General Aviation

SMA SR305-230
305 cubic inches (5 litres), 230 hp, 2,200 rpm, 12,500 ft ceiling (type certificate), air/oil cooled Jet A, A1 diesel, 4- cylinder, direct drive, direct injection, turbocharged, single lever control, 430 lb dry weight, 2,000 hr recommended TBO. (Formerly Renault- Moraine

SMA SR305-E Enhanced intercooled version
Same specs as -230, except 230 hp to 10,000 ft, ceiling raised to 20,000 ft, 460 lb dry weight

Centurion 2.01
21.5 cubic inches (1,991 cc), 135 hp (99 kW), specific fuel consumption 0.352 lb/hp-hr, dry weight 295 lb (134 kg) (Formerly Thielert)

Centurion 4.0
243.85 cubic inches (3,996 cc), 350 hp (257 kW), specific fuel consumption 0.350 lb/hp-hr, dry weight 600 lb (272 kg)

Photos by Tim Wheat
(crankshaft photo2 provided by Rotax)
Courtesy of Dean Vogel, Rotax Training, Lockwood Aviation, Sebring, FL

While this is a current-production engine, it is historic in the sense that it represents a significant shift in aircraft engine design. “…an aircraft engine designed by motorcycle engine engineers…” Its continuing popularity is a testament to its light weight, fuel economy and durability.

·   95 hp @ 5,500 crankshaft rpm, 100 hp @ 5,800 crankshaft rpm
·   (80 hp and turbocharged 115 hp FAR 33 versions are available)
·   Unleaded gasoline, 91 octane
·   82.6 cuin (1.352 L), 3.31” bore x 2.40” stroke
·   Pressed-together plain bearing crankshaft
·   Liquid-cooled heads with gear-driven water pump
·   Air-cooled cylinders with Gilnisil® nickel-silicon plating on aluminum bore with same expansion coefficient as pistons
·   Dry-sump lubrication with crankcase oil scavanged back to tank using engine blow-by pressure
·   Dual electronic self-energized ignition systems with electronic advance
·   Dual altitude-compensating constant-velocity carburetors with start enrichment circuit
·   Integrated 2.43:1 ratio reduction gear with cam type damper and optional overload clutch
·   Integrated 250 W alternator