With fuel prices climbing, the Martins wanted to power their new boat with a fuel-efficient diesel without compromising the boat’s perform-
ance. They chose the Yanmar 6LPA-STP2, an in-line, turbo-charged and intercooled, direct-injection diesel rated at 315-hp at 3800 rpm. Weighing in at just under 900 pounds (without transmission) the engine's combination of high revving, light weight and excellent fuel efficiency hits the nail on the head for a single-screw center-console. After speaking with Bob Schroer, at Mack Boring, the Northeast and mid-Atlantic regions’ distributor for Yanmar engines, I learned that the 6LP has been a popular choice for repowering boats—especially ones fitted with 454 V-8s. Such a repower often significantly improves both performance and fuel economy.
The 6LP is also a time-tested engine, developed in the mid 1990s by Yanmar in cooperation with Toyota. In fact, the non-marine version of the engine was used in the Toyota Land Cruiser (popular overseas, but never exported to North America). Since the 6LP is equipped with mechanical fuel injection, it is still possible for skilled owners to service the high pressure fuel system or pull injectors without needing a technician.
The shaft and propeller are set in a tunnel to keep the draft to a minimum. The 19-inch four-bladed Acme prop is tuned with a deep cup. Our test boat was equipped with a ZF63A hydraulic transmission. Composite chose a 1.56:1 reduction for this hull, which keeps the prop turning faster than a 2:1 gear ratio. This was done with an eye toward maintaining her top end performance, and it seems to have paid off—at wide open throttle, the Composite 26 reached 32 knots with three people aboard. At a cruising rpm of 3000, she turned out 25 knots. According to Yanmar’s test figures, the 6LP burns just under 8 gallons per hour at this speed. Pretty sweet compared to outboards!
The 26 gave us a smooth ride. The combination of 24-degree deadrise aft and the dramatic Carolina-style bow flare means that this boat was built for big water. The center-console is offered with a variety of power options, from a single or twin outboard to single-screw inboard gas or diesel engines. Our test boat was Hull #0 (the original plug-boat from which a mold was taken to build future hulls) and is about 800 pounds heavier than Hull #1, which has already been delivered to its new owner in Florida.