Well it seems my logs from my HP Tuner and LM1 WB weren't lost after all? So I have been able to pinpoint the issue that caused the melt down.

First the a/f was fine as you can see in my LM1 WB log capture. The first few lean spikes are shifting going for 4th gear. Then you can see it go rich which is where 1st stage comes on. Then next lean spike is where 2nd stage hits, but is less than 1/2 sec so no worries. The lean on the end of run is on decel. But the full run was in the high 10.x:1 area, so we no it's not a lean condition as many said (not me cause i was watching this log). here it is.


I believe these 3 things conspired to cause my motor to go, as I had thought.
1-Timing: you can see in the HPT log capture and the Histogram (below) that timing at activation was at 26* (remember a 285rwhp shot). I had set my normal timing of 22* to have an additional 4* pulled. Well it looks as though I added timing (see the 26* on histo, and 25.5 on HPT), at least down lower. My fault for not checking my wonderfull work. I killed the "Magic Motor".



2-The TR6 plugs. To hot for this size shot in my opinion, and especially with 26* of timing. That's why they all melted down.

3-Running only 101 trick instead of my usuall 104 octane. I buy the 104 by the 55 gallon drum so I know it's good. The 101 came out of a pump, and some have had problems with quality.

So going as big as I did, the cylinder pressures were very high, and add the cobs of timing, well that's how the ring land broke, then detonation took over and melted said piston. Now i believe if it weren't for the timing being jacked up, the plugs may still have melted down, but likely the piston would have survived?


Anyway the moral of the story is, allways check the changes you do in the tune/pcm. Don't take for granted all is well, I did and lost. As Dave said in the other thread, KR does not allways show and/or tell the story, and it did not show more than 1.5 degrees of pull. My normal cautious, deliberate ways were neglected this time and I lost my motor. If I would have only checked my tune on a smaller hit I believe we would still be running this motor at 285rwhp shot. Oh well, we live, we learn.

Edit: For those that may not have seen the original thread with dyno vids, pics and dyno sheet, here's the original thread.
Up in Flames
Robert

 

Ouch! Im hope you got a new motor in plans! Should be fun to see!

-Lurius

 

Yep...looks like you have it figured. I would say you are right on.

Sucks...it was due to an oversight. But its not the end of the world. Actually it does show just how damn tough these stock shortblocks are. I really think 700 rwhp is doable with all the ducks in a row.

Also...look at it this way. When someone like you melts a motor...and then uncovers the reasons for it...there is generally alot learned. I am absolutely sure you have a much better understanding of limits and where they are. Limits are no longer a fuzzy abstract...but a hardcore known reality.

I went through this exact same scenario and I know I learned a TON because of it. Sometimes I think people dont really take limits seriously enough until they have a serious mishap.

Welll...get to work on the new 427 ETP headed solid roller with 3 stages!!!

 

man i totally agree. a couple weeks ago i changed some tuning cells and and ran a 200 whp. everything i checked looked good except after the run a looked at the log and saw 30 degrees of timing. the only thing that saved me was my standalone i fabbed up. im thinking about upping my shot. ive run a 240 rwhp before and maybe ill pickup where you left off. we have a dyno day coming up and i should be 640-650 rwhp, stock short block still. only difference in our setups is you multi staged and im running a progressive.

 

I agree man. You had a convergance of a perfect storm. Messed up timing(26 way too much for that size shot), different fuel, and plugs that are a bit too hot.

Well at least you know what caused it.

 

lol speaking of perfect storm, a month ago, i was running a cobra 700 hp suppose to be, had 27 degrees of timing on a 175 shot, lost the 40 fuel jet so i went with a 38, and on top locked the converter to get more to the ground for the race. make a long story short my ls6 intake is scattered all over the interstate. but i believe what robert says, these things can take 700 rwhp but you need to have everything triple checked. any human error and boom.

 

Ouch that hurts, but answered a question that has been lingering in the back of my mind. I have been running 20.5* of advance on a 125 shot and bumped the timing up to 26* but am going to change it to 24*. Does everyone feel that 24* is safe?

 

I ran stock timing on a 150 shot with just boltons, never had a problem.

 

Great post Robert!

Thanks for helping us learn from other's mistakes.

 

At least you know what to not do again. Thanks for the update.

 

"jumping back on the horse" is always good in theory... it's hitting your nuts on the horn, that you really remember.

Keep us updated on the new build.

btw Robert, I have a pretzeled connecting rod out of my old LT1 that would go great with that piston. Just have to take some engine block shrapnel out of it first.

 

24* is fine with the 125 jets

 

Same here, but I would always have 2 or 3 gallons of 110 in the tank just to be on the safe side.

 

Imagine how fast you'll go now.

 

I told you many many months ago to get those plugs out of that motor. Looks like it finally sunk in. With that much juice and cylinder pressure for your application an 8 was a starting point for you. Id have most likely ended up at a 9 or 10 on the juice. Lets see the rod bearings, cut away the threads on the plugs, and the chamber of the heads.

 

Also listening to that dyno pull that motor was struggling from about middle of the run and on...It didnt want to climb cleanly. Those are sure sign pointers of a hot soaked chamber.

 

it sucks that something so little lost your motor

 

great write up! Good luck on the next build!

 

Al, I only wish. Yea, 700rwhp may be doable, if the torque is kept in check.

cjg454ss, that's to bad, allthough if no other damage, an intake is easier than a short block.

V6 bird, yea I had planned on getting some plugs, before the 285 pull, but had spaced it off. I remember asking about it. All rod bearings are perfect. We couldn't believe how nice every thing looked. heads are fixable, and no seat was damaged with 7 plugs melting down, go figure. The only head damage was some gouging from the ring land piece.
Yea I could feel/sense something was wrong from the get go, but I have a motto of never getting out of it. Great motto huh, it allmost put me into the wall at 100mph a few weeks prior.

Thanks everyone for the words of encouragement. We will be back, soon I hope.

Robert

 

I would just like to point out the engine was running in the corner at the bottom right...not where you have it circled

Maybe you should have lifted when we were all waving our arms at you