Yanmar Marine International (YMI) is showing its entirely new range of common-rail fuel injected marine diesel engines rated for leisure marine and workboat applications at METS 2015 (RAI Amsterdam, 17 - 19 November) on Stand 01.331. Topping the bill of new inboards is its in-line six-cylinder is rated at 440 mhp at 3,300 rpm. This is the world marine-trade debut for the new unit, which will also be offered in a 400 mhp version and will go into full production early in 2016.
Although new, the 6LY440 and 6LY400 have a distinguished pedigree derived from the mechanically controlled 6LY2A engine series. During its nearly 20-year long production run it was bought by thousands of performance-cruiser owners around the world, earning an enviable reputation for quiet and smooth operation, fuel efficiency and reliability.
The new engines inherit their predecessors' narrow and lightweight block whose compact profile enabled it to be installed in small cramped engine rooms. Nearly all else is new, however. Single mechanical injector units are replaced by a Denso digitally-controlled common-rail fuel injection system with new pipe work designed to cope with higher injection pressures. The 24-valve cylinder head is all-new too, as is the inlet and exhaust manifold designed for optimal engine breathing and high torque output throughout the engine's operating range.
The electronically managed engine is also designed with all the benefits of plug-and-play operation, using Yanmar's Vessel Control System (VCS) which gives the options of wireless controls and fingertip low-speed manoeuvring with the company's advanced joystick.
"The new common-rail 6LY engines build on the Yanmar tradition of producing state-of-the-art compact and powerful marine diesels that are class-leading in performance, fuel-efficiency, low emissions, and smooth, quiet and dependable running," says Floris Lettinga, YMI Global Sales Manager. "The 440 mhp version has a power-to-weight ratio of 1.7:1 (kW per kg) and is not only an advance over that of the previous 6LY models, but is also ahead of the like-for-like engines all of its major competitors in the leisure marine propulsion market today."
Other new common-rail diesel engines on the YMI stand include four-cylinder models from the company's electronic JH-CR series engine family. Launched early this year, these span the 45-110 mhp power range and are the smallest CR-injected inboard marine diesel engines on the market.
"The first customer responses to these new engines have been overwhelmingly positive," Floris Lettinga says. "We asked several boat sales managers and all were unanimous that these engines set a new standard. The combination of less vibration, inter-connectivity with chart plotters with added functionality, and not having to deal with exhaust gas fumes is truly remarkable, they tell us."
He adds: "Those who have already got to know this new engine family say that, without any doubt, this sets a new standard in sailboat auxiliary propulsion. Not one of the sales managers whom we asked wants to go back to mechanical fuel injected engines. No longer will they need to explain to boaters that they have to accept exhaust gas fumes and can't enjoy the electronic connectivity that they have come to expect in their home environment!"
The common-rail theme on the YMI stand is rounded out with the 4.46-litre V8 diesel 8LV370Z with optional joystick control, which develops 370 mhp at 3,800 rpm and is mated with a Yanmar's own ZT370 stern-drive renowned for super-soft gear shifting with its specially-designed hydraulic clutch.
All engines on display meet the latest EPA Tier3 and upcoming EU RCD (2017) emissions requirements.