A ship I worked on many moons ago had opposed piston engines(horizontal crankshaft on top,horizontal crankshaft at the bottom,joined together with a vertical shaft driven by bevel gears.Each cylinder(10 I think)had top piston and bottom piston fighting over the same hole.Supercharger fed the air into ports opened and closed by the bottom piston,blowing exhaust out ports opened and closed by the top piston.Cranks were slightly out of sync,lower end leading,I think.Pistons met in the middle,fuel injected,boom.Two cycle operation,and they were FILTHY inside with lots of interesting things coming out the stack up top. No white dresses on deck,please.I'd like to see this new engine running,and see what kind of ooomph it will produce.