Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.
Issue link: http://experimenter.epubxp.com/i/271000
EAA Experimenter 37 Aeropower engines now feature a new and narrower propel- ler reduction unit that allows for much more streamlined engine cowlings. Props are rotating counterclockwise (clock- wise on the 95-hp version), and the electrohydraulic prop governor is an option. In case that the market demands a geared engine with clockwise prop rotation (for twin-engine installation), MW Fly could satisfy that request in the future. The B22/25 Aeropower engines feature a unique mechan- ical torque reduction system called ADC. According to MW Fly, this electrohydraulic system replaces the commonly used mechanical torque reduction that is a critical mechani- cal component and is subject to wear. The ADC system is lowering engine vibrations during the start procedure, dur- ing engine shutdown (it prevents the kickback), and on low engine rpm. What in theory sounds complicated can simply be explained like this: The engine computer is lowering the engine compression below 1,900 or 2,000 engine rpm, lifting the exhaust valve a bit so that the engine compression drops from the normal 1:10-to-1:5 ratio. The consequence is that the engine is firing much "smoother" than running with the "full compression. The ADC system doesn't need any main- tenance and has been designed so that any failure of hydrau- lics or electronics does not compromise the flight safety as the engine can be continuously operated in that mode (with a 25 percent lower power output). The MW Fly engines have been tested in fixed-wing aircraft, gyrocopters, trikes, and most recently a helicopter. After years of development, the company can confirm its original calculations and expectations now. Recently, the European Aviation Safety Agency (EASA) 50-hour test for certification was completed, so ASTM certification is ex- pected soon. The MW Fly B22/25 engines have definitively enriched the engine choices for the experimental/ light-sport aircraft builder. For more information, visit www.MWfly.it and www.David.it . The North American distributor's address for these engines is Ottawa Aviation Services, 220 Hunt Club Road, Ottawa, Ontario, K1V 1C1, Canada. Visit www.OttawaAviationServices.com . Marino Boric, EAA 1069644, is an aeronautical engineer and holds a private pilot license in Germany with commercial and instrument rat- ings (CPL/IFR). He also fl ew as a military pilot. So-called "gravity" valves are installed between the crankcase and the oil sump and let the oil f ow from the crankcase to the oil sump, but they stop the f ow in the opposite direction in case of an inverted f ight. Photography courtesy Marino Boric Two of the four monolithic (one-piece) connecting rods on the MW Fly engines. MW Fly owners Stefano Marella and Guido Fantini discuss the 150-hp engine details with the owner of Offi cine Aeronautiche David (OAD) in Brescia, Italy, where the engine is assembled. The bigger bore cylinder liner and the piston for the 150-hp engine. E A A E X P _ M a r 1 4 . i n d d 3 7 EAAEXP_Mar14.indd 37 3 / 3 / 1 4 1 0 : 3 4 A M 3/3/14 10:34 AM