916 iS aircraft combustion engine

The Rotax 916 iS is a turbocharged, four-cylinder, four-stroke aircraft piston engine from Rotax (BRP-Rotax), rated at 160 hp (117 kW). It is a liquid- and air-cooled aircraft combustion engine with redundant electronic fuel injection and ignition, an intercooler and a propeller speed reduction gearbox, and it is offered for aircraft that need a high power-to-weight ratio from a compact installation.

The maximum power is 117 kW (160 hp) at 5800 rpm, with a torque of 193 Nm at that speed. The maximum continuous power is 101 kW (137 hp) at 5500 rpm, with 175 Nm. The displacement is 1352 cm³, from a bore of 84.0 mm and a stroke of 61.0 mm. The turbocharger keeps the engine at full take-off power up to 15,000 feet, and the maximum operating altitude is 23,000 feet. The maker rates the time between overhauls at 2,000 hours. For an integrator, the difference between the take-off rating and the continuous rating is the key figure for mission planning, because cruise power has to be taken from the 101 kW rating.

The engine with its reduction gearbox (ratio 2.54, with overload clutch), turbocharger, intercooler and exhaust system weighs 85.8 kg. The engine suspension frame (2.0 kg), the external alternator (3.0 kg) and the air guide baffle (0.4 kg) are listed separately. Lubrication is by a dry-sump forced system with a separate oil tank and hydraulic valve tappets. An engine management system controls the fuel injection and ignition, with an eco mode available. The electric starter is available for 12 V or 24 V systems. The engine runs on fuel with a minimum of MON 85 or RON 95 (AKI 91), which includes leaded and unleaded fuel, AVGAS 100LL and ethanol 10 blends.

The maker lists variants that differ in their approval basis. The iS versions are compliant with ASTM standards, and the iSc versions are certified according to EASA CS-E. Engine performance varies with ambient conditions, temperature and altitude.

Typical applications are fixed-wing and rotary aircraft in light aviation that need an engine in the 160 hp class with fuel injection and a turbocharger. A configurator on the maker's site is used to set up the engine for a given installation.