YThe 4LV engine range launched last year by Yanmar is now being offered with their twin-prop ZT370 sterndrive. This compact 2.7L 4-cylinder engine comes in five outputs – 150hp, 170hp, 195hp, 230hp and 250hp – and with sterndrive fitted weighs in at a sprightly 446kg. All variations will be available with the ZT370, which, fitted with a hydraulic multi-plate clutch similar to that of a motorcycle, offers relatively seamless transmission. Though this sterndrive has been out for a few years, in sterndrive terms it is quite unique, and ideal for joystick use where the drives are having to quickly change rotation. Having been originally developed for Yanmar’s punchy 370hp 8LV 370, it is more than capable of dealing with the smaller 4LV series.
Both the 4LV 230 and the 4LV 250 produce impressive levels of torque,
with outputs of 390ft/lb and 420ft/lb, respectively, from 2000rpm to 3000rpm.
Both these engines rev to 3800rpm, while the lower-output versions redline at
3500rpm. This compares well against Volvo’s bigger 260hp 3.7L 660kg D4 with duo
prop, which puts out 450ft/lb from 2000rpm to 2500rpm before dropping to 430ft/lb
These engines feature the latest in electronic common-rail fuel
injection. They are also built with what is termed ‘Thermo-Swing Wall
Insulation Technology’, providing maximum thermal efficiency, which creates
better fuel combustion and efficiency. In simple terms, this means the internal
combustion chamber retains a higher degree of surface temperature, producing
better diesel combustion. In the automotive industry, this has been achieved thanks
to a special treatment of the piston crown, and a similar principle may have
been used by Yanmar.
Emissions are consequently reduced and torque increased, Yanmar claim. The ZT370 is manufactured with an ‘EXO hard-anodisation’ skin to provide extra protection against corrosion, and is offered with a variety of gear ratios, thereby ensuring its compatibility with a wide selection of craft. Other features include precision-forged gears for extra durability, and there is the choice of electrical or old-school mechanical controls. All engines are available with Yanmar’s JC10 joystick system and all are NMEA 2000 compatible. All models exceed EPA Tier 3 and EU RCD Tier 2 emission regulations.