The de Havilland Gipsy Major or Gipsy IIIA is a four-cylinder, air-cooled, inverted inline engine used in a variety of light aircraft produced in the 1930s, including the famous Tiger Moth biplane. Many Gipsy Major engines still power vintage aircraft types worldwide today.
The Thielert Centurion is a series of Diesel cycle aircraft engines for general aviation originally built by Thielert, which was bought by Aviation Industry Corporation of China's Tecnify Motors subsidiary and is currently marketed by Continental Motors. They are based on heavily modified Mercedes-Benz automotive engines.
The Continental C90 and O-200 are a family of air-cooled, horizontally opposed, four-cylinder, direct-drive aircraft engines of 201 in³ displacement, producing between 90 and 100 horsepower.
The Continental O-300 and the C145 are a family of air-cooled flat-6 aircraft piston engines built by Teledyne Continental Motors.
The Lycoming O-320 is a large family of naturally aspirated, air-cooled, four-cylinder, direct-drive engines produced by Lycoming Engines. They are commonly used on light aircraft such as the Cessna 172 and Piper Cherokee. Different variants are rated for 150 or 160 horsepower. As implied by the engine's name, its cylinders are arranged in horizontally opposed configuration and a displacement of 320 cubic inches (5.24 L).
The Continental R-670 was a seven-cylinder four-cycle radial aircraft engine produced by Continental displacing 668 cubic inches and a dry weight of 465 lb (211 kg). Horsepower varied from 210 to 240 at 2,200 rpm. The engine was the successor to Continental's first radial engine, the 170 hp Continental A-70. This engine was used on many aircraft in the 1930s and 1940s. The R-670 was widely used in the PT-17 Stearman primary training aircraft of the U.S. military.
The Continental O-190 is a series of engines made by Continental Motors beginning in the 1940s. Of flat-four configuration, the engines produced 75 hp (56 kW) or 85 hp (63 kW) respectively.
The Franklin O-335 was an American air-cooled aircraft engine of the 1940s. The engine was of six-cylinder, horizontally-opposed layout and displaced 335 cu in (5.5 L). The power output of later variants was 225 hp (168 kW).
The LeBlond radial engines, later produced under the name Ken-Royce, were a family of 3-cylinder, 5-cylinder and 7-cylinder, air-cooled radial engines for aircraft, built in the 1930s by the LeBlond Aircraft Engine Corporation until the operation was sold to Rearwin Airplanes in 1937 and renamed Ken-Royce Engines.
The Franklin O-150 was an American air-cooled aircraft engine of the late 1930s. The engine was of four-cylinder, horizontally-opposed layout and displaced 150 cu in (2 L). The power output was nominally 40 hp (30 kW).
The Franklin O-175 was an American air-cooled aircraft engine of the 1940s. The engine was of horizontally-opposed four-cylinder and displaced 175 cu in (2.9 L). The power output was nominally 80 hp (60 kW). A later variant was designated O-180, despite sharing the same displacement.
The Benz Bz.IV was a German six-cylinder, water-cooled, inline engine developed for aircraft use. Deliveries began in 1916 and some 6,400 were produced.
The Porterfield Collegiate is an American-built two-seat training and touring monoplane built by the Porterfield Aircraft Corporation of Kansas City.
The Bristol Cherub is a British two-cylinder, air-cooled, aircraft engine designed and built by the Bristol Aeroplane Company. Introduced in 1923 it was a popular engine for ultralight and small aircraft in the 1930s.
The Continental A40 engine is a carbureted four-cylinder, horizontally opposed, air-cooled aircraft engine that was developed especially for use in light aircraft by Continental Motors. It was produced between 1931 and 1941.
The Armstrong Siddeley Ounce was a small two-cylinder aero engine developed by Armstrong Siddeley in 1920. The engine was originally conceived as a test piece but ran very well and was put into production for early ultralight aircraft and use in target drones. The Ounce used two cylinders from the preceding Jaguar I radial engine.
The Lycoming O-145 is a family of small, low-horsepower, four-cylinder, air-cooled engines. It was Lycoming Engines' first horizontally opposed aircraft engine and was produced from 1938 until the late 1940s. The family includes the reduction-geared GO-145. The O-145 received its Approved Type Certificate on 13 Jun 1938.
The Continental Tiara series are a family of air-cooled, horizontally opposed aircraft engines. Designed and built by Continental Motors/TCM, the Tiara series were commercially unsuccessful, costing the company millions of dollars.
The Menasco M-50 was an American four-cylinder horizontally-opposed aircraft engine.
The Diesel Air Dair 100 is an opposed-piston diesel aircraft engine, designed and produced by Diesel Air Ltd of Olney, Buckinghamshire for use in airships, home-built kitplanes and light aircraft. The prototype was built in the 1990s and exhibited it at PFA airshows. Although Diesel Air engines have been fitted to an AT-10 airship and to a Luscombe 8A monoplane, production numbers have been very limited.
