The Warner Scarab is an American seven-cylinder

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance (geometry), a directional coordinate in a polar coordinate system * Radial set * A ...

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbin ...

, that was manufactured by the Warner Aircraft Corporation of

Detroit Detroit ( , ) is the List of municipalities in Michigan, most populous city in the U.S. state of Michigan. It is situated on the bank of the Detroit River across from Windsor, Ontario. It had a population of 639,111 at the 2020 United State ...

Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...

in 1928 through to the early 1940s. In military service the engine was designated R-420.

Variants

;Scarab S-50: A 7-cyl. air-cooled radial engine introduced in 1928. With a bore and stroke of 4.25 inches and a compression ratio of 5.2:1, the Scarab developed at 2,050 rpm from with a dry weight of . ;Scarab Junior:A 5-cyl. version introduced in 1930 developing at 2,125 rpm from with a dry weight of . ;Super Scarab SS-50/50A: Increased cylinder bore to 4.625 inches to develop at 2,050 rpm from with a dry weight of . ;Super Scarab SS-165: Increased compression ratio from 5.2:1 to 6.4:1 to develop at 2,100 rpm with a dry weight of . ;Super Scarab SS-185: Increased cylinder bore to 4.875 inches, developing at 2175 rpm from , with a dry weight of . ;R-420:Military designation of the Scarab. ;R-500:Military designation of the Super Scarab 165. ;R-550:Military designation of the Super Scarab 185. ;145: Alternative designation for the Warner Super Scarab SS-50/50A . ;165: Alternative designation for the Warner Super Scarab 165 . ;185: Alternative designation for the Warner Super Scarab 185 (Primarily a helicopter application).

Applications

Among the many uses for the Scarab, the engine was fitted to the

Cessna Airmaster The Cessna Airmaster, is a family of single-engined aircraft manufactured by the Cessna Aircraft Company. The Airmaster played an important role in the revitalization of Cessna in the 1930s after the crash of the aviation industry during the Gre ...

and the

Fairchild 24 The Fairchild Model 24, also called the Fairchild Model 24 Argus and UC-61 Forwarder, is a four-seat, single-engine monoplane light transport aircraft designed by the Fairchild Aviation Corporation in the 1930s. It was adopted by the United Sta ...

(UC-61 or Argus). Notably, in 1942, it was put into use powering the

Sikorsky R-4 The Sikorsky R-4 is a two-seat light helicopter that was designed by Igor Sikorsky with a single, three-bladed main rotor and powered by a radial engine. The R-4 was the world's first large-scale mass production, mass-produced helicopter and the ...

, the first helicopter to be put into production. Many of these reliable engines soldier on today, still powering the aircraft to which they were originally mounted. The Warner 145 and 165 hp engines are the most commonly seen of the small radials for US-built pre-World War II era aircraft, in large part because of good parts availability due to the engines having been used on World War II Fairchild UC-61s and Meyers OTWs. Warner engines are also in demand as realistically sized, though far more powerful, replacement powerplants for many replica or restored World War I era airplanes which were originally fitted with rotary engines.

Application list

Specifications (Scarab 50)

References

External links