Rotax on July 21 introduced its most powerful engine yet—the 135-horsepower 915 iS. The maximum continuous power rating is 127 hp. Rotax said the 915 iS has the best power-to-weight ratio in its class, and could maintain full takeoff power to at least 15,000 feet. Service ceiling is posted as 23,000 feet.
The engine was developed at the specific request of Rotax customers, according to Thomas Uhr, vice president and general manager of BRP-Powertrain. There is market demand for a more powerful engine that will allow higher payloads and shorter takeoffs, and the new four-stroke, four-cylinder, turbocharged, intercooled and fuel-injected engine is being designed to fill that niche.
The 185.2-pound engine produces maximum power at 5,800 rpm, and comes with a propeller reduction gearbox, electric starter, dual generators, and a dry sump lubrication system with a separate oil tank. Exhaust gas temperature sensors are integrated into the turbochargers. The crankcase is of the same design used in Rotax’s 912 iS, but the 915 iS’ crankshaft is heavier. A dual-channel engine control unit (ECU) manufactured by Rockwell Collins provides fault detection and diagnostic functions, as well as knock sensing and overboost protection. TBO is projected at 2,000 hours.
Production of the 915 iS is scheduled to begin in the second of half of 2017.