After disassembling the engine, the piston has no damage. The crankcase has a few superficial scratches, but I do not think that they would effect the engine, as they do not go into the crankcase. They are merely superficial . let me know if I am wrong on this one. Thanks for the help!

So, if my piston is not damaged, what can be the cause of my engines poor performace post-crash? Thanks