In 1925, Continental, a successful manufacturer of automotive engines, purchased the rights for a Burt-McCollum single-sleeve valve engine design. Believing this technology might replace poppet valves in aircraft engines, Continental announced the R-790 engine in 1927, incorporating single-sleeve valves initially installed on a Wright 9-cylinder engine. It was never fully tested, but followed by the 7-cylinder R-794, for which five engines were ordered by the U.S. Navy in 1934. It was tested, but did not go into production.

The Navy later sponsored a number of unconventional engine designs; however, few entered production. In the case of the 1939 XR-1740-2 development, the outcome was apparently typical of single-sleeve valve history. For example, Bristol’s Roy Fedden, one of history’s great aircraft engine experts, was unable to mass produce single-sleeve engines. Continental only became successful after reverting to poppet valves, and this artifact represents a seemingly simple new concept that could not compete with older, conventional technology better developed for practical application.