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The Lion was a 12-cylinder W-block inline aircraft engine built by Napier & Son starting in 1917, and ending in the 1930s. A number of advanced features made it the most powerful engine of its day, and kept it in production long after contemporary designs had stopped production. It is particularly well known for its use on a number of racing designs, both in aircraft and racing boats.Early in World War I, Napier were contracted to build aero engines from other companies designs: initially a Royal Aircraft Factory model and then Sunbeams. Both proved to be rather unreliable, and in 1916 Napier decided to design their own instead. Reasoning that the key design criteria were high power, light weight, and low frontal area, the engine was laid out with its 12 cylinders in what they called a "broad arrow" - three banks of four cylinders sharing a common crankcase. This suggested the designs first name, the Triple-Four. Today these designs, of which there were only a few, are referred to as a W-block. The engine was also advanced in form, using four valve heads with twin overhead camshafts, and a single block milled from aluminum instead of the more common separate-cylinder steel construction used on almost all other designs.
The newly-renamed Lion's design was completed in 1917, and the first hand-built prototypes ran late that year. It was fitted to a De Havilland D.H.9 in early 1918Events January January 8 President Woodrow Wilson announces his " Fourteen Points" for the aftermath of World War I. February February 3 The Twin Peaks Tunnel begins service in San Francisco as the longest streetcar tunnel in the world (11,920 feet long)., proving to have many cooling problems. In addition the milled block turned out to be difficult to build with any accuracy and they reverted to separate cylinders, although they remained aluminum. Both of these problems were worked out by the middle of the year and the engine entered production in June. The first Lion I versions delivered 450 hpThe horsepower hp is the name of several non-metric units of power. In scientific discourse the horsepower is rarely used due to the various definitions and the existence of an SI unit for power, the watt (W). However, the idea of horsepower persists as a (335 kW) from their 25 litreThe litre (or liter in US) is a metric unit of volume. The litre is not an SI unit, but is "accepted for use with the International System". The symbol for the litre is the lowercase letter l or the uppercase letter L . A cursive or script small letter ls. It then took the crown of the most powerful engine from the Liberty L-12 , the excellent USThe United States of America also referred to as the United States U. America ¹ or the States is a federal republic in central North America, stretching from the Atlantic in the east to the Pacific Ocean in the west. It shares land borders with Canada in wartime design of 400 hp (300 kW).
As the most powerful engine available (particularly after a turbochargerA turbocharger is a device used in internal-combustion engines to increase the power output of the engine by increasing the mass of oxygen and fuel entering the engine. A key advantage of turbochargers is that they offer a considerable increase in engine became an option in 1922Events January 7 Dali Eireann ratifies the Anglo-Irish Treaty by 64-57 votes. January 10 Arthur Griffith is elected President of Dail Eireann January 11 First successful insulin treatment of diabetes. January 12 British government releases Irish prisoners), the Lion went on to be a huge commercial success. Through the years between the wars the Lion was ubiquitous, and Napiers manufactured little else. They stopped making cars in 1925, and little thought was given to replacing their world-famous product. Between the wars it powered over 160 different types of aircraft.
In highly-tunedEngine swap with a Tuned VTEC engine of a Honda Civic CRX Engine tuning is the modification or design of internal combustion engines to yield more performance, either in terms of power output or economy. It is a popular pastime with amateur mechanics and racing forms the engine could reach 1,300 hp (970 kW), and it broke a host of world records: height, air speed, and long distance in aircraft, water speed (delivering 1,375 hp (1,025 kW) in a highly tuned Lion for 100 miles per hour (160 km/h) in 1933Centuries: 19th century 20th century 21st century Decades: 1880s 1890s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s Years: 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 See also 1933 in aviation 1933 in film 1933 in literature 1933 in mu) and even land speed: Lions powered many of Sir Malcom Campbell 's record breakers (including over 250 mph (400 km/h) in 1932) and John Cobb's 394 MPH Railton in 1947 - a record that came well after the Lion had passed its prime and yet was to stand for 32 years. Lions powered successful entrants in the most prestigious event in air racing, the Schneider Cup, in 1922 and 1927, but were then dropped by Supermarine in favour of a new, especially designed for racing, engine from Rolls-Royce.
In the 1930s a new generation of much larger and more powerful engines started to appear, and the Lion was clearly past its prime. Gradually, they fell further and further behind. By the time the Bristol Hercules and the Rolls-Royce Merlin arrived in the late 1930s, the Lion was too small and old-fashioned.
In order to address this problem, Napier started the design of two new engines using the even more compact H engine layout. The 16-cylinder Rapier produced 400 hp (300 kW), the 24-cylinder Dagger delivered just under to 1000 hp (750 kW). However these were both smaller than contemporary designs from other companies, and Napier had to start fresh with a new sleeve valve design, which eventually matured into the superb Sabre.
