Cleone Motors of St. Louis, Missouri built both two-stroke cycle air-cooled Cleone engines and light aircraft to use them in c.1930. All of these Cleone two-stroke engines were reported to have the cylinders directly opposite each other with both cylinders firing simultaneously. This can be seen clearly in the photos of a Cleone engine (probably an E-30) on Joe Gertler's Website. To distinguish this cylinder configuration from that of Lawrance (and others) that had pistons moving in the same direction simultaneously, it should be remarked that a 3-throw crankshaft must have been incorporated. One piston had an ordinary connecting rod while the second had a forked connecting rod to make room for the ordinary rod of the first piston between the two tines. This technique was developed by Anzani (France) in the late 1920s. Herschel Smith describes this mechanism (including a sketch) on p. 200 of his book (S). The Cleone crankshaft was supported by plain bronze bearings with a ball bearing used to carry the thrust load. Some sources say that Cleone engine production was taken over by Cyclomotor. However, the specifications (Ae39) indicate that the bore of the Cyclomotor A-2-25 is in-between those published (Ae39) for the Cleone D-25 and E-30 engines. Also, the reported bearing configurations are quite different between the engines of the two companies. Thus, the relationships among the Cleone and Cyclomotor engines remain uncertain.
O-40 (2-Stroke) -- {N/A / N/A / 40} / {N/A / N/A / 655}
2cyl; Glider Engine; 8-15hp; 1930; Wt = 25#; TC = none.
Engine built for detachable mounting on gliders as an auxiliary powerplant.
aerofiles.com; Ae39; J4, J5, J9.
Applications: (US) Burkholt BGP-1 [10423]; Cessna CPG-1 [344M] powered version of their CG-2 glider.
O-63 (2-Stroke) -- {3.375 / 3.5 / 62.6} / {85.7 / 88.9 / 1026}
Same stroke as O-77.
2cyl; E-30; 25hp@3000rpm; 1930; Wt = 43#; TC = none.
Successor to the O-77 (D-25). An example of the E-30 is in the Seattle Museum of Flight.
aerofiles.com; Ae39; AI6/73 (Zimmerman application); APW60 ("Baby" Cessna application); J4, J5, J9.
Applications: (US) American Eagle Eaglet 130 [281N, 286N, and 294N are listed]; Bell (Oscar P.) biplane [11055]; Cessna EC-1 "Baby Cessna" [133V, 199V]; Cleone 5-M Paraquet [X712M], 7-M & 74-E [548N]; Cycloplane A-1 prototype [144W]; Gorenflo-Brady midwing [875Y]; Locke Monoplane [529V]; Truman 33 [12730]; Zimmerman (Charles H.), et al. low aspect-ratio twin-engined experimental craft that was built in 1935, but not flown - concept was revived by Zimmerman in the Vought V-173 and XF5U-1.
2cyl; EG-30; 30hp@3600rpm; 1930; Wt = 60#; TC = none.
As E-30, but geared to 0.5.
aerofiles.com; Ae39; J4, J5, J9.
Applications: see above for E-30; it is not clear which versions were used in which aircraft.
O-77 (2-Stroke) -- {3.75 / 3.5 / 77.3} / {95.3 / 88.9 / 1267}
Same stroke as O-63.
2cyl; D-25; 25hp@2600rpm; 1930; Wt = 50#; TC = none.
Apparently succeeded by E-30, EG-30.
aerofiles.com; Ae39; J4, J5, J9.
Applications: see above for E-30; it is not clear which versions were used in which aircraft.