Cummins MerCruiser Dieselís QSC 8.3 Marine Cummins MerCruiser Dieselís QSC 8.3 builds horsepower the old fashioned way, with a wastegated turbocharger, a 24-valve cylinder head and a highly efficient aftercooler. All these traditional components build torque from low rpm all the way up to wide-open throttle. Translation: strong acceleration, and especially strong for a diesel.On the other hand, Cummins MerCruiser Diesel also builds horsepower with cutting edge technology, namely a state of the art, high-pressure, common rail fuel system. For those few souls who may be unfamiliar with the species, common rail is renowned all around the world for the way it improves fuel economy and reduces idle noise at the same time it virtually eliminates exhaust smoke and odor. In short, common rail has civilized the diesel engine. The good news gets better. All new Cummins Diesel Quantum Series engines communicate with the helm station via MerCruiser SmartCraft. Besides monitoring raw performance, SmartCraft also performs onboard diagnostics at the same time itís busy monitoring fuel tank levels, the GPS, rudder angle, water depth and temperature. This boatload of information can be viewed at the helm on either CMD's new Diesel View digital display, or from digitally-driven analog gauges. Beyond pure performance, the real eyebrow raiser here is the build list of the QSC components. Special alloy pistons are oil gallery-cooled for longer life. The cylinder head is machined from a high temperature alloy for extra toughness. The block has been reinforced to better handle extreme combustion pressure. Intake and exhaust valves and seats are special alloys for longer life. The engine control module (ECM) is cooled by fuel flow to protect it against overheating. A water-in-the-fuel sensor talks directly to the engine management system, the same system that warns should engine coolant run low or begin to boil. Stainless steel tubing has replaced rubber hoses, and along with O-ring seals, minimizes, if not eradicates, nagging seawater leaks. For the same reason, hose clamps have been banished. All these things add up to extreme reliability and longevity. Finally, the Cummins Diesel QSC8.3 series is fully compliant with the stringent US EPA mandates. In addition to EPA Tier 2 recreational and commercial compliance, the engine is IMO certified. Cummins MerCruiser Diesel QSC8.3 Rated 540 Horsepower is part of the Quantum Series.