Yanmar 8LV Captain's Report

It was first unveiled at the Dusseldorf Boat Show, and made its stateside debut at Miami last winter. The new 8LV connects to either Yanmar’s outdrive, marine gear box, V-drive, or jet drive.

A Compact Package

Let's take a look at some of the features of this new engine. We discussed that it weighs in at 992 lbs (450 kg) lighter than many of the big-block gas engines it can replace. The light weight and small dimensions will allow this engine to fit in a variety of new boats up to roughly 45' (14 m).

If you were to do a side-by-side comparison with one of Yanmar's popular 6-cylinder diesels you'd see some close measurements. This 8LV is only 8.5" (21.6 cm) wider, 1.75" (4.4 cm) higher, and 3.4" (8.6 cm) shorter than the popular 315-hp 6LPA. In other words, this 8 cylinder engine can likely fit into any engine compartment that the 6 cylinder can, adding 55 hp and only 93 pounds of engine weight.

Thanks to the small size of the 8LV it can fit into more engine compartments over a wider range of boats.

More Details

The 8LV has an rpm range from 550-3800 rpm. It is a four-stroke, 4.5 L engine with 8 cylinders arranged in a 90-degree V. The injection system is direct injection common rail. The electrical system is 12v and it packs a whopping 180 amp alternator, which means that you can run a panel with more electronics without concern. The fresh water cooling is via an internal centrifugal fresh water pump, sea water cooling by a rubber impeller seawater pump.

The factory tests show that the twin turbochargers cause the engine to reach maximum torque at just above 2000 rpm. A flat torque curve like this is very desirable for strong throttle response. Fuel consumption charts show the best fuel economy is reached at about 3000 rpm, giving a nice cruise speed with good fuel economy, and power to spare if needed.

Yanmar has added a solid aluminum top cover. This will please every owner with a mechanic who lies across the top of the engine when servicing. All the components are within easy reach, and CAN-Bus technology includes an electronic CAN-bus control-head, versatile multi-function color display with NMEA2000 or J1939 gauge output, and an optional second station.

It’s All About Yanmar

One important aspect of this engine is that it's an all-Yanmar design, from the engine, to the drive, to the engine controls and displays. So what does this mean to you? Well, for starters, when one company designs and builds every component, those components are all engineered to work perfectly together. And having one service contact for everything on your drive system is a very attractive feature.

Sterndrive Compatable

This engine is perfectly suited for Yanmar's newest and beefiest outdrive, the ZT370. One important feature to note about this particular outdrive is that it has hydraulic clutches like a marine gear. This means two things: first, there is no cone clutch, which has been used since the introduction of the sterndrive in the late 50’s. Second, that annoying “clunk” as you drop the drive in gear, and the even more annoying “gear grinding” sound as you ease the lever into gear, are both gone as well. Now, when you shift into gear the drive engages in a whisper smooth fashion and off you go.

Control Freaks

Yanmar has also stepped up and given their customers better controllability. The 8LV is electronically controlled, so a digital control station makes operation easy and precise. The benefits of this type of control station are two-fold. First, there are no more push-pull mechanical cable runs from the control to the engine which can rust and jam. With Can-Bus technology it’s a simple wire run and the control station is plug-and-play.

This also means that adding components or even another control station, as in the case of a tuna tower, or cockpit control station is as simple as adding another wire run. Additionally, you now have a whole host of features in those controls at no extra cost, such as engine sync, neutral throttle control, single lever command, and individual drive trim controls. These were expensive options in the not so distant past.

And since Yanmar has now refined how it talks to its engines, it is also easier for the engines to talk back to the operator with improved programmable displays. We can select from a series of displays to give us data on fuel consumption, MPG, temperatures, and pressure, among others. This data stream is compatible with large color displays showing such things as radar, depth, and even an engine room video.

With electronically controlled engines, it’s easy to decide what controls will be used, and where. In this instance, a sterndrive joystick is shown.

Digital controls provide the capability of synchronizing the engines with the touch of a button. Also single lever control, cruise mode, and individual trim adjustments are possible.

But What About Longevity?

The question has been raised by the die-hard old heavy diesel guys, “Can a light-weight diesel stand up?” That very question was posed to Yanmar and their response was, “We heard that concern 15 years ago with the introduction of the popular Yanmar 6LP. That engine has dominated the 300-hp class diesel range for over 10 years with a great track record for reliability and we even have customers with over 10,000 hrs on that engine."

The Yanmar spokesman went on the say, “Yanmar has had one standard test protocol for marine engines over the past 25 years. Every new model must pass the rigorous testing before the name goes on it. We don’t test the newest light-weight engines any differently than we did the older heavier mechanical engines.”

We look forward to testing this exciting new engine and comparing its performance to the gas engines it will replace. Keep an eye out.