Four-stroke Cycle (1876)

The cycle of Otto's four-stroke engine is commonly simplified as “suck, squeeze, bang, and blow”.

Otto revisits the internal combustion engine.

German engineer Nikolaus Otto (1832-1891) was responsible for one of the great developments in motorized vehicles with the Invention of his four-stroke cycle internal combustion engine.

After developing an interest in technology, he began designs for a four-stroke engine based on Lenoir's earlier design for a two-stroke cycle. In 1864 he set" up N. A. Otto and Cie alongside Eugene Langer, creating the world's first engine manufacturers. In 1872, he employed Gottlieb Daimler and Wfihelm Maybach as technical director and chief designer, respectively. In 1876 the· first practical four-stroke engine was constructed. The four strokes are an intake stroke, where the piston moves down to allow a fuel-air mixture into the combustion chamber; a compression stroke, where the piston moves back up to compress the gases; a combustion or power stroke, where a spark ignites the fuel and the piston is forced down again; and a final exhaust stroke, where the piston

moves up to expel spent fuel via the exhaust valve. Although Otto patented his design in 1877 the patent was overturned in 1886 and instead· granted to Frenchman Alphonse Beau de Rochas, who never built a working engine.

Initially, combustion engines were stationary as they could not be adapted to run on liquid fuel and so required a pilot light. Otto solved this problem in 1884 with the invention of a magneto ignition system that created the spark needed for the-power stroke. This increased the practicality .of the four-stroke engine and allowed it to be used by Daimler and Maybach in the first motorcycles and automobiles.