A 7-cyl. air-cooled radial engine introduced in 1928. With a bore and stroke of 4.25 inches and a compression ration of 5.2:1, the Scarab developed 125 hp (93 kW) at 2,050 rpm from 422 cu in (7 l) with a dry weight of 285 lb (129 kg).
A 5-cyl. version introduced in 1930 developing 90 hp (67 kW) at 2125 rpm from 301 cu in (5 l) with a dry weight of 230 lb (104 kg).
Amongst the many uses for the Scarab, the engine was fitted to the Cessna Airmaster and the Fairchild 24 (UC61 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-WWII era aircraft, in large part because of good parts availability due to the engines having been used on WWII Fairchild UC61s 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.