Huh? melting point of aluminum is at 660C, brass even much higher so how would it melt at 229C

About combustion temps: http://fluid.wme.pwr.wroc.pl/~spalan...combustion.pdf

Yes, the oil is not the the one that combust but because it is within the mixture and on the surface of the piston it will be in the flame of the combustion and burn.