Hummel engines are Volkswagen auto engines converted to full (four-cylinder) or 1/2 VW (two-cylinder) aircraft engines by James Morris (Morry) Hummel of Bryan, Ohio. Plans, as well as parts, are sold for both full and 1/2 VW engines. The 1/2 VW conversions are available with either the cut case or the full case. Hummel also is known for developing the Hummel Bird, two UltraCruiser versions and other light aircraft that can be powered by his conversions and for which he sells plans. The Hummel Bird is a design for an all-metal, single-seat aircraft of the same category as the Jeanie's Teeny designed by Cal Parker and the Windwagon designed by Gary Watson. Morry Hummel retired from both the engine and aircraft operations of the firm in 2002-2003. Scott Casler now builds and sells plans for the engines in his new facility in Coolidge, Arizona as Hummel Engines. Terry Hallet now does the aircraft development and sales, still from Bryan, Ohio, as Hummel Aviation. These new firms can be reached at the Hummel Engines Website and the Hummel Aviation Website, respectively. A nice biographical sketch of Morry Hummel can be found in the "About Us" section of the Hummel Aviation Website.
O-51 - - {3.464 / 2.717 / 51.2} / {88 / 69 / 839}
Same stroke as O-56, O-97, O-112.
2cyl; Hummel 28hp. 1/2 VW; 28hp@3600rpm; 1983-present; Wt = 85-103#.
Carbureted engine with dual magneto ignition, single magneto ignition, or single coil and battery ignition.
BGP; KP3/02, 2/03, 4/05, 4/06, 3/07, 3/08, 3/09; SA12/88.
Applications: {US} Hummel CA-2, UltraCruiser (Part 103 legal).
O-56 - - {3.622 / 2.717 / 56.0} / {92 / 69 / 917}
Same bore and stroke as O-112.
Same bore as O-63, O-133.
Same stroke as O-51, O-97.
2cyl; Hummel 32hp. 1/2 VW; 32hp@3600rpm; 1983-present; Wt = 81-103#.
Carbureted engine with dual or single magneto ignition.
BGP; KP3/02, 2/03, 4/05, 4/06, 3/07, 3/08, 3/09; SA12/88.
Applications: {US} Hummel CA-2, Hummel Bird, UltraCruiser (Part 103 legal).
O-63 - - {3.622 / 3.071 / 63.3} / {92 / 78 / 1037}
Same bore as O-56, O-112, O-133.
2cyl; Hummel 37hp. 1/2 VW; 37hp@3600rpm; 1983-present; Wt = 81-103#.
Carbureted engine with dual or single magneto ignition.
BGP; KP3/02, 2/03, 4/05, 4/06, 3/07, 3/08, 3/09; SA12/88; SP6/04.
Applications: {US} Hummel CA-2, Hummel Bird, UltraCruiser (Part 103 legal); Milholland Legal Eagle; Preceptor N3 Pup.
O-73 - - {3.700 / 3.386 / 72.8} / {94 / 86 / 1194}
Same bore and stroke as O-146.
2cyl; Hummel 45hp. 1/2 VW; 45hp@3400rpm; 2005-present; Wt = 84-102#.
Carbureted engine with dual or single magneto ignition.
Hummel Website; KP4/05, 4/06, 3/07, 3/08, 3/09, 9/09.
Applications: {US} Hummel Ultracruiser.
O-97 - - {3.366 / 2.717 / 96.7} / {85.5 / 69 / 1585}
Same stroke as O-51, O-56, O-112.
4cyl; Hummel 50hp. VW; 50hp@3600rpm; 1985-present; Wt = 140-160#.
Carbureted engine with dual or single magneto ignition.
BGP; KP3/02, 2/03; SA12/88.
Applications: None found.
O-112 - - {3.622 / 2.717 / 112.0} / {92 / 69 / 1835}
Same bore and stroke as O-56.
Same bore as O-63, O-133.
Same stroke as O-51, O-97.
4cyl; Hummel 60hp. VW; 60hp@3600rpm; 1985-present; Wt = 135-165#.
Carbureted engine with dual or single magneto ignition.
BGP; KP3/02, 2/03; SA12/88.
Applications: {US} Hummel UltraCruiser Plus.
O-133 - - {3.622 / 3.228 / 133.1} / {92 / 82 / 2180}
Same bore as O-56, O-63, O-112.
4cyl; Hummel 76hp. VW; 76hp@3600rpm; 1985-present; Wt = 137-167#.
Carbureted engine with dual or single magneto ignition.
BGP; KP3/02, 2/03; SA12/88.
Applications: None found.
O-146 - - {3.700 / 3.386 / 145.7} / {94 / 86 / 2387}
Same bore and stroke as O-73.
4cyl; Hummel 85hp. VW; 85hp@3600rpm; 2005-present; Wt = 137-167#.
Carbureted engine with dual or single magneto ignition.
Hummel Website; KP3/08, 3/09, 9/09.
Applications: {US} Hummel H-5 Sport Cruiser.