I was looking at a video of an antique briggs and stratton L head engine and wondered about what would happen if you had two custom L head engine blocks mated together, but oriented 180 degrees so that the valves in one block sit over the cylinder of the other block.
Then there would need to be a spark plug pointing up from the block near the valves.
Then the crankshafts would be geared together somehow, like a deltic or split single engine. I guess one camshaft would be different as one crankshaft would be turning the wrong direction, if you wanted them to balance that is.
I suspect it would be very high performance since the mass of the valvetrain is quite low, comparable with a modern single overhead cam, but with a vintage capable design.
Cost would be high due to the need for two cams and two crankshafts, but the components would be less, since there's no head. Not exactly a profitable design, but it is a curiosity to me.
