Why screw around with casting engine blocks out of molten metal when you can carve one out of a solid billet of aluminum? For one thing you would likely need a Matsuura 5-Axis Mill. The crew over at Toolmonger posted up this video of the 5-Axis in action, in case you're thinking about picking up one of these babies for the backyard instead of a that BBQ patio set. [Thanks to Jon for the tip]