The first public preview of a new series of common-rail leisure-marine diesel engines in the 400-500mhp power sector is presented by Yanmar Marine International (YMI) at the this year's Cannes' Festival de la Plaisance, September 8-13. YMI, in conjunction with its French distributor Fenwick, is unveiling a preproduction six-cylinder 6LY440 unit with one of the highest power-to-weight ratios in its class at the Mediterranean's premier in-water boat show.
The new 6LY440 is rated at 440mhp at 3,300 rpm and is one of a new 6LY2-CR family of inline six-cylinder units which 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.
The new model has a power-to-weight ratio of 1.7:1 (kW per kg) giving it not only a significant advantage over the previous 6LY models, but also outstripping the offering of all of its major competitors in the leisure marine propulsion market. Deliveries of the 6LY440-CR engine, along with those of a lower-rated 6LY400-CR at 400mhp, will start from early next year.
"If performance power cruiser owners detect something familiar about this new engine, that's quite deliberate on our part," said Wil Botman, YMI Assistant Sales Manager. "The engine is a development of the mechanically controlled 6LY2A engine series which have sold in several thousands over the years earning classic status among their many fans. In fact, it uses the same narrow and lightweight LY2 block which made it a favorite for installing in small, cramped engine rooms that are often found in boats designed for high top speeds."
However, just about everything else concerning the new turbocharged 6LY engine is new, the manufacturer said. Single mechanical injector units are replaced by a Denso digital 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 newly-designed inlet and exhaust manifold for optimal engine breathing to give high levels of torque throughout the entire speed range. And, of course, engine operation is fully digitally controlled," Botman said, making it ideal for fly-by-wire operation - as the market expects today.
This new common-rail six-cylinder diesel is complemented by a representative selection of the Yanmar electronically-managed JH-CR series engine models of 45-110mhp with common-rail fuel injection that meet the latest EPA Tier3 and upcoming EU RCD (2017) emissions requirements.
These new JH-CR four-cylinder engines have only been on the market since earlier this year and are the smallest marine diesels to offer the considerable advantages of electronic control over standard mechanical control systems, Yanmar said. "They are, by a distance, the leanest and greenest marine diesels in their class," Botman said, "currently being best in their class on five counts: they have the cleanest exhaust emissions; the best fuel economy; the quietest and smoothest running for comfortable cruising; best power-to-weight for superior acceleration and braking performance; and the best plug-and-play electronic connectivity."
On display from this range are the naturally-aspirated 4JH57-CR (57mhp) shown with the company's SD60 sail drive and the turbocharged 4JH110 plus (KMH4A) down-angle gearbox.
Like all new Yanmar electronic engine models introduced since 2011, the latest units have the full benefit of Yanmar's Vessel Control System (VCS) - also presented on the stand. This plug and play control system offers the company's advanced joystick system as an option for fingertip control low-speed maneuvering and docking by vectoring the outputs of shaft drive and stern drive vessels and thrusters.
Also on show will be the common-rail 4.46-liter V8 diesel 8LV370Z which develops 370hp at 3,800 rpm and is mated with a Yanmar's own ZT370 stern-drive renowned for super-soft gear shifting; the lower-revving 6BY3-160, 3-liter six inline inboard engine (160mhp at 2,800rpm) for larger displacement yachts; and finally the baby of this display and the only one still to have direct fuel injection, the 3YM30AE three-cylinder 1.266-liter unit which gives 29mhp at 3,200rpm.
"With so much that's new and groundbreaking coming from Yanmar in terms of boat engine development these days, we had no option but to double our stand size at Cannes this year," said Alain Moineau, Fenwick Marine Department Manager. "Its full range of integrated propulsion systems with modern marine engines from 9 to 480mhp for leisure and light-duty commercial applications reinforces YMI's position not just here in France, but worldwide as a leading market player in this power segment," he added. "I'm sure that the latest 4JH-CR and 6LY2-CR series engines, with their compact size and matching footprints to their legendary 4JH and 6LY mechanical forebears, will be of great interest to the customers seeking to buy a new sailboat, displacement or planing cruiser equipped with state-of-the-art technology, but also to boat owners who want to repower their existing craft."