Warner Scarab Explained
The Warner Scarab is an American seven-cylinder radial aircraft engine, that was manufactured by the Warner Aircraft Corporation of Detroit, Michigan 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 125abbr=onNaNabbr=on at 2,050 rpm from 422abbr=onNaNabbr=on with a dry weight of 285abbr=onNaNabbr=on.
Scarab Junior:A 5-cyl. version introduced in 1930 developing 90abbr=onNaNabbr=on at 2,125 rpm from 301abbr=onNaNabbr=on with a dry weight of 230abbr=onNaNabbr=on.
Super Scarab SS-50/50A: Increased cylinder bore to 4.625 inches to develop 145abbr=onNaNabbr=on at 2,050 rpm from 499abbr=onNaNabbr=on with a dry weight of 303abbr=onNaNabbr=on.
Super Scarab SS-165: Increased compression ratio from 5.2:1 to 6.4:1 to develop 165abbr=onNaNabbr=on at 2,100 rpm with a dry weight of 341abbr=onNaNabbr=on.
Super Scarab SS-185: Increased cylinder bore to 4.875 inches, developing 185abbr=onNaNabbr=on at 2175 rpm from 555abbr=onNaNabbr=on, with a dry weight of 344abbr=onNaNabbr=on.
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 and the Fairchild 24 (UC-61 or Argus). Notably, in 1942, it was put into use powering the Sikorsky R-4, 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
External links
