An entire engine? That sounds like a marketing plot. But if you take smaller chunks let's say the shape of a combustion chamber or the shape of a intake or exhaust manifold. It's going to take white noise and just start pattern matching and monkeys on typewriter style start churning out horrible pieces through a simulator until it finds something that tests out as a viable component. It has a pretty good chance of turning out individual pieces that are either cheaper or more efficient than what we've dreamed up.