run a pass, and pull the plugs. Then they can be properly inspected and used to see whats really going on. If at all possible, even shutting down at the end of the run, push it to the hangout area, then pull them. You will need a second set of plugs with you so you can bring your test ones home, cut the threads off of a couple and inspect where the porcelain meets the threads of the plug. Up inside there is another area that needs to be seen to use plugs as a tuning tool. If you go this route, PM me and Ill have a look at the plugs with you and give my 2 cnts on what I see.

Hey thanks. So you can tell they are 'done' for sure? I sure can't! "rounding of electrode" Hmm I going to have to learn this. Any further details?

The anti seize snakes its way down from the top threads over time I guess. Plus when i take the plugs out it kind of gets all over them on the way out. I hear what you are saying though. I probably used too much on them the first time also.

So what do you think 'killed' them though? "rounded the electrode"-? Too many runs? Miles? Too much heat? Spark? How do you "finish" a set of plugs

[MMGT1]

I would guess they held too much heat. Look at a new plug and the cut of the electrode is very sharp, blunt. As a plug wears the electrode will lose some material and begin to "round off". That doesn't happen with only 7k on them unless they are holding too much heat. Using a copper plug, that you would change every 20k anyway, I would never use anti seize on them. Not necessary as they will never sit in the head long enough to seize. The "long interval change" plugs sure, no to the copper. You want to see a heat mark on the threads that go a good 5-6 threads up the plug which in that photo looks like it does. So I think your heat is ok, but a proper test of a set will tell much better. You have to let a plug transfer its heat to the head, its how it works. Too much of that stuff will insulate the plug, over heat it, and cause them to go down like those seem to have in a very short period of time.

[kingtal0n]

I def feel that heat is playing a role. Good notes and I am glad I didnt put any anti seize on the new plugs at all. seeing how I had some in there alrdy and plan to take them out in the near future.

Will keep a look out

Oh and does anybody happen to have the part# for NGK iridium replacements for the TR6, i would go 7 or 8 heat range though. probably 8 until I have water injection installed. I found some plug numbers and emailed NGK but no response.

[MMGT1]

The plug is still a TR6 still I believe. It'll be packaged as a TR6 IX. The TR6 is one heat range colder and should work fine in a boosted application. But how much boost are we talking here? If your getting Meth injection involved then you should be able to definitely run the TR6's in it, again though, how much boot are you making this thing eat...lol

Here is a link for the TR7's if thats what your looking for. Summit has them:
https://www.summitracing.com/int/par...3690/overview/

[kingtal0n]

Hey thanks again! I spent like an hour looking for an iridium mate and came up with some of the weirdest PN# lol


Well for starters the plugs you see in the picture were run almost N/A, up to about 3psi of boost. And they look pretty "HOT", if not ideal already. So I am thinking TR7 for 4-12psi of boost and TR8 for 12-18psi of boost. with no water.

Back to 7's with the water injection probably. if I use meth it will be the blue windshield washer fluid stuff from somewhere. Before I do any of that though I need a couple more things so for right now I am just seeing how cold of a plug I can get away with and still keep my economy/and no fouling.

[MMGT1]

Those will come gapped at .038" as well. Be SUPER CAREFUL and reduce that to .030", even .028" for higher boost. The super thin electrode will be easily damaged if you even slightly hit it, caution, caution, caution. I agree with your line of thinking on heat range to boost levels, but the threads of the plug will tell you if your using the proper range. Just remember to look for heat line to go 5 threads up the plug it'll be in the right range. They will foul super fast if they are not showing enough heat transfer to the head.

Edit: For the last three years Ive been dealing with almost entirely builds with boost and a lot of Meth injection. You'll be surprised how little Meth is needed to run the system properly, and its cheap. I know washer fluid will do in a pinch, but use meth, 50/50 and you wont be disappointed. If you haven't bought a meth kit yet, be sure to check out Snow. AEM is a good name too, I know, but I think Snow has got it together where it counts. Amazing systems for the money they ask.

[kingtal0n]

I thought a colder plug was colder because it transferred more heat out of the CC. Meaning, into the head/water. So I am bit a confused by you saying that a colder plug will transfer less heat, where is it going then? Into the center electrode that leads out of the plug and into the plug wire maybe? Just something I really don't get yet that I never paid too much attention to

[MMGT1]

The insulator nose of a colder spark plug is smaller, hense it doesn't heat up as much as a hotter plug with a larger nose. The pathway for heat to get out is shorter in a colder plug, yes, so I get what your saying. I should have worded, "creates less heat at the tip". There still should be a heat marking around 4 or 5 threads up the plug. If its not, then the plug is too cold. If the pathway is too short the plug will not get hot enough to not foul.

There was a great write up I read years ago and just tried fruitlessly to find it on the web. This is a good one though. Wish I could find the one I was looking for though as it was much more detailed than this one. Anyway, have a read...
http://www.dragstuff.com/techarticle...ark-plugs.html

If I find the one I'd like to show you Ill post a link to it.

[kingtal0n]

Cool thanks, and it just occurred to me to ask, should I be indexing these? And if so, which direction

[MMGT1]

Indexing is a total waste of time. People used to think indexing worked, it does next to nothing and is seriously not worth putting any effort into. There has been a debate going on over that for years, but I don't believe in it myself at all. I did find another article in my search here that has a good pic of what the plug should look like when you cut the threads of of them. You need to be able to really see where the porcelain meets the metal jacket. Tip of the porcelain will give you idle information, middle mid range, and way up where it meets the jacket will tell you if your WOT AFR is in the correct range for the engine.

http://www.hotrod.com/articles/spark...eave-hp-table/