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.

Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Object Details

Date

Circa 1941

Country of Origin

United States of America

Type

PROPULSION-Reciprocating & Rotary

Manufacturer

Continental, Inc.

Physical Description

Type: Reciprocating, 14 cylinders, 2 rows, radial, air-cooled, direct fuel injection, single-speed centrifugal supercharger
Power rating: 652 kW (875 hp) at 2,600 rpm
Displacement: Not available
Bore and Stroke: Not available
Weight: 630 kg (1,388 lb)

Dimensions

Height 134.6 cm (53 in.), Length 176.5 cm (69.5 in.), Width 132.7 cm (52.25 in.)

Materials

Steel, Aluminum, paint, Plastic, Copper, Stainless Steel, Rubber, Magnesium

Inventory Number

A19710891000

Credit Line

Transferred from the U.S. Navy

Data Source

National Air and Space Museum

Restrictions & Rights

Open Access (CCO)
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