The Norton NR642 (Originally the Aerotor 90) is a British aircraft engine that was designed and produced by Norton Motorcycle Company in the 1990s for use in light aircraft (particularly by amateur constructors) and UAVs.
[1] It is a 588 cc (35.9 cu in) displacement[2] petrol engine design, with a heavy-duty[1] 2.94:1[2] reduction gearbox.
[1][2] It was designed to meet JAR-E[2] and FAR 23 regulatory requirements.
[2] The NR642 first flew in late 1989, with two units installed on a Rutan Long-EZ to create what its builder called a "Twin EZ".
[3] Data from Lambert 1991, p.709 Related lists