Vokswagen automobiles have been built by Volkswgen AG of Wolfsburg, Germany since about 1946. Development began earlier (for historical references, see here or here). All VW auto engines before the mid-1970's had four cylinders, were air-cooled and horizontally-opposed. Production of the air-cooled engine versions continued in many parts of the world subsequently, but the principal models, beginning with the Rabbit and Golf had four-cylinder, inline, liquid-cooled engines. Volkswagen air-cooled, horizontally-opposed, four-cylinder automobile engines have been converted for aircraft use almost since VW production began.
It must be borne in mind that Volkswagen does not authorize the use of VW engines or parts by any company, nor do they represent or warrant that their engines are suitable for use in aircraft of any kind. Any company modifying VW auto engines for aircraft use is not affiliated in any way with Volkswagen. This is the policy by most of the auto manufacturers whose engines have been adapted and converted for aircraft use. In the experimental aircraft community, these engines are generally classified as "Alternative Engines". Everyone dealing with them must appreciate that they are classified as experimental when they are not type certificated by the governing national authority. No VW conversions have been type certificated in the US, but some have been certificated in their own countries. An issue that must be considered, then, is the performance and weight data, which probably have been provided by the conversion firm itself. The bore, stroke and displacement data have been provided in the same way.
Websites for what are called "Alternative Engines"; i.e., those based on automobile, motorcycle, marine engines, etc. (and not designed specifically as aircraft engines), are listed here. VW engines are among those considered. Moreover, specific Websites may be found by use of search engines; e.g., Google and Yahoo. Articles on various aspects of Alternative Engines can be found in KP1/00, 2/00, 8/01, and 9/01.
Mike Kraus' Homebuilt Homepage, under "Vendors".
Ron Wantajja's Sea and Sky Aviation Page.
Jake Crause's Homebuilt Airplanes Website.
Eric Ulmer's Homebuilt Aircraft Engine Directory.
VW engines were converted, initially, for use in homebuilt, experimental, non type-certificated light aircraft by individuals or very small firms. The compiler does not intend to engage in speculation about the identity of the first VW converters, which were prior to 1950. One of these is Guido Visentini (Italy), who is mentioned in the later section for converters that do not have their own page. Certainly, some of the earliest successful proponents of VW conversions were the French homebuilders of very light, single-seat aircraft. Edouard Joly and Jean Delemontez used converted early-production VW's, along with many other small engines, for their Jodel D.9 Bébé as did Roger Druine for his Druine D.3 Turbulent.
Stock VW engines provide an adequate power-to-weight ratio so that direct drive is feasible in many applications. Thus, most VW conversions use direct drive of the propeller and thus avoid the reduction of propeller rpm from that of crankshaft rpm; i.e., they do not make use of Redrives, or as they are called in this compilation, Propeller Speed Reduction Units (PSRU). Some converters, from the earliest days to the present, do use PSRU's and a separate section below discusses those that have been notable and are presently available. There are three basic types of PSRU's; mechanical gearboxes, chain-drive to an offset shaft, and belt-drive to an offset shaft. All achieve propeller rpm suitable for obtaining maximum power with efficient propellers that have tip speeds low enough to avoid excessive noise and degradation of efficiency. In this Compilation, "reduction", "redrive" and "PSRU" are used interchangeably with "gearing", independent of the means of reduction; i.e., "geared to 0.549" simply means that the prop rpm is 0.549 of the engine rpm, but not necessarily by mechanical gears.
As VW engines grew in displacement and power, they were used for larger aircraft than those originally VW-powered. Homebuilders, mostly in the US, realized that 1/2 of a larger-displacement, newer-production VW engine would provide a respectable power-to-weight ratio, just as the early four-cylinder VW engines had in Europe and, then, in the rest of the World. Again, the compiler does not intend to engage in speculation about the identity of the first 1/2 VW converters, but such engines were running in the 1970's. Then, the FAA introduced Part 103 into the Federal Aviation Regulations for US ultralight aircraft in 1982. These regulations require a maximum empty aircraft weight of only 254#, so 1/2 VW conversions became viable and have continued to flourish.
Along with the development of new engine versions by VW, a huge aftermarket demand for VW parts was recognized early by manufacturers throughout the world. Many of these manufacturers have used various VW engine models and component parts as the basis for their own performance enhancement efforts. Many of these automotive enhancements have made their way into conversions of VW engines for aircraft. Moreover, complete "VW" engines can be built entirely from aftermarket parts.
There are four types of air-cooled, four-cylinder VW engines. All Type 1 engines and those Type 2 engines of 1600cc displacement or less (before 1973) are configured such that their cooling fan is driven from the generator shaft, which is above the centerline of the crankshaft. These are called "Upright Fan Engines". Those Type 2 engines of 1700cc or greater (1973 and later) and all Type 3 and Type 4 engines have cooling fans driven directly by the crankshaft. These are called "Suitcase Engines" because of their compact configuration.
Type 1 engines are used in Beetles, Super Beetles, Karmann Ghias, and Beetle Convertibles.
Type 2 engines are used in Vans, Buses, Campers, Kombis, and Vanagons.
Type 3 engines are used in in Model 3 Fastbacks and Squarebacks.
Type 4 engines are used in in Models 411 and 412 Two-Doors, Four-Doors and Wagons.
This information and much other information about VW engines and their maintenance and overhaul can be found in Volkswagen Auto Engine Reference Books, especially:
Chilton "VW Air-Cooled 1949-1969 Repair Manual"
Chilton "Auto Repair Manual 1964-1971"
Chilton "VW 1970-1981 Repair & Tune-Up Guide"
The development of newer, larger displacement engines by VW themselves and the availability of "VW" parts from aftermarket manufacturers for all VW designs have been discussed above. This has led to an almost bewildering number of bore and stroke combinations of converted VW aircraft engines, as can be seen below in the listing of engine displacements. Of the many versions of VW engines, the following are known to have been converted to aircraft use. The format will be to list all of the individual engine designs first, with notes about their previous auto usage, where available. Then the firms that now are or formerly had been converting that individual engine design for aircraft propulsion and which have a separate page in this Compilation will be listed. Finally, known Applications, for which the identity of the converter has not been specified, are given. These applications come from various Websites (including aerofiles.com), "Jane's All the World's Aircraft", "Kitplanes" magazine and the EAA's "Sport Aviation" and "Sport Pilot & Light Sport Aircraft" (formerly "Experimenter") magazines. These sources do not always identify a conversion person or firm.
The horsepower rating listed below for each engine design (after the VW cc value) has been estimated by the compiler after plotting the horsepower vs. displacement data from the engines built by all of the conversion companies. These data are for normally-aspirated, direct-drive VW engine conversions running at about 3400 rpm or below so that an efficient propeller can be used. They are no longer applicable if a turbocharger, a PSRU, or significantly higher rpm is used. A reasonable straight-line approximation is given by the equation:
Horsepower ~ Displacement (in cc), divided by 30,
where in our usage here, ~ denotes "approximately equal to" . This approximate horsepower, except for the full VW engines of less than 1300cc, is such that almost all performance data points are within -10% to +10% of the approximate value for both full VW and 1/2 VW engines. As an example, the power (rounded off to the nearest integer) of an O-97, VW "1600" cc is ~ 1585/30, which is ~ 53 hp. The data points of the various O-97 conversions are between ~ 48hp and ~ 58hp.
O-69 - - {2.953 / 2.520 / 69.0} / {75 / 64 / 1131}
Same stroke as O-73, O-79, O-99.
VW 1131 cc ( ~ 26hp) Beetle models from 1946 to 1953.
Converters: Ardem, Druine (France).
Applications: (France) Druine D.31 Turbulent; Fournier R.F.01 motorglider; Gatard Stratoplan 02 Poussin; Jodel D.92 Bébé; Pierre Morin 01. (Hungary) Motor-Pilis. (Indonesia) Nurtanio NU-25 Kunang.
O-73 - - {3.031 / 2.520 / 72.7} / {77 / 64 / 1192}
Same bore as O-78.
Same stroke as O-69, O-79, O-99.
VW "1200 cc" ( ~ 32hp) Beetle models from 1953 to 1965.
Converters: Ardem, Druine (France); Rectimo (France); Rollason (UK).
Applications: (France) Gatard Stratoplan 02 Poussin; Nicollier HN-433 Menestral. (Germany) Pützer Motorraab. (Indonesia) Nurtanio Kunang Model 35. (Japan) JEAA Makino MHO.235 biplane. (UK) Brookland Mosquito Mk.1, Mk.2 gyroplanes.
O-78 - - {3.031 / 2.717 / 78.4} / {77 / 69 / 1285}
Same bore as O-73.
Same stroke as O-91, O-96, O-97, O-102, O-107, O-108, O-112, O-117.
VW "1300 cc" ( ~ 42hp) Beetle models from 1965 to 1967.
Converters: Rollason (UK); Monnett (US).
Applications: (France) Besneux P.70B; Gatard Stratoplan AG 05 Mésange; Nicollier HN-433 Menestral; Survol-Fauvel AV. 50, 61. (Indonesia) Nurtanio Super Kunang Model 40. (UK) Livesey D.L.5; Sizer Sapphire.
O-79 - - {3.150 / 2.520 / 78.5} / {80 / 64 / 1287}
Same stroke as O-69, O-73, O-99.
VW 1287 cc ( ~ 42hp).
Converters: Pollmann, HEPU, KFM (Germany); Ital-American, IAME, KFM (Italy).
O-91 - - {3.268 / 2.717 / 91.2} / {83 / 69 / 1493}
Same stroke as O-78, O-96, O-97, O-102, O-107, O-108, O-112, O-117.
VW "1500 cc" ( ~ 50hp) Beetle models from 1967 to 1969.
Converters: Clutton (UK); Rollason (UK).
Applications: (France) Besneux P.70B [F-PVOG]; Croses EAC-3 Pouplame; Pottier P.70S. (Japan) JEAA Terno Kago TF-1. (Switzerland) Berger-Erla (rebuilt German pre-WWII Erla monoplane). (UK) Livesey D.L.5.
O-96 - - {3.346 / 2.717 / 95.6} / {85 / 69 / 1566}
Same stroke as O-78, O-91, O-97, O-102, O-107, O-108, O-112, O-117.
VW 1556 cc ( ~ 52hp).
Converters: None found; see 1/2 VW O-48.
O-97 - - {3.366 / 2.717 / 96.7} / {85.5 / 69 / 1585}
Same stroke as O-78, O-91, O-96, O-102, O-107, O-108, O-112, O-117.
VW "1600 cc" ( ~ 53hp) Beetle models from 1969.
Converters: Westermayer (Austria); Aeroálcool (Brazil); Rectimo (France); Rollason (UK); Great Plains (US); HAPI (US); Mekker (US); Monnett (US); Preceptor (US); Revmaster (US).
Applications: (Canada) Zenair Mono-Zénith. (Finland) Terramäki-Eerola ATE-3 gyroplane. (Switzerland) Brügger MB-2 Colibri 2. (UK) Campbell Cricket [G-AYRC] gyroplane; Ekin Airbuggy gyroplane; Livesey D.L.5; McCandless (later revised by WHE firm) M-4 gyroplane. (US) Hummel Ultra Cruiser Plus.
O-99 - - {3.543 / 2.520 / 99.4} / {90 / 64 / 1629}
Same bore as O-107, O-111, O-115, O-121, O-130.
Same stroke as O-69, O-73, O-79.
VW 1629 cc ( ~ 54hp).
Converters: Ital-American, IAME, KFM (Italy).
O-102 - - {3.465 / 2.717 / 102.4} / {88 / 69 / 1679}
Same bore as O-110.
Same stroke as O-78, O-91, O-96, O-97, O-107, O-108, O-112, O-117.
VW 1679 cc ( ~ 56hp).
Converters: Limbach (Germany); Great Plains (US); HAPI (US); Monnett (US).
O-107 - - {3.543 / 2.717 / 107.1} / {90 / 69 / 1756}
Same bore as O-99, O-111, O-115, O-121, O-130.
Same stroke as O-78, O-91, O-96, O-97, O-102, O-108, O-112, O-117.
VW 1756 cc ( ~ 59hp).
Converters: Limbach (Germany); Sauer (Germany).
O-108 - - {3.563 / 2.717 / 108.3} / {90.5 / 69 / 1775}
Same bore as O-122*.
Same stroke as O-78, O-91, O-96, O-97, O-102, O-107, O-112, O-117.
VW 1775 cc ( ~ 59hp).
Converters: Aeropower (Australia); VW Engine Centre (Australia).
O-110 - - {3.465 / 2.913 / 109.9} / {88 / 74 / 1800}
Same bore as O-102.
Same stroke as O-115.
VW 1800 cc ( ~ 60hp).
Converters: Limbach (Germany).
O-111 - - {3.543 / 2.835 / 111.8} / {90 / 72 / 1832}
Same bore as O-99, O-107, O-115, O-121, O-130.
VW 1832 cc ( ~ 61hp).
Converters: Ital-American, IAME, KFM (Italy).
O-112 - - {3.622 / 2.717 / 112.0} / {92 / 69 / 1835}
Same bore as O-127, O-133, O-140.
Same stroke as O-78, O-91, O-96, O-97, O-102, O-107, O-108, O-117.
VW 1835 cc ( ~ 62hp).
Converters: Aeropower (Australia); Great Plains (US); HAPI (US); Hummel (US); Monnett (US); Preceptor (US); Revmaster (US); Torque Master (US).
O-115 - - {3.543 / 2.913 / 114.9} / {90 / 74 / 1883}
Same bore as O-99, O-107, O-111, O-121, O-130.
Same stroke as O-110.
VW 1883 cc ( ~ 63hp).
Converters: Limbach (Germany).
O-117 - - {3.701 / 2.717 / 116.9} / {94 / 69 / 1915}
Same bore as O-120, O-132, O-139, O-152.
Same stroke as O-78, O-91, O-96, O-97, O-102, O-107, O-108, O-112.
VW 1915 cc ( ~ 64hp).
Converters: Great Plains (US); HAPI (US); Torque Master (US); Valley Engineering (US).
O-120 - - {3.701 / 2.795 / 120.3} / {94 / 71 / 1971}
Same bore as O-117, O-132, O-139, O-152.
Same stroke as O-131, O-144.
VW 1971 cc ( ~ 66hp).
Converters: Limbach (Germany).
O-121 - - {3.543 / 3.087 / 121.7} / {90 / 78.4 / 1995}
Same bore as O-99, O-107, O-111, O-115, O-130.
Same stroke as O-123.
VW 1995 cc ( ~ 66hp).
Converters: Limbach (Germany).
O-122* - - {3.563 / 3.071 / 122.5} / {90.5 / 78 / 2007}
Same bore as O-108.
Same stroke as O-127, O-132.
VW 2007 cc ( ~ 67hp).
Converters: Monnett (US).
O-122** - - {3.874 / 2.598 / 122.5} / {98.4 / 66 / 2008}
Same bore as O-131, O-143.
VW 2008 cc ( ~ 67hp).
Converters: Aeropower (Australia); VW Engine Centre (Australia).
O-123 - - {3.559 / 3.087 / 122.8} / {90.4 / 78.4 / 2013}
Same stroke as O-121.
VW 2013 cc ( ~ 67hp).
Converters: IMAER, Retimotor (Brazil).
O-125 - - {3.366 / 2.968 / 125.0} / {93 / 75.4 / 2049}
Same bore as O-153.
VW 2049 cc ( ~ 68hp).
Converters: JPX (France).
O-127 - - {3.622 / 3.071 / 126.6} / {92 / 78 / 2074}
Same bore as O-112, O-133, O-140.
Same stroke as O-122*, O-132.
VW 2074 cc ( ~ 69hp).
Converters: Aeropower (Australia); Great Plains (US); Hummel (US); Preceptor (US); Revmaster (US).
O-130 - - {3.543 / 3.307 / 130.4} / {90 / 84 / 2138}
Same bore as O-99, O-107, O-111, O-115, O-121.
Same stroke as O-151.
VW 2138 cc ( ~ 71hp).
Converters: Sauer (Germany).
O-131 - - {3.874 / 2.795 / 131.8} / {98.4 / 71 / 2160}
Same bore as O-122**, O-143.
Same stroke as O-120, O-144.
VW 2160 cc ( ~ 72hp).
Converters: VW Engine Centre (Australia).
O-132 - - {3.701 / 3.071 / 132.1} / {94 / 78 / 2165}
Same bore as O-117, O-120, O-139, O-152.
Same stroke as O-122*, O-127.
VW 2165 cc ( ~ 72hp).
Converters: HAPI (US).
O-133 - - {3.622 / 3.228 / 133.1} / {92 / 82 / 2180}
Same bore as O-112, O-127, O-140.
Same stroke as O-139, O-142, O-148.
VW 2180 cc ( ~ 73hp).
Converters: AeroVee (US); Great Plains (US); Monnett (US); Preceptor (US); Torque Master (US).
O-134 - - {3.740 / 3.031 / 133.2} / {95 / 77 / 2183}
Same bore as O-142.
Same stroke as O-143.
VW 2183 cc ( ~ 73hp).
Converters: AeroPrag (Czech Republic).
O-139 - - {3.701 / 3.228 / 138.9} / {94 / 82 / 2276}
Same bore as O-117, O-120, O-132, O-152.
Same stroke as O-133, O-142, O-148.
VW 2276 cc ( ~ 76hp).
Converters: Able (US); Great Plains (US); Valley Engineering (US).
O-140 - - {3.622 / 3.386 / 139.6} / {92 / 86 / 2287}
Same bore as O-112, O-127, O-133.
VW 2287 cc ( ~ 76hp).
Converters: Hummel (US).
O-142 - - {3.740 / 3.228 / 141.9} / {95 / 82 / 2325}
Same bore as O-134.
Same stroke as O-133, O-139, O-148.
VW 2325 cc ( ~ 78hp).
Converters: JPX (France).
O-143 - - {3.874 / 3.031 / 142.9} / {98.4 / 77 / 2342}
Same bore as O-122**, O-131.
Same stroke as O-134.
VW 2342 cc ( ~ 78hp).
Converters: VW Engine Centre (Australia).
O-144 - - {4.055 / 2.795 / 144.4} / {103 / 71 / 2366}
Same bore as O-160.
Same stroke as O-120, O-131.
VW 2366 cc ( ~ 79hp).
Converter: Limbach (Germany); Great Plains (US).
O-148 - - {3.819 / 3.228 / 147.9} / {97 / 82 / 2424}
Same bore as O-151, O-162.
Same stroke as O-133, O-139, O-142.
VW 2424 cc ( ~ 81hp).
Converters: Limbach (Germany).
O-151 - - {3.819 / 3.307 / 151.5} / {97 / 84 / 2483}
Same bore as O-148, O-162.
Same stroke as O-130.
VW 2483 cc ( ~ 83hp).
Converters: Sauer (Germany).
O-152 - - {3.701 / 3.543 / 152.5} / {94 / 90 / 2498}
Same bore as O-117, O-120, O-132, O-139.
Same stroke as O-162, O-181.
VW 2498 cc ( ~ 83hp).
Converters: Able (US).
O-153 - - {3.661 / 3.622 / 152.6} / {93 / 92 / 2500}
Same bore as O-125.
VW 2500 cc ( ~ 83hp).
Converters: Mudry (France).
O-160 - - {4.055 / 3.091 / 159.7} / {103 / 78.5 / 2616}
Same bore as O-144.
VW 2616 cc ( ~ 87hp).
Converters: Limbach (Germany).
O-162 - - {3.819 / 3.543 / 162.3} / {97 / 90 / 2660}
Same bore as O-148, O-151.
Same stroke as O-152, O-181.
VW 2660 cc ( ~ 89hp).
Converters: Sauer (Germany).
O-181 - - {4.030 / 3.543 / 180.8} / {102.36 / 90 / 2962}
Same stroke as O-152, O-162.
VW 2962 cc ( ~ 99hp).
Converters: Revmaster (US).
Firms known to have offered full Volkswagen conversions for aircraft, now or in the past, and which have a separate page in this Compilation, are:
Able Experimental Aircraft Engine Co. (US) without a Website.
Aeroálcool Tecnologia LTDA (Brazil) with their Aeroálcool Website.
AeroConversions [AeroVee] , Inc. (US) with their AeroConversions Website.
Aeropower Engines, Pty. Ltd (Australia) with their Aeropower Website.
AeroPrag (Czech Republic), Tatra (Czechslovakia) with the AeroPrag Website in the Czech language and the Tatra Auto Club of Slovakia Website.
Avions Roger Druine [Ardem] (France) without a Website.
Eric Clutton (UK) with Eric Clutton's Website.
Great Plains Aircraft Supply Co. (US) with their Great Plains Website.
Grob Aerospace (Germany) without a Website.
Homebuilt Aircraft Products, Inc. [HAPI] (US) without a Website.
Hummel Engines (US) with their Hummel Engines Website and the Hummel Aviation Website.
Industria Mecânica E Aeronáutica LTDA [IMAER], Retimotor (Brazil) without a Website.
Ital-American Motor Engineering [IAME], KFM (Italy) without a Website.
JPX (France) with their JPX Website.
Limbach Flugmotorenbau (Germany) with their Limbach Website.
William J. Mekker (US) without a Website.
Monnett Experimental Aircraft (US) without a Website.
Avions Mudry (France) without a Website.
Pieper Motorenbau GmbH [STAMO] (Germany) without a Website.
Heinz Pollmann Fahrzeug-Motoren-und Flugmotorenbau, HEPU, KFM (Germany) without a Website.
Preceptor (US) with their Preceptor Website.
Rectimo Aviation SA (France) without a Website.
Revmaster Aviation (US) with their Revmaster Aviation Website.
Rollason Aircraft and Engines Ltd (UK) without a Website.
Sauer Motorenbau (Germany) with their Sauer Website.
Stark Flugzeugbau KG [STAMO] (Germany) without a Website.
Torque Master (US) with their Torque Master Website.
Valley Engineering (US) with their Valley Engineering Website and Culver Props Website.
VW Engine Centre (Australia) with their VW Engine Centre Website.
Oskar Westermayer (Austria) without a Website.
Zöllner (Germany) without a Website.
Firms and individuals known to have offered full Volkswagen conversions for experimental aircraft, now or in the past, and which do not have a separate page in this Compilation, are:
Ackerman, Charles (US); A colleague of William S. Evans in Volksplane VP-1, VP-2; Sold conversion instructions from La Jolla, California. Classified ads in SA1977-1980.Firms known to have offered PSRU specifically for full Volkswagen conversions, now or in the past, are:
Able.
Aero Kinetics (US) uses chain drives for VW conversions. KP5/02.
11244 Aero Lane, SE
Yelm, WA 98597
(360) 458-8775
Gyrodynamics built chain drives, plans of which can be found on e-Bay in CD form. Classified ads in SA1979-1980.
Of the many versions of VW engines, the following are known to have been converted to 1/2 VW engines for aircraft use. The format will be to list all of the individual engine designs first, and then to list the firms that now are or formerly had been converting that individual engine to a two-cylinder engine for aircraft propulsion and have a separate page in this Compilation. References, where appropriate, and known Applications, for which the identity of the converter has not been specified, are given. The approximate horsepower is given pretty well by the equation discussed for the full VW conversions.
O-48 - - {3.346 / 2.717 / 47.8} / {85 / 69 / 783}
Same stroke as O-51, O-56.
1/2 VW 1566 cc ( ~ 26hp).
Converters: Global (US).
O-51 - - {3.464 / 2.717 / 51.2} / {88 / 69 / 839}
Same stroke as O-48, O-56.
1/2 VW 1679 cc ( ~ 28hp).
Converters: Hummel (US).
O-55 -- {3.543 / 2.835 / 55.9} / {90 / 72 / 916}
1/2 VW 1832 cc ( ~ 31hp).
Converters: Ital-American, IAME, KFM (Italy).
O-56 - - {3.622 / 2.717 / 56.0} / {92 / 69 / 917}
Same bore as O-63, O-67.
Same stroke as O-48, O-51.
1/2 VW 1835 cc ( ~ 31hp).
Converters: Global (US); Hummel (US); Watson (US).
O-61 - - {3.559 / 3.087 / 61.4} / {90.4 / 78.4 / 1006}
1/2 VW 2013 cc ( ~ 34hp).
Converters: IMAER, Retimotor (Brazil).
O-63 - - {3.622 / 3.071 / 63.3} / {92 / 78 / 1037}
Same bore as O-56, O-67.
Same stroke as O-66.
1/2 VW 2074 cc ( ~ 35hp).
Converters: Carr Precision (US); Great Plains/Carr (US); Hummel (US); Mosler, TEC (US).
O-66 - - {3.701 / 3.071 / 66.1} / {94 / 78 / 1083}
Same bore as O-73.
Same stroke as O-63.
O-67 - - {3.622 / 3.228 / 66.5} / {92 / 82 / 1090}
Same bore as O-56, O-63.
1/2 VW 2180 cc ( ~ 36hp).
Converters: Great Plains/Carr (US).
O-73 - - {3.700 / 3.386 / 72.8} / {94 / 86 / 1143}
Same bore as O-66.
1/2 VW 2287 cc ( ~ 45hp).
Converters: Hummel (US).
Firms known to have offered two-cylinder 1/2 Volkswagen conversions for experimental aircraft, now or in the past, and which have a separate page in this Compilation, are:
Carr Precision Industries (US) with their Carr Precision Website.
Global Machine Tool (US) without a Website.
Great Plains Aircraft Supply Co. (US) with their Great Plains Website.
Homebuilt Aircraft Products, Inc. [HAPI] (US) without a Website.
Hummel Engines (US) with their Hummel Engines Website and the Hummel Aviation Website.
Industria Mecânica E Aeronáutica LTDA [IMAER], Retimotor (Brazil) without a Website.
Ital-American Motor Engineering [IAME], KFM (Italy) without a Website.
Milholland Better Half VW (US) with his Better Half VW Website.
Mosler Motors, TEC (US) without a Website.
Preceptor (US) with their Preceptor Website.
Gary Watson (US) without a Website.
Firms known to have offered two-cylinder 1/2 Volkswagen conversions for experimental aircraft, now or in the past, and which do not have a separate page in this Compilation, are:
Bronson, Bill of 2540 Hillcrest, High Ridge, Missouri 63049, phone (314) 677-4047, sells narrative and plans for building the "Smooth1/2 VW". He also answers questions about 1/2 VW conversions in the "Power On" section of the EAA Sport Pilot & Light Sport Aircraft magazine (SP), which was called the EAA Experimenter magazine prior to the 4/04 issue. SP4/94 and classified ads in SP1994-present.
McGill, Gary of Glendale, Arizona sold plans for 1/2 VW conversions. KP4/00, 4/01 and classified ads in SA1996-2001.
Moore, Bob was involved in 1/2 VW conversions and still had an active Website in 2001.