Although cast iron has enjoyed something of a resurgence since the advent of compacted graphite iron (CGI) in passenger cars, in racing it is an anachronism, a throw-back to much earlier times. It is usually used for large structural castings only where regulation mandates it. Otherwise, aluminium is the material of choice. Aluminium combines low mass and reasonable strength, and it finds use for pistons and all sorts of other components. The specific modulus or specific stiffness of...