Well the engine is out and the offending piston has been analysed. It looks to have had a massive failure and cracked the ring lands off!
The good news is that it doesn’t look to have come from extended periods of detonation, so just the stock hypereutectic not being up to the job. Regardless of this we’ll be modifying the fuel system to run in parallel with an Aeromotive FPR taking over from the stock item just as an extra security measure.
The old setup:
The rest of the components were all in good condition so it looks like the engine was nice and fresh, bar the one piston.