That twin counter rotating crank on a two cylinder is a really neat configuration. Kudos to the guys that came up with it, although I suspect it may be an old concept.
Two cylinder four strokes have always been infernal beasts. You could choose to have the pistons moving together to get an even 360deg firing pattern, but that would leave to a horrible mass balance no better than a single cylinder. If you put big weights on the crank you can balance some of this, but with a single crank, any weights will also cause lateral forces which is just another vibe. Yuk.
You could have the pistons moving 180deg out like a two stroke outboard, that leads to better mass balance but in a four stroke now your firing pulses are way off balance (think Harley).
This arrangement fixes things. You have the pistons moving together so you get the even firing. The mass of the two pistons going up and down can nearly all be counteracted by weights on the two cranks. Since the cranks are counter rotating, the forces from these weights create no lateral forces, only up and down which is in the right direction to counteract forces from the pistons moving up and down.
Neat stuff.
Engine still is going to have a vibe problem at low rpm due to the high compression of a diesel and the low cylinder count. The fix is to set the idle rpm up, but that combined with relative low peak rpm (compared to a 6000rpm gasser) means that there simply is not a lot of rpm "room" between idle and cruise and full rpm.
We see this problem on go fast diesel boats with big engines; idle at 600, cruise at 1800, max at 2300. Nice to go fast at 1800, but that also means you are going pretty fast at 600!! Not fun in no wake zones and around the dock.
How social this thing is remains a question to me.
And I also think it is a niche product, when you critically analyze the cost/weight/performance/social skills/longevity factors it will lose out to the gasser outboard in most apps.
Still neat stuff...
