In automotive engineering, an engine is referred to as multi-valve (or multivalve) when each cylinder has more than two valves. The VQ engine is a 20 L to 40 L V6 Piston engine from Nissan. Modern automotive engineering is a branch of Vehicle engineering, incorporating elements of mechanical, electrical, electronic, software A poppet valve is a Valve consisting of a hole usually round or oval and a tapered plug usually a disk shape on the end of a shaft also called a valve stem

All poppet valve, four-stroke internal combustion engines have at least two valves per cylinder — one for intake of air and fuel, and another for exhaust of combustion products. A poppet valve is a Valve consisting of a hole usually round or oval and a tapered plug usually a disk shape on the end of a shaft also called a valve stem The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a Adding more valves improves the flow of intake and exhaust gases, potentially improving combustion efficiency, power, and performance. It is not practical to simply use two larger valves, for reasons of simple geometry (two smaller intake valves will fit side-by-side on one side of the combustion chamber, whereas a single one cannot be made much larger) and to keep the mass, and therefore inertia, of individual valves as low as possible. Multi-valve geometry also tends to favor the spark plug being located at the top of the combustion chamber, which can be ideal for even flame propagation during combustion. In addition, particularly as the valve begins to open, for equivalent valve/port areas multi-valve geometry allows for increased airflow. Many use double overhead camshafts (DOHC). Overhead camshaft, commonly abbreviated to OHC, Valvetrain configurations place the engine Camshaft within the Cylinder heads above the Overhead camshaft, commonly abbreviated to OHC, Valvetrain configurations place the engine Camshaft within the Cylinder heads above the However this is not always the case: Chevrolet recently showed a 3-valve version of its Generation IV V8 which uses pushrods to actuate forked rockers, and Cummins makes a 4-valve pushrod straight-6 diesel, the Cummins 600. Chevrolet (ˌʃɛvroʊˈleɪ - French origin (also known as Chevy) is a Brand of Automobile, produced by General Motors (GM The LS series is a new design intended as the only V-8 engine utilized in General Motors ' line of RWD cars and trucks An overhead valve (OHV engine, also called pushrod engine or I-head engine is a type of Piston engine that places the Camshaft Cummins Inc ( is a corporation of complementary business units that design manufacture distribute and service diesel and Natural gas Engines and related The straight-6 or inline-6 engine (often abbreviated I6 or L6) is a six cylinder Internal combustion engine with all six cylinders Diesel or Diesel fuel (ˈdiːzəl in general is any Fuel used in Diesel engines The most common is a specific fractional distillate of petroleum The Cummins B Series is a family of Straight-4 and Straight-6 Diesel Truck and industrial Piston engines The B Series

Starting in 1922, many Bugatti engines used three valves per cylinder actuated by a single overhead camshaft (SOHC). Bugatti was founded in Molsheim, France, as a manufacturer of high performance automobiles by Ettore Bugatti, an Italian Overhead camshaft, commonly abbreviated to OHC, Valvetrain configurations place the engine Camshaft within the Cylinder heads above the Nissan has produced the 1988-96 KA24E engine with three valves per cylinder (two intakes, one exhaust) that are also actuated by single overhead camshaft. KA24E The KA24E was a SOHC 12-valve engine produced from July 1988 through January 1996 Mercedes and Ford are currently producing V6 and V8 engines using this configuration. Ford claims an 80% improvement in high rpm breathing without the added cost of a second camshaft per bank of cylinders. The Ford design uses one spark plug per cylinder located in the center, but the Mercedes design uses two spark plugs per cylinder located on opposite sides, leaving the center free to add a direct-to-cylinder fuel injector at a later date. Thus there are many considerations to deciding how many valves an engine should have besides just the added cost versus adding breathing capability.

Some versions of the Honda D-series 4 cylinder engines, and all J-series V6 engines, R-series 4 cylinder engines, and the Chrysler 3.5L V6 engine actuate four valves per cylinder with a single overhead camshaft. () is a Multinational corporation, engine Manufacturer and engineering corporation headquartered in Japan. The Honda D engine is a family of inline 4-cylinder engines used in a variety of compact Honda models most commonly the Honda Civic, CRX, The straight-4 or inline-4 engine (often abbreviated I4 or L4) is a four cylinder Internal combustion engine with all four cylinders The J-series was Honda 's second V6 engine family introduced in 1996 A V6 engine is a V engine with six cylinders mounted on the Crankcase in two banks of three cylinders The Honda R series inline four cylinder engine is new for the 2006 Honda Civic (Non-Si The straight-4 or inline-4 engine (often abbreviated I4 or L4) is a four cylinder Internal combustion engine with all four cylinders The Single overhead cam V6 introduced in 1993 was a major advancement for Chrysler. Overhead camshaft, commonly abbreviated to OHC, Valvetrain configurations place the engine Camshaft within the Cylinder heads above the The V12 engines of many World War II fighter aircraft also used a SOHC configuration with four valves for each cylinder. V12 redirects here For the V12 Training program see V-12 Navy College Training Program. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including

Mitsubishi were the first to market an engine with five valves per cylinder, with the 548 cc 3G81 engine in their Minica Dangan ZZ kei car in 1989. is the sixth largest Automaker in Japan and the seventeenth largest in the world by global unit sales The Mitsubishi 3G8 engine is a range of three cylinder powerplant from Mitsubishi Motors, introduced in the fifth generation of their Mitsubishi Minica The Mitsubishi Minica is a Kei car produced by Mitsubishi Motors for the Japanese domestic market since October 1962 Kei car, K-car, or ( pronounced /keːdʑidoːɕa/ is a Japanese category of small Automobiles, including passenger cars ^[1][2] Volkswagen, Audi, Ferrari and Yamaha/Toyota have subsequently introduced five-valve engines as well. AUDI AG, ( Xetra: NSU commonly known as Audi (aˈʊdi is a German Automobile manufacturer which produces Audi branded cars with headquarters Ferrari SpA is an Italian Sports car manufacturer based in Maranello, Italy ( a Japanese motorized vehicle-producing company (whose HQ is at 2500 Shingai Iwata Shizuoka) is part of the Yamaha Corporation. (pronounced) is a Multinational corporation headquartered in Japan, and is currently the world's largest Automaker. It is arguable if five valve configuration gives any benefit over four valve designs. ^[3]

Maserati made an experimental 2. Maserati is an Italian manufacturer of racing cars and Sports cars established on December 1, 1914, in Bologna. 0 L turbo-V6 engine with six valves per cylinder 1985 (three intakes, three exhaust). ^[4]

Many engines were made with two valves per cylinder, but, starting in the late 80s, a virtual explosion of multi-valve and DOHC engines came to market. As a result, even the most basic engines today usually contain four valves per cylinder, though the two valve configuration is still popular.

Motorcycles

Honda introduced the 4-valve XL250 SOHC single cylinder engine in 1972. () is a Multinational corporation, engine Manufacturer and engineering corporation headquartered in Japan. In 1977 Honda introduced the 3-valve SOHC CB400 twin cylinder models. Yamaha introduced the 5-valve DOHC four cylinder FZ750 in 1984.

In the 1979 to 1992 era, Honda produced a limited number of racing and production motorcycles with 8-valve, V4 engines in 500 and 750cc displacements, the NR series. Honda's NR (New Racing V-four Motorcycle engine series started in 1979 with the 500cc NR500 Grand Prix racer that used oval

References

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