Way back in 2006 and 2007 we wrote about the Neander turbo diesel engine and the motorcycle built around it. The engine's design was unique due to its counter rotating crankshafts with a pair of connecting rods, one from each crank joining together to drive a single piston. It was a great way to eliminate the vibration normally associated with diesels and it looked like a fine design overall, but the motorcycle industry didn't respond in any measurable way and Neander faded from the spotlight, but as a company they kept working on the engine looking for other applications. It looks like they found a winner, the Neander Dtorque 111 outboard engine. Neander-Shark announced it will be built by Steyr Motors of Austria and distributed by Yanmar Marine.
As configured for outboard duty, the engine is an 804cc, 50 horsepower, 111 Newton Meter (82 pound feet) twin cylinder turbo diesel. The engine's crankshafts are oriented vertically and at the centerline of the engine the rotational forces are balanced eliminating torque steer and the expected vibration of a small diesel engine. It uses about 35 percent less fuel than a comparable gasoline engine and has as much as two times the expected engine operating lifetime. It's smooth and quiet and it has lower CO2 emissions.
It's good to see this engine developed and now being manufactured in significant numbers. When smaller engineering firms come up with promising designs, it can be a long road from initial concept to commercial production. The motorcycle market may not have been the best fit, but this outboard engine seems to be the perfect application for a great idea. I hope they see huge success.
Neander Shark and Yanmar Marine via Newatlas
Meehawl says
I was looking for a decent diesel outboard back in 2001 to repower my fathers yacht, that had been sunk by some inept Egyptians in the Red Sea. He’d refloated it, towed it ashore and rebuilt it in a fetid little desert town in Southern Egypt. The little 40hp Lister Petter he had in it was now buggered and I toyed with the idea of using a powerhead off a diesel outboard attached directly to a Sail Drive, mounted on a rotating plate, eliminating the need for any gears beyond reduction and able to then also be employed as a stern thruster. There was nothing decent back then at all that I could find and I always wondered why that market niche was left empty. Now I know. Cheers Senor Kneeslider, another piece of the great universal jigsaw puzzle has been revealed.
Rod says
I was thinking maybe they did this as much to eliminate the need for piston skirts and slap (which are responsible for a lot of friction, particularly in long stroke diesels) as for any other reason. Sure enough, the web site of the developer mentions both the elimination of vibration and piston skirt friction. I would worry a bit about gear lash and so forth, but the site makes this interesting statement: “The key enabler for a dual crankshaft engine with a constrained piston movement by two con-rods with theoretically no piston side forces is provision for forgiveness towards tolerances.” Maybe they’re referring to the reduction in tolerance needed to accommodate piston tilt in the cylinder? In any case, it’s good to see innovation in internal combustion by small operations continues.
https://www.neander-shark.com/en/technology/
Del Vinal says
The safety of diesel fuel vs gasoline on board boats might lead to less costly insurance too. 35%better fuel eff. of diesel vs cheaper gas is a savings, and if the ins. would be less, yeah do it. Fire from the fuel leaking out somewhere is a major concern at sea, so that is a huge win for diesel.I read somewhere the longest ocean voyage for outboard power was from cali to Hawaii, a Nissan diesel pair that was going there as freight. The vessel engine took a crap, and the crew jury rigged the 40 HP Nissan’s on somehow and kept on. Now they need to get into the 200-350 hp range.
Marcus says
Now it’s up to us to fiddle with two Harley V-twins and turn them into a twin diesel motor!
Marcus says
Doh, I wrote that over a beer. Two inline twins will do better to achieve the desired effect.
Jiro says
weight?