Lotus engines were built by the famous racing and sports car firm Lotus Cars, Ltd. of Norwich, Norfolk, UK. They built the two HOAE below for use in remotely piloted vehicles (RPV) and ultralight aircraft. Lotus sold the manufacturing rights for these engines in c.1985 to INAV, Ltd., another UK firm, who renamed the engines as the Magnum series. INAV also purchased the well-known US homebuilt aircraft firm Monnett Experimental Aircraft Co. of Oshkosh, Wisconsin at about that time.
O-29 -- {2.835 / 2.323 / 29.3} / {72 / 59 / 480}
Same bore and stroke as O-59.
2cyl; Lotus 225, INAV Magnum 225; 25hp@5000rpm; 1984-1988; Wt = 31#.
Single- or dual-, capacitor-discharge ignition available; geared to 0.5 by driving the propeller from the camshaft. The British Aerospace Stabileye Mk.4 mini-RPV was originally designed for this engine, but first flew with an NGL WAEL 342 engine.
aerofiles.com; BGP; J84-85toJ87-88; SA10/85.
Applications: (UK) British Aerospace Stabileye Mk.4 mini-RPV. (US) Rutan Model 61 Lotus (also known as Mercury).
O-59 -- {2.835 / 2.323 / 58.6} / {72 / 59 / 961}
Same bore and stroke as O-29.
4cyl; Lotus 450, INAV Magnum 450; 50hp@5000rpm; 1984-1988; Wt = 56#.
Single- or dual-, capacitor-discharge ignition available; geared to 0.5 by driving the propeller from the camshaft.
BGP; J84-85toJ87-88; SA10/85.
Applications: None found.