I have TR6 plugs - monitored with Autotap the first few times on the 100 shot (starting shot) and the first few times on the 150 shot. Everything looked fine. I pulled half the plugs so far because it was making a noise - I blew up the #1 plug.

My questions:

1. What happened? Can running too rich cause this (had air in the line one run - bogged for a bit)?

2. What do I do about the #1 cyl now? Just put a new plug in and hope for the best, or are the pieces still in there?

3. How do the rest of my plugs look? I think good.

TIA

 

Looks very lean to me!!

 

Compare your plugs to the ones in this link and that will help you diagnose your problem. Also peruse the site because there are some good articles that may help you out!
http://www.dragstuff.com/techarticle...ead-plugs.html

The link below is to a spark plug forum where they can help you diagnose and solve your problem much better than most can here. There should be plenty of spark plug genious' on that site. You may just want to sign up and become a member if your going to stick with nitrous!!
http://www.dragstuff.com/phpBB2/viewtopic.php?t=22


I hope this information helps and let us know how it goes!!

 

I disagree..........but you can't tell unless you look at the base of the porcelin under the metal. I would say #1 is definately detonating due to the melted plug! Don't know for sure.............I recommend checking the attached link and asking some of the guys from that forum.

 

In the pic it doesn’t look like it melted (lean), it looks more like something hit it or it was possibility a factory defect. It's a bit of a weird one for sure.

Matt

 

Time to borrow a bore scope and see what it looks like in that hole. I have seen a few TR6s come apart. Some toasted the engine and some did not. One of the reasons I switched to Autolite plugs.

Take a look at the cylinder and do a compression and leak down test. if it pass's put in a new set of plugs and ADD FUEL! Rich is ok

 

what are you doing for timing and fuel do you still have the stock pump ? i see you have a cam if your timing is advanced thats going to be a problem

 

I still have the stock pump for now, but have a fuel pressure gauge, and it has never dropped below 58psi. As for timing, I have a resistor wired in with the IAT sensor. I did notice once on the 150 shot logging that the timing reached 28.

 

As for #1, I would say during install you dropped it, or when gapping it you stressed it too much/manufacturer defect. I say that due to the breakage of the porcelain, more than anything.

Disagree on the lean comment? No. Your engine is going lean somewhere, either down low in rpm or top end. The porcelains are bleached white terribly so. Yes, the right plug has a slight tan right at the top of the porcelain, which is how they should look all the way around, but they dont! If the plugs where pulled right after a run, before washing off the plug by driving back to the pits, then your lean up top for sure.

You also have too much timing. Look at the mark right near the base of the grounding strap...its too low, you want it mid arch slightly fore or aft depending on shot size etc.

Detonation is visible as well. Look at the base ring of the plug (area at the working end of the threads...the facing) its speckled with tell tale signs of detonation. As well as base of the grounding strap. Lastly look at the few speckles on the far right plugs porcelain....tan is good, spotted is not.

Now, there seems to be a rich condition, and with your setup, I am betting it is at idle. There is chuky carbon buildup on the face of the plugs, yet the porcelain is chalky white, so rich (carbon sooted) at idle, then is blown off on the lean top end (speckles).

You'll have an easier time getting a compression tester than a boroscope, although if you can get one, great time to use it. Look inside for the exit path of the grounding strap and porcelain, lucky = ejected right out the exhaust path as valve opened / unlucky = chunked into the piston/head surface, although not an obstruction it will create hot-spots. Compression test is also a good option if you can.

Good luck with it.

 

I agree with CAT3 on this one. 28 degrees of timing was too much. It looks like it detonated. I would definitely do a compression test to see if its hurt. More than likely it is. My #6 plug looked just like that. I had a clogged fuel jet on the direct port. It melted the exhast valve enough to cause no compression in that cylinder. Good luck and I maybe your engine escaped unharmed.

 

I figured the white calk all over would have automaticly point to the leaness of the situation

 

Thanks for all the help so far.

I tried a compression test - didn't even hit 30psi. Where do I go from here? Pull the head?

 

Comp test or a leak down? If a comp did you test any of the other cylinders? If so, what were they at? If they were all tested good, then yup.

Matt

 

Comp test in that cyl was 30psi - tested another and it was 150

 

If you have access to a leakdown you could try that, you may be able to tell if it's the piston or hopefully "just" a valve. Either way though it looks like you'll be pulling the head.

Matt

 

Got the head pulled. First glance looks like just a valve. I'll post pics later.

 

Hope it works out for you. I blew all 8 of my plugs trying for 9's on a NA Tune, I lucked out, hurt nothing but the plugs. Seen my buddies after blowing out two plugs, and chunked the head, blew a valve etc...

 

OUCH!

I see so many trying to spray to much with out tuning here. Was automatic for us to dail it in on a dyno

 

Did it melt the exhaust valve? My head is at the machine shop right now getting a new valve put in it. Good luck with it.

 

It looks like it is broken to me. It also took out some of the area around the spark plug hole. Cyl walls and piston look fine though. I'm going to take the head to a machine shop today.

Thanks for all the help. One last question - what should I do from here? Down it to a 50 shot until I get timing tuner, then keep it at 100 shot until I get fuel pump? Not spray at all? 100 shot fine for now? 150 fine after the timing tuner, just keep an eye on fuel pressure?

Thanks again.