printing the engine in one piece, making a mould based on that and casting in alloy of choice is a vision of mine. that would enable to make the flow systems, engine itself etc without joints that would compromise strength and weight, make the changes in engine design fast on the 3d model and give the ability to make more complex designs without increasing the construction difficulty also the price gain is important. reprap would enable to design such things on a freeware design method where various interested participants from around the world work on a common purpose. before designs of machines and other physical objects had to have a team brought together in one place reprap would eliminate such a problem and enable enthusiasts to work on a large scale project