Basic overview of Automobile (and motorbike) Engine Conversions for aircraft use
Many experimental airplanes fly successfully with “not – originally intended to fly” engines. This topic seems to divide pilots and aircraft homebuilders into two oposite groups, one loving and another hating auto conversion engines. This article will not try to advocate either of approaches however aims to provide the list of (usually) successful conversions.
There are included engines of various sizes in this list, starting from small, able to power single seat ultralight, to big engines able to power some more serious experimental airplanes.
Lets say among the most common engines proven by years of use could include following: VW, Corvair, Subaru, Suzukiand Honda. There are also good results in Europe with motorbike engines, such as from BMW 1100, 1150, 1200 and Suzuki. This is by no means a complete list...
VW - Volkswagen aircraft conversions
VWs are probably the most commonly converted engines in experimental aviation. I wont be copying a great source (even if little bit outdated now), so please read about VWs there: Aeroengine VW.
Corvair engine
Corvair is also quite popular in the US. Basically what you can get is approx. 90hp continuous direct drive, 6 cylinder, 4 stroke boxer engine. Read more on this Corvair overview or on “The Corvair Authority” website.
Honda aircraft conversions
Probably the best known are the products from Viking Aircraft Engines. They offer 100 – 110hp models based on the all aluminium, water cooled Honda engines.
Subaru conversions
Subaru engines are all alluminium, water cooled engines with PRSU. Subaru EA-81 (approx. 100hp) and EJ-22 (aprox. 160hp) are among those most popular. There exist also direct drive versions but the power output they generate is much lower. Read more on the website of Stratus 2000 Inc. company or in the Subaru engines overview. The company AirGearBoxcan be interesting to get reduction drives at reasonable costs for Subaru as well as for Suzuki, Honda, Toyota and BMW engines.
Suzuki conversions
Good sources of information about Suzuki conversions are: Raven Redrives and Airtrikes.net.
ACM Drahos – Europe based company offers well proven 100hp Suzuki 1.6L conversion with all – up weight of 87kg for approx. 5000 – 6000 USD (+- 5000 EUR). This model has several dozens flying for many years (more than a decade) presumably without problems.
BMW 1100 / 1150 / 1200
BMW motorbike engines can produce circa 70 – 100hp continuous. All people I know use BMW in their planes, have one from Take-Offcompany from Germany. Its a two-cylinder four-stroke engine with spur gear and centrifugal clutch. Acording to the manufacturers website, there are 3 models available [TAKE-OFF]:
- BOXER-flat engine R 1100 S, 72 kW at 7200 rpm/min, 61kg
- BOXER-flat engine R 1150 RS/RT, 70 kW at 7200 rpm/min, 61kg
- BOXER-flat engine R 1200 GS, 75 kW at 7200 rpm/min, 58kg
Suzuki motorcycle engines
I have seen some planes successfully flying with Vija Engines. The producer claims his models produce from 100 to 160hp. At the time of writing, there have been 4 models, all specs from [VIJA]:
VIJA J-10Si
4 stroke, 4 in line cylinders, 16 valves, Electronic fuel injection, 1186cc of displacement, 100 HP @ 6600 RPM, 235 N.m @ 4200 tr/min (propeller shaft measurement), Gear reductor, ratio of 2.55/1, Max. propeller speed: 2700 RPM, Multi-disks clutch in oil, Torque limiter by absorption included, Weight of 84kg ready to flight with exhaust and oil radiator.
VIJA AG-12Si
4 stroke, 4 in line cylinders, 16 valves, Electronic fuel injection, 1216cc of displacement, 120HP @ 7200 RPM, 270 N.m @ 4500 RPM, Gear reductor, ratio of 2.55/1, Max. propeller speed: 2860 RPM, Multi-disks clutch in oil, Torque limiter by absorption included, Weight of 84kg ready to flight with exhaust system and oil radiator.
VIJA J-16Ti (J-16T)
4 stroke, 4 in line cylinders, turbocharged, 16 valves, Electronic fuel injection, Displacement of 1186cc, 160 HP @ 7000 RPM, 310 N.m @ 5500 RPM, Mechanical reductor, ratio of 2.55/1, Max. propeller speed 2800 RPM, Multi-disks clutch strengthened in engine oil, Torque limiter by absorption included, Weight of 88kg, ready to flight with Turbo, exhaust system and oil radiator.
VIJA J-10Sbi / AG-12Sbi
4 stroke, 4 in line cylinders, 16 valves, Electronic fuel injection, 1186cc / 1216cc, 100HP / 120HP, 235 N.m / 270 N.m, Mechanical reductor, ratio of 2.55/1, Max. propeller speed 2800 RPM, Multi-disks clutch strengthened in engine oil, Torque limiter by absorption included, Weight of 79kg ready to flight with exhaust and oil radiator.
