A V engine , sometimes called a Vee engine , is a common configuration for internal combustion engines . It consists of two cylinder banks —usually with the same number of cylinders in each bank—connected to a common crankshaft . These cylinder banks are arranged at an angle to each other, so that the banks form a "V" shape when viewed from the front of the engine.
26-420: V engines typically have a shorter length than equivalent inline engines , however the trade-off is a larger width. V6 , V8 and V12 engines are the most common layout for automobile engines with 6, 8 or 12 cylinders respectively. The first V engine, a two-cylinder V-twin, was designed by Wilhelm Maybach and used in the 1889 Daimler Stahlradwagen automobile. The first V8 engine was produced in 1903, in
52-489: A "straight" (inline) layout today use a single cylinder head that serves all the cylinders. Engines with a "V" layout or "flat" layout typically use two cylinder heads (one for each cylinder bank ), however a small number of 'narrow-angle' V engines (such as the Volkswagen VR5 and VR6 engines) use a single cylinder head spanning the two banks. Most radial engines have one head for each cylinder, although this
78-530: A V6 layout. Similarly, straight-eight engines were popular in the 1920s to 1940s, however they were replaced by the more compact V8 layout. Many straight engines have been produced for aircraft, particularly from the early years of aviation and through the interwar period leading up to the Second World War. Straight engines were simpler and had low frontal area, reducing drag, and provided better cockpit visibility. Straight sixes were especially popular in
104-735: A single overhead camshaft (SOHC) engine, the camshaft may be seated centrally between valve rows, or directly above a single row of valves (replacing rocker arm actuation with tappets ). SOHC engines were widely from the 1960s to 1990s. (eliminating pushrods but still utilizing rocker arms) Double overhead camshaft (DOHC) engines seat a camshaft directly above each row of offset valves (intakes inboard, exhausts outboard). DOHC designs allow optimal crossflow positioning of valves to provide higher- RPM operation. They are typically larger in size (especially width) than equivalent OHV or SOHC engines. Even though more components raise production costs, DOHC engines seen widespread use in automobile engines since
130-433: A V engine has a shorter length but is wider. This effect increases with the number of cylinders in the engine; the length difference between V-twin and straight-twin engines might be insignificant, however V8 engines have a significantly smaller length than straight engines. Compared with the less common flat engine , a V engine is narrower, taller and has a higher center of mass . The "V-angle" (or "included angle") between
156-511: A V12 engine is that of perfect primary and secondary balance. For V engines with fewer cylinders, the engine balance will depend on factors such as the firing interval, crankshaft counterweights and whether balance shafts are present. The crankpins on a V engine are usually shared by two cylinders from opposing banks, with an offset between the two cylinders. Alternative configurations are separate crankpins per cylinder (such as several V-twin engines) or articulated connecting rods (for example,
182-404: A single failed head on a single cylinder can be changed instead of a larger, much more expensive unit fitting all the cylinders. Such a design also allows engine manufacturers to easily produce a 'family' of engines of different layouts and/or cylinder numbers without requiring new cylinder head designs. In a flathead ( sidevalve ) engine, all of the valvetrain components are contained within
208-410: A single row, rather than radially or in two or more cylinder banks. A straight engine is easier to build than an equivalent flat engine or V engine , as it uses one cylinder head rather than two. Inline engines are also narrower than flat engines or V engines; however, they are longer and can be taller. The engine balance characteristics of a straight engine depend on the number of cylinders and
234-672: A wide range of smaller aircraft around the world, including on the Tiger Moth biplane, and helped made the configuration popular for light aircraft. Menasco and Fairchild-Ranger in the United States, Renault in France, Walter in Czechoslovakia, and Hirth in Germany all built a similar range of engines which were popular in their respective markets. The aviation use of term " inline engine "
260-399: Is used more broadly than for straight engines, since it also applies to other configurations where the cylinders are located in rows (e.g. V engines , W engines , H engines and horizontally opposed engines ). Some straight aircraft engines have used an inverted engine configuration, whereby the crankshaft is at the top of the engine and the pistons hang downwards from it. Advantages of
286-412: Is used to reduce the height of the engine, so that it can be located under the floor of the train or bus. The straight-three and straight-four configurations are the most common layouts for three- and four-cylinder engines respectively. Straight-five engines are occasionally used, most recently by Audi and Volvo. Straight-six engines were common prior to the 1990s, however most six-cylinder engines now use
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#1732859249105312-479: Is usually of the monobloc form wherein the head is made as an integral part of the cylinder. This is also common for motorcycles, and such head/cylinder components are referred to as barrels . Some engines, particularly medium- and large-capacity diesel engines built for industrial, marine, power generation, and heavy traction purposes (large trucks, locomotives , heavy equipment , etc.) have individual cylinder heads for each cylinder. This reduces repair costs as
338-419: The cylinder banks varies significantly between engines. Some engines have used a V-angle of 180 degrees (the same angle as a flat engine ), such as several Ferrari V12 engines. At the other end of the scale, the 1922-1976 Lancia V4 engine and the 1991–present Volkswagen VR6 engine use V-angles as small as 10 degrees, along with a single cylinder head used by both banks of cylinders. The engine balance of
364-560: The cylinder head sits above the cylinders , forming the roof of the combustion chamber . In sidevalve engines the head is a simple plate of metal containing the spark plugs and possibly heat dissipation fins . In more modern overhead valve and overhead camshaft engines, the head is a more complicated metal block that also contains the inlet and exhaust passages, and often coolant passages , Valvetrain components, and fuel injectors . A piston engine typically has one cylinder head per bank of cylinders . Most modern engines with
390-425: The firing interval . When a straight engine is mounted at an angle from the vertical it is called a slant engine . Notable slant engines include the 1959-2000 Chrysler Slant-6 engine , 1961-63 Pontiac Trophy 4 engine and the 1968-1981 Triumph Slant-4 engine . Some buses and diesel multiple unit trains take this concept further by mounting the engines horizontally (i.e. with a slant angle of 90 degrees). This
416-437: The intake manifold to the combustion chamber , and exhaust ports route combustion waste gases out the combustion chamber to the exhaust manifold . Valves open and close the ports, with the intakes offset fore-and-aft from the exhausts. The head also contains the spark plugs , and on water-cooled engines, the coolant passages. A single camshaft located in the engine block uses pushrods and rocker arms to actuate all
442-419: The 1935 Daimler-Benz DB 601 V12 engines. It is common practice for V engines to be described with "V # " notation, where # represents the number of cylinders. Configurations of V engines which have reached production are as follows: Straight engine The straight engine (also called inline engine ) is a configuration of multi-cylinder piston engine where all of the cylinders are arranged in
468-547: The First World War, and most German and Italian and some British aircraft used descendants of Daimler's pre-war inline six. Prominent examples include the German Mercedes D.III and BMW IIIa , Italian Isotta Fraschini V.4 and British Siddeley Puma . The British de Havilland Gipsy family of engines and their descendants included straight-four and straight-six upright and inverted air-cooled engines which were used on
494-476: The block , therefore the head is usually a simple plate of metal bolted to the top of the engine block . Sidevalve engines were once universal but are now largely obsolete in automobiles, found almost exclusively in small engines such as lawnmowers, weed trimmers and chainsaws. Intake Over Exhaust (IOE) engines combined elements of the sidevalve and overhead valve designs. Used extensively in American motorcycles in
520-402: The cockpit. In motorcycling, the term "in-line" is sometimes used narrowly, for a straight engine mounted in line with the frame. A two-cylinder straight engine mounted across the frame is sometimes called a parallel twin. Other times, motorcycling experts treat the terms parallel, straight, and inline as equivalent, and use them interchangeably. Cylinder head In a piston engine ,
546-446: The early 1900s, the IOE engine remained in production in limited numbers until the 1990s. IOE engines are more efficient than sidevalve engines, but also more complex, larger and more expensive to manufacture. In an overhead valve (OHV) or overhead camshaft (OHC) engine, the cylinder head contains several airflow passages called ports ; intake ports deliver the fuel+air intake charge from
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#1732859249105572-630: The form of the Antoinette engine designed by Léon Levavasseur for racing boats and airplanes . The first V12 engine was produced the following year by Putney Motor Works in London , again for use in racing boats. The first V6 engine to reach production appeared soon after in 1908, by the Deutz Gasmotoren Fabrik in Germany for use as a generator for gasoline-electric railway engines . However, it
598-421: The inverted arrangement include a raised thrust line for improved clearance for the propeller, which either allows for the use of a larger, more efficient propeller, or for shorter undercarriage. Since the thrust line is higher, the engine can be mounted lower in the airframe, improving visibility forward, which is no longer blocked by the cylinder heads. It also allows for a simpler exhaust to keep gasses clear from
624-478: The such as the Rolls-Royce Merlin aero engine). Some airplanes of the 1920s and 1930s used inverted engines , whereby the crankshaft is located at the top of the engine and the cylinder heads are at the bottom. Advantages include better visibility in a single-engined airplane, a higher thrust line, and resultant increased ground clearance for the propeller. Examples include the 1928 Argus As 10 V8 engine and
650-466: The valves. OHV engines are typically more compact than equivalent OHC engines, and fewer parts mean cheaper production, but they have largely been replaced by OHC designs, except in some American V8 engines. An overhead camshaft (OHC) engine locates the camshaft(s) in the cylinder head above the combustion chamber. Eliminating pushrods lessens valvetrain inertia and provides space for optimized port designs, both providing increased power potential. In
676-520: Was not until 1950 that the V6 engine was used in series production automobiles, with the first example being the Lancia V6 engine . This V6 engine used a 60-degree V angle and separate crankpins for each cylinder, to reduce the vibration issues experienced by earlier attempts at production V6 engines. Compared with an equivalent inline engine (the most common configuration for engines with less than six cylinders),
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