Yanmar - Zeus Pod Drive System Offered by Yanmar

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Captain's Report

ZF Pod Drive by Yanmar

By Capt. Rob Smith During 2008,

I have been testing several new and improved engines from Yanmar Marine. Yanmar doesn’t rush to meet the competition or one-up the competition, they study, and design and test products until they are sure of what they say it will do. That’s what they did with the Zeus Pod Drive System. This system is designed to be used with Yanmar diesel marine engines from 400-530mph. That means the 6LY3 Series and the new 6CX530 are well suited for duty. The Zeus pod drive system is joystick operated at low speed around the docks and other tight maneuvering situations and continues to offer advantages at cruising and top speed. The Zeus system operates with two independently operated drives which are computer controlled through inputs from the joystick.

Coupled with Yanmar’s lightweight, compact diesel engines, the system significantly reduces weight and space taken up by the engine and marine gear. This space can be used by the builder in a multitude of ways such as expanding the interior space, lowering the cockpit or just having more room in the engine spaces for routine maintenance. At this point, there aren’t plans to use this system in re-power situations as it does require specific stringer and weight distribution considerations that are difficult to do in re-power situations.

The drives are mounted in pockets which mean the drives are protected first by the keel of the boat, then by the design of the drive. Any debris that comes in contact with the drive will likely be deflected by the bullet and leading edge of the gearcase and skeg. The drives are designed to shear away in case of catastrophic contact without leaving a gaping hole that sinks your boat and ruins your day.

The Zeus system utilizes twin counter-rotating props in an aft facing design. This more traditional design not only will be better accepted, but offers additional performance benefits. We the pod drive system, forward thrust is immediate rather than having to “push” as in forward facing designs. Also, the Zeus Pod Drive starts from horizontal rather than a down angle as in inboard systems, therefore delivering thrust immediately forward rather than down until the bow returns to horizontal and/or on plane. The trim tab is integrated into the drive unit, so you don’t have a separate system to install or maintain.

The drive is mated to the hull with two large rubber grommets that seal the water out and significantly reduce noise and vibration. Within the hull, Yanmar runs the wiring harness through an intermediate “black box” then to the Zeus Pod Drive where it delivers the proper “language” for inputs to the on-board computer. One of the only things I saw that involve maintenance that you might do is the filter for the hydraulic fluids on the port side of the drive. The system is protected for electrolysis with a large zinc plate on the trim tab and a Mercathode system.

The exhaust is routed from the engine through the drive via a large connection on the port side of the drive. Yanmar T’s off another 2” bypass line which they claim reduces the rumble often observed with underwater exhaust systems on boats in the slip. Toward the front of the drive on the port side is a raw water ball valve to bring cooling water in to the engine and the drive system where it cools the hydraulic fluid through a heat exchanger on board the drive.

Yanmar is already working with one of its builder partners to install the first units on a Luhr’s which should be ready for the Miami International Boat Show in February 2009. That will be one of the first opportunities for you to try out the joy of joystick drives and the fun of a Yanmar Diesel Marine Engine with the Zeus Pod Drive.