One of the benefits of running forged aluminum racing pistons is that they are malleable. Stock cast or hypereutectic pistons can handle large amounts of horsepower under perfect conditions, but they are also quite brittle. In an event like this, a hypereutectic piston would have exploded into a million pieces and there would have been a lot more shrapnel floating through the oil galleries. This looks bad, but it could be worse. Notice the almost perfectly round slug we pulled out of the oil pan that the exposed exhaust valve stem punched through the top of the piston.