Disassembled the engine in-place. The turbo is in perfect condition which means nothing went through it. The front cover was removed, then the head, then the #2 piston. The cylinder walls were in amazing condition – the hone crosshatching still clearly visible with no scuff marks in any cylinders, even in #2. The #2 piston showed some sign of impacting the valves though the valves don’t appear bent. The head will be cleaned and fully checked out, then reused assuming it’s not cracked.
I sent closeup pictures of the cylinder and piston to the engine builder and he suspects I had a fuel or ignition problem. The injectors will be sent out to be flow tested and cleaned. I don’t really understand how a lack of ignition could cause high heat, but what do I know.
The reason the engine was disassembled in-place because since the turbo is being moved; the exhaust manifold flange’s location must remain fixed until it’s mocked up. Moving the turbo closer to the exhaust ports greatly reduces the surface area of the manifold and feeds more heat into the turbo instead of the engine compartment. The car’s been running without a muffler for many months because of how well the turbo acts as a muffler, and it finally occured to men that not having a muffler frees up even more space for the new intercooler. (If I ever run the car at Laguna Seca with its 92 dB sound limit, an external muffler will be temporarily attached.