Here we go........I need to explain what we're looking at first. This is the Zilla'* motor less than 1000 miles ago:
Notice the rim of the piston above the rings is flat, and the piston is cupped in the center.
Off topic, first pic shows what a GOOD fuel pump and FPR can do. 2 days since this pump has seen power or pressure. Still holding fuel pressure:
On to the problem:
You're looking through the spark plug hole of the #1 cylinder. The 'cupped' portion of the piston is the dark to the left. Cylinder wall is to the right. The jagged 'cut' from 2 o'clock down to 6 o'clock is a break in the piston. The area below that is the top piston ring.
Molten aluminum from the piston disintegration in the CENTER of the piston 'cup'. This would not move when the borescope pushed against it.
Here you can see the large bright area is the piston 'cup'. the smaller area to the upper right is the exposed upper ring.
the bright area is the ring. The dimmer area is the piston.
Borescope in the #1:
Bo and Griffen have patience. They look forward to a newer, stronger, louder Zilla:
Now let me get on my soapbox:
This car ran PERFECTLY on 92 octane pump gas with a 2.3" pulley on a Gen 3 (94/95) top end. Why? Because of MASSIVE porting, rockers, and all the supporting goodies. But ONE tank of 87 octane due to a gas station rookie cost me my motor. This motor ran with ZERO KR on 92 pump gas on a HOT day. Matt and Slayer will testify to this. Even with the 2.2, we only had random knock counts, and no KR.
Let this be a lesson to every L67 owner out there that chooses to save a buck by running lower octane.