There is a good chance of that.. but it's not definate. I would break the engine down and take a look inside. If there isn't any damage yet, there very well might be soon if you keep running it. The gap in the number 4 plug should NEVER be closed completely off like that.

PM me with your mod list and description of what happened and I'll do my best to lend some advice.

Good luck!!!

 

No telling what happened. The plugs are impossible to read since the car was run after the full throttle pull. Corey told me this morning that the electrode is broken loose, this makes it hard to tell if the strap is bent or if the electrode is cocked and just touching the strap.

The car was tuned on 110 octane of "X" brand and then switched to Sunoco 110 octane, the difference shouldn't be enough to matter.

I know when we tuned the car last week we had the AFR set at the leanest point around 11.8 : 1. The knock count on the 110 octane fuel and 23 pounds of boost was under 1.6.

This should have been conservative enough to never hurt it.

No telling what happended. Looking forward to getting the maps from you, we just got off the phone. Hopefully you only changed the low end of the map like you thought you did after you left.

I don't believe there is any damage done internally. Too much of the plug is still intact and you said the car runs great after putting in the new plugs.

David Buschur
www.buschurracing.com

 

Well mine was the same. Cause was a broken piston ring sitting ontop of the piston and slamming it shut. Have picture and everything of what happened.

Chris

 

I dont want to be the bad news guy but i can almost gaurantee you have a broken piston or ring or somthing sitting ontop of your piston. Same exact thing happened to me. Went through 2 sets of plugs figuring it out. I then did a compression check and number 3 was a little off from the rest. I pulled the head off just to find the damage. I got lucky and the head did not have that much damage a couple of bent valves and some nicks in the head itself. The block was fine but i got it bored and honed .20 over just to make sure. Needless to say the outcome was blueprint and balance crank, crower rods, ross pistons, sodium nitrate vavles 1mm over, Buschur Valves springs and retainers, cams, ect...ect... I think in the long run it was well worth it just more of a pain in the a$$ if you know what i mean.

I can get you a deal on the Ross Racing Pistons depending on your outcome.

Chris

 

Had a calabration test done, no leak down. And the results came back like this, 175(1st valve), 175(2nd), 175(3rd), 165-170(4th). Is this much to sweat.

 

No i belive that is within specs. But mine came back the same. It was just slightly off like you see there. I would try and pull the plug on 4 and with a flashlight see if you can see any visible damage or pieces. Otherwise get a scope and see if you can look in there. Or if you are mechanically inclined just pull off your head and get a real good look. Its not that hard to do and that will be the best diagnose you can do.

When i did mine it was 140, 130, 140, 135. Pison 3 was the one with the ring missing and a chunk taken out. Pison 4 had a crack all the way across it. Those numbers are lower becouse of the cams i had at the time by the way. Anyway i can send you the shop manual if you want to pull your head off so you have detailed instructions. Just a thought. Otherwise i wish you the best

Chris

 

Yea, you need to scope it just to be sure, just like Chris said there could be pieces of broken rings and/or ring land materiel bouncing around in there. You do not want to get a piece of a ring stuck between the intake valve and seat and backfire through the intake system and turbo.

 

Yea thats what happened to me. Damn piston ring went through turbo. Come to find out you can not just buy new fins for the dual ball bearings turbos you have to buy a whole new center section which sells about $200 cheaper then the whole damn turbo. SUCKED!! Anyway i really think you should scope it or pull the head off you dont want to cause any more damage then it possibly already has. I can send pix of my damaged plugs for you to compare just let me know your email.

Chris

 

I sent you a PM. Where can I get a scope.

 

I had about 1/4 of an exhaust valve make its way through the stock turbo. History.......

 

On a slightly off note if the Sunoco fuel you are running is the same stuff we use in Nascar and ALMS you need to be careful of fuel lines and any other rubber parts thats come into contact with it. According to a Sunoco rep. that gas can have anywhere from 5 to 30 percent tolulene in it (depending on where you live) and it is hard on rubber parts. You would be amazed at how different it is versus the 76 fuel we used to run. It has been eating our fuel lines and all sorts of other parts.

 

took the car out for a drive today and no prob. After the compression check.

 

I dont like Sunco. I mean its ok but i have found that the dies they use have a tendancy to seperate after awhile. Which means say you had it in a drag bike "this is how i found out" and i let it sit for the winter when it came time to let her rips agian there was power all built up into the carbs and everything from the gas. Looked like baby powder. Ever since i run VP i think it is allot better and has higher ratings. Problem with it is it cost ALLOT!!!

Chris

 

im getting a studder/backfire, but no bent plugs. but my plugs are more of a grey white color. my afr is set to 11.0 or richer. shouldnt my plugs be blacker at that afr? i thought whitish meant too lean. btw, what are other charachteristics of detonation?