A Honda NRI saw at a show a while back.

This motorcycle doesn't look too weird on the outside but the engine is definitely pretty weird. It is a 4 cylinder in a V configuration and the pistons are oval shaped with 2 connecting rods per piston. The last picture is a model of the pistons rods crank and valves. These wew about $50,000 brand new back in the early 90s and go for over $100,000 today.