HAPI engines are Volkswagen auto engines converted to full or 1/2 VW aircraft engines by Homebuilt Aircraft Products, Inc. (H.A.P.I.), initially of Calexico, California and later of Eloy, Arizona. Although the firm preferred the H.A.P.I. abbreviation, the Compiler has chosen to use HAPI, as many others have done. HAPI was founded in 1977 by Rex Taylor and his son Patrick while they were designing a light aircraft kit, the Hapicraft. The aircraft never materialized, but they became deeply involved in VW conversions in both kit and completely assembled form. Rex Taylor wrote an extensive series of articles in the EAA Sport Aviation magazine about VW conversions in general, and HAPI conversions in particular. The articles can be found in SA2/79 and in a ten-part series from SA12/79 through SA9/80. HAPI continued in business until 1989, when the engine assets were sold to Mosler Motors and Rex Taylor retired.
O-66 - - {3.701 / 3.071 / 66.1} / {94 / 78 / 1083}
Same bore and stroke as O-132.
Same bore as O-117.
2cyl; HAPI Hornet; 25-35hp@3250rpm; 1983-1989; Wt = 74#.
Carbureted engine with single ignition.
BGP.
Applications: None found.
O-97 - - {3.366 / 2.717 / 96.7} / {85.5 / 69 / 1585}
Same stroke as O-102, O-112, O-117.
4cyl; HAPI Model 50; 50hp@3200rpm; 1979-1989; Wt = 152#.
Carbureted engine with optional single or dual ignition; starter and alternator were standard equipment except on Model 50-E.
SA2/79.
Applications: None found.
O-102 - - {3.465 / 2.717 / 102.4} / {88 / 69 / 1679}
Same stroke as O-97, O-112, O-117.
4cyl; HAPI Model 55; 55hp@3200rpm; 1983-1989; Wt = N/A.
Carbureted engine with optional single or dual ignition; starter and alternator were standard equipment except on Model 55-E.
BGP.
Applications: None found.
O-112 - - {3.622 / 2.717 / 112.0} / {92 / 69 / 1835}
Same stroke as O-97, O-102, O-117.
4cyl; HAPI Model 60; 60hp@3200rpm; 1979-1989; Wt = 152#.
Carbureted engine with optional single or dual ignition; starter and alternator were standard equipment except on Model 60-E. A turbocharged version also was available.
SA2/79.
Applications: (US) Bounsall Super Prospector.
O-117 - - {3.701 / 2.717 / 116.9} / {94 / 69 / 1915}
Same bore as O-66, O-132.
Same stroke as O-97, O-102, O-112.
4cyl; HAPI Model 75 Magnum; 75hp@3200rpm; 1983-1989; Wt = N/A.
Carbureted engine with optional single or dual ignition; starter and alternator were standard equipment except on Model 75-E.
BGP.
Applications: None found.
O-132 - - {3.701 / 3.071 / 132.1} / {94 / 78 / 2165}
Same bore and stroke as O-66.
Same bore as O-117.
4cyl; HAPI Model 82 Magnum Plus; 82hp@3400rpm; 1983-1989; Wt = N/A.
Carbureted engine with optional single or dual ignition; starter and alternator were standard equipment except on Model 82-E.
BGP.
Applications: None found.