Yanmar has just introduced a new common-rail diesel engine in the popular 400-500-hp range for larger cruising boats. The new in-line, six-cylinder 6LY440/400 is the fourth generation of classic Yanmars dating back to 1989, all designed specifically for marine use. Since it has the same slim block as earlier engines in the series, it’s a good choice for both OEM and refit applications.
The new 5.8 litre engine develops 440-hp at 3300 rpm, getting extra boost from a water-cooled turbocharger; other engines in the series are rated at 400 and 370 hp.
Like all Yanmars over 45 hp, the 6LY440/400 now has common-rail fuel injection instead of traditional mechanical injectors. New pipe work handles the higher pressures of common-rail injection; the engine also has a new 24-valve cylinder head plus a redesigned inlet and exhaust manifold to enhance breathing.
New sophisticated digital electronics control the engine, while Yanmar’s Vessel Control System guarantees optimum performance and fuel efficiency; VCS also interconnects with the ship’s other electronic systems and gives the option of joystick control.
Earlier versions of the new engine earned legendary status for their “performance, reliability and durability,” says Floris Lettinga, Yanmar’s Global Sales Manager, “and it still widely regarded as one of the best marine engines in the world for cruising.” She said that Yanmar expects to see that tradition continue, in new boat applications as well as in refits, “where its high power density and compactness will make it an engine of choice.”
Yanmar says the 6LY440/400 has a class-leading power-to-weight ratio of 1.7:1, and it meets U.S. EPA Tier 3 emission requirements.