If you don't mind me asking whats the labor cost involved in rebuilding the LS6 back with the parts you are getting for $1200? My goal is to push my LS1 to the limits and plan to rebuild it if I have an issue.

 

Not sure on labor. If I go this route I will be building it myself.
Robert

 

yikes! oh well looks liek its gonna come backe even better

 

I have tore my personal car up on the dyno getting in a hurry as well on a big shot... I think it is a process of learning we all go through to broaden our knowledge..

When a motor goes to that point it is hard to read the plugs. The pictures you are showing are alittle misleading on looking at the plugs as well. However this is what I am seeing. Looking at the smooth base ring of the plug they are charcoal Except for maybe one ( a full color change) That shows ok airfuel. The second one in the picure is showing some silver on top of the base ring. This could be from your fingers wiping the plug. If it is not that plug is lean.

Back to my original post about trying to tune watching for knock. This is why we do not tune with that method. Watching for knock is a nice tool but taking a car to where it picks up knock and then backing it down alittle can be very harmful.
Reading the plugs is the best way for tunning but is becoming a lost art for some. Looking at your piston there was deffintly detonation. By reading the plugs you could have caught early signs of detonation that the computer had not picked up. Early signs will be shown on the porcelyn of the plug. This will require a magnified light in order to catch it in the early stages. As the detonation becomes worse the specs get worse. After awhile it is to the point you do not need the magnified tool to see.

I am thinking your problems mostly were in not a cold enough plug and to much timming. For around a 300 shot which is what you were close to, a one step colder plug than the TR6 would have been idea and starting the tune you should have been around 14 degrees total timming. Then by reading the strap on the plugs you would be able to see your timming mark. By following the timming mark you could see if the car needed more timming rolled back into it.

The good news is that the damage is really not that bad. It could have been much worse.
Dave

 

Dave,

Do you know of any good documents on reading plugs? If not would you be willing to create one?

 

The Larry Meaux article is a decent one for a starting point. Only down side is that it doesn't show all the variations you'll see through the tuning process. Unfortunately, I never found anything all inclusive except for experience. There's nothing better than doing a track rental for a tuning session. Making a hit, pulling all the plugs, reading, making an adjustment and starting the process over again will take a lot of time but it will teach you tons. The first time you use a magnifier and tune to where you see a ball of aluminum where it is attached at the bottom of the porcelein you'll go, ahh that's what I'm looking for.

 

Actually, I am in the process of wrighting a very detailed How to on reading spark plugs. It will have very detailed pictures to teach anyone how to read plugs from start to finish. Like Next said I have found some on line but nothing that really covered everything perfectly.

I will see if I can find the links I Have saved on my computer as soon as I catch up.
Dave

 

That is a great idea! Now here is the issue I have with reading plugs........

After a drag run down the strip, you still have to drive up the side road to get back to the pits. That ruins the plugs initial run not allowing you to check the plugs. So the only way to read plugs is to have your car on a dyno and pull them after each dyno pull.

For the average Joe like myself, we don't have dyno's to do this with, so the only other method is to illegally run the car on the street then pull over after running the car to check the plugs.

Do you have any other inputs on this Dave???

 

Actually you can Do it at the track fairly easy.
Idea is to 60 ft, then 8th mile and then quater mile the car shuting the car off right after the pass. Then coast to the side and pull over on the return lane. Pull the plugs and replace them with some spares in the car. Then go back to the pits and read the plug. Or pull it back to the pits with a 4 wheeler or golf cart.
Dave

 

Good insight Dave. yea reading plugs is becoming a lost art. When I got my start racing/rodding that was your main tuning tool-readin the plug(s), we had no dynos or logging/tuner programs. However, with all the tuner programs and such, we (myself included) have got a little lazy and dependent on the logs. Well, I am not behond learning, or re-learning, and have gained some valuable insight on tuning a big shot. As Al stated, any errors or issues become maginified when at these levels. I look foward to seeing your plug write up. I have the basic concept, but no expert for sure at plug reading. Here is another pic of plugs with a survivor, can you see any additional info? Thanks
Robert

 

Got to get a magnifier. With your times/hit, you have your tune down for sure.
Robert

 

Eh, unfortunately I had to learn the hard way but I guess those are some of the best lessons learned. I've got a 10x lighted, but wish I could find a 30x like my friend has.

 

Sorry to hear that bro..

 

Thanks, yea when I heard you were forging, I had to go that route also. The little forged LS6 will be ready for our first series race in about a month, so not to bad.
Robert

 

Haha I was right! That dipstick flying out screams ringland. At least its not that bad! With Dave's reading on your plugs saying the A/F looked close I'd say it was just too hot a plug and too much timing.....

 

So it wasnt a 285 hit. It was more, have you figured out what size shot it was? That was a stock bottom right down to the rod bolts? Have you checked for bent rods? Im supprised that those hyper pistons took that kind of abuse before it let go, Im impressed to say the least. Its really unfortunate that one persons catastrophy is anothers bible of what not to do.
The kit is rated at 285 rwhp what would that equate to fwhp?

 

You guys are some damn good drivers 10.7 @ 130 with just a 150 shot! Heck my car has never ran that with a stall and ~520 RWHP on a 100 shot!

 

GREAT cant wait.

 

Out of curiosity, besides running a rather hot plug (a TR6), were you running a fuel with at least a 99 Octane Mon (Ie. VP 109 unleaded, Sunoco GT Plus 104 unleaded)?

To me it looks like the plugs caused pre-ignition due to the immense heat on the plugs. You said the car went flat? If the spark plugs were glowing red, as soon as the A/F mix got into the combustion chamber and piston was heading up to compress, it likely ignited the mixture partially, very early on the compression stroke. We are talking up to 180 degrees BTDC! Also, with pre-ignition you will not hear ANYTHING. No marbles in a coffee can, no ping, nothing, just the motor will nose over flat like theres no power or little power.

Now, those cylinders experiencing this effect would be subjected to immense heat which is indicative on that melted piston. With hypereutectic pistons, they usually shatter under detonation. That piston was melted due to heat! The spark plug electrodes also show signs of melting due to heat.

I vote the spark plugs not the lack of fuel nor the size of the nitrous shot contributed to the untimely demise of this engine.

Tony

 

Tony makes a good point.
Eutectoid material cosists of alternate layers of ferrite and cementite resulting in a 0.8 per cent carbon composition. Being of Hyper-eutectoid steel and above 0.8 percent carbon its primary cementite and pearlite composition. = Very brittle. It didnt shater which leave high heat. For this transformation to take place the upper critical temperature must be met. For that piston to have melted the temp must have surpassed 1527 degrees Celsius.
brain overload must shut down....