Mercury Racing, headquartered in Fond du Lac, Wisconsin, has released a new stealth outboard for the United States government, the OptiMax Diesel. Developed for the US Department of Defense, the exclusive spark-ignited, direct fuel-injected two-stroke runs widely accessible ultra-low-sulfur diesel fuel.
"A Navy ship crash in 1995, which resulted in an explosive gasoline fire, spawned a DoD directive for all gasoline-powered engines and gasoline fuel tanks be removed from Naval ships by 2010,' said Tony Nahitchevansky, Mercury Marine government accounts manager.
The mandate called for engines to be developed to operate on fuels that are: able to improve ship safety by minimizing fire hazards; more economical and efficient; and readily available as single battle space fuel.
Mercury Racing's 3.0 Liter V-6 Diesel, which produces 175 propshaft horsepower, shares 95 percent of its components with the gasoline engine from which it is derived. Additionally, Mercury says the engine only has a handful of unique parts, requiring minimal additional training for maintenance.
The company says the engine's two-stage, direct-injection system uses a small charge of compressed air to finely atomize the diesel fuel as it injects into the combustion chamber. Atomizing the fuel into a fine mist allows for ignition via spark to occur, while delivering enhanced high rpm running quality. A glow plug works in concert with the spark plug for improved cold weather starting and idle quality. An on-board Propulsion Control Module (PCM) microprocessor optimizes fuel and spark timing for improved running quality and performance throughout the engine's operating range. SmartCraft Engine Guardian provides real-time, self-protection engine fault diagnostics and messaging.
The engine's 3.0-liter powerhead, customized with a unique cylinder head designed specifically for combustion of diesel fuel, is matched with high-performance cylinder liners for optimal horsepower and engine running quality.
The OptiMax Diesel features stealthy, tone-on-tone graphics that feature the new Mercury Racing word mark – similar to those featured on the new Racing Verado 400R consumer performance outboard models. Mercury Racing OptiMax Diesel outboards are available with a 25-inch (635 mm) center section and the 2:1 Fleet Master gearcase in both right-hand and left-hand rotation.
The Mercury Racing's 3.0 Liter V-6 Diesel outboard is a government-only engine. Currently the outboard is undergoing final validation testing by the US Department of Defense. Pending approval, the engines are expected to start being delivered for late Q3 or Q4 of this year.