this is what i found after i tore down my engine. it blew on a mis-shift from 1-2-5-3. stock gsr 14lbs on a t3/67. motor never had any problems afr was 11.4 with 93/c16 mix. timing was ultra low at 12 degrees. just trying to learn from this and blame it on the missed gear. lol

 

well this is what it looks like. The piston got s hot spot and it melted down. I believe this is duw to the stock pistons gaining hot spots right around the compression rings. Thats what it looks like to me. It happens cuz of boost, I would point the finger at the lean mixture, but you said your stoich was fine so no idea

 

it happened because you forgot how to shift

 

bad injector in one cylinder

 

would help if the Pics were focused at least

 

What do the rest of the pistons look like? Did they all melt?

 

ok newbie if you didnt know the answer next time just sit quietly in the corner. that way we wont know exactly how dumb you are

i was thinking that.

tried that sorry.

no just number 3.

 

since your timming is super low and afr seems to be okay..

Could be: injector, or just an old engine

 

extra low timing produces high temp in cylinder is it not? but 12 isn't ultra low. lol just low.

at 14psi on ur turbo, its around high 300whp.
maybe those pistons can't handle that power.

the misshift is okay.
1253.
i assume you accidentally put it into 5th, then put it back to 3rd immediately.
so its still not over rev.

 

yea i knew i was pushing its limits but i didnt expect to see it melted. i assumed just the ringlands.

 

 

looks like it was caused by ring wash. happens when rings go bad and gas gets in the rings. causing the combustion to happen in ring glands. just my 2cents

 

How do you blow a motor going from 5th to 3rd?

 

i didnt

 

Whats this mean then?

 

Sounds like a bad injector.

 

bad fuel injector if it was only that one cylinder.

oh.....and running "super low timing" is not necessarily "safe"