Yanmar’s latest 6.7L 6-cylinder range offers great power to weight and efficiency.
Making its debut this summer, Yanmars’s latest 6LF series raises the stakes in terms of power to weight with this new three-engine range. Available in 485hp, 530hp and 550hp outputs, these motors are aimed at superyacht tenders, planing and semi-displacement motorboats up to 55ft, as well as the commercial sector. The top-of-the-range 6-cylinder 6.7L 6LF550, weighing in at 780kg, produces an impressive 82hp per litre of cylinder capacity – more than Volvo’s latest D6 440. Torque has always been a Yanmar strong point, and in this case the new 6LF550 excels with a whopping 800ft/lb of torque at just 1600rpm, peaking at over 1100ft/lb at 2000rpm.
In today’s world, power alone is not the single benchmark by which any marine engine can be judged, as efficiency is crucial, and here Yanmar seem to score well. They are controlled by the freshly launched next-generation Yanmar VC20 (vessel control) system, for a maximum of three engines, with up to four helm stations. They also feature Yanmar’s proprietary fuel mapping, and a larger mixing elbow for reliable and consistent output performance. With a maximum engine speed of 3000rpm, these engines are engineered to offer direct connectivity to NMEA and J1939 CAN bus networks. Having already been proven in a recent retro-repower of a big classic powerboat, these engines will likely prove popular in next season’s line-up of new-build engine options. As is to be expected of this company’s latest generation of diesel power plants, all models are RCD, IMO Tier 2 and EPA Tier 3 certified.