V6 engine
A V6 engine is a V engine with six cylinders mounted on the crankcase in two banks of three cylinders, usually set at either a right angleor an acute angle to each other, with all six pistons driving a common crankshaft. It is the second most common engine configuration in modern cars after the inline four.
The V6 is one of the most compact engine configurations, shorter than the inline-4 and in many designs narrower than the V8. Owing to its compact length, the V6 lends itself well to the widely-used transverse engine front-wheel drive layout. It is becoming more common as the space allowed for engines in modern cars is reduced at the same time as power requirements increase, and has largely replaced theinline-6, which is too long to fit in many modern engine compartments. Although it is more complicated and, in some cases, not as smooth as the inline-6, the V6 is more rigid for a given weight, more compact and less prone to torsional vibrations in the crankshaft for a given displacement. The V6 engine has become widely adopted for medium-sized cars, often as an optional engine where an inline-4 is standard, or as a base engine where a V8 is a higher-cost performance option.
Some of the first V6-cars were built in 1905 by Marmon. Marmon was something of a V-Specialist which began with V2-engines, then built V4's and V6's, later V8's and in the 1930s Marmon was one of the few car-makers of the world which ever built a V16 car.
Another V6-car was designed in 1918 by Leo Goosen for Buick Chief Engineer Walter L. Marr. Only one prototype Buick V6 car was built in 1918 and was long used by the Marr family.
The first series production V6 was introduced by Lancia in 1950 with the Lancia Aurelia. Other manufacturers took note and soon other V6 engines were in use. In 1959, GM introduced a heavy-duty 305 in3 (5L) 60° V6 for use in their pickup trucks and Suburbans, an engine design that was later enlarged to 478 in3 (7.8 L) for heavy truck and bus use.
The most efficient cylinder bank angle for a V6 is 60 degrees, minimizing size and vibration. While 60° V6 engines are not as well balanced as inline-6and flat-6 engines, modern techniques for designing and mounting engines have largely disguised their vibrations. Unlike most other angles, 60-degree V6 engines can be made acceptably smooth without the need for balance shafts. When Lancia pioneered the 60° V6 in 1950, a 6-throw crankshaft was used to give equal firing intervals of 120°.
90° V6 engines are also produced, usually so they can use the same production-line tooling set up to produce V8 engines (which normally have a 90° V angle). Although it is relatively easy to derive a 90° V6 from an existing V8 design by simply cutting two cylinders off the engine, this tends to make it wider and more vibration-prone than a 60° V6. The design was first used by Buickwhen it introduced its 198 CID Fireball V6 as the standard engine in the 1962 Special.
V8 Engine
A V8 engine is a V engine with eight cylinders mounted on the crankcase in two banks of four cylinders, in most cases set at a right angle to each other but sometimes at a narrower angle, with all eight pistons driving a common crankshaft.
In its simplest form, it is basically two straight-4 engines sharing a common crankshaft. However, this simple configuration, with a single-plane crankshaft, has the same secondary dynamic imbalance problems as two straight-4s, resulting in vibrations in large engine displacements. As a result, since the 1920s most V8s have used the somewhat more complex crossplane crankshaft with heavy counterweights to eliminate the vibrations. This results in an engine which is smoother than a V6, while being considerably less expensive than a V12 engine. Most racing V8s continue to use the single plane crankshaft because it allows faster acceleration and more efficient exhaust system designs.
The V8 with a crossplane crankshaft (see below) is a common configuration for large automobile engines. V8 engines are rarely less than 3.0 L (183 cu in) in displacement and in automobile use have exceeded 8.2 L (500 cu in) in production vehicles. Industrial and marine V8 engines can be much larger.V8s are generally only standard on more powerful muscle cars, pony cars, sports cars, luxury cars, pickup trucks, and SUVs. However they are often options in vehicles which have a V6 or straight-6 as standard engine. In some cases, V6 engines were derived from V8 designs by removing two cylinders maintaining the V-angle so they can be built on the same assembly lines as the V8s and installed in the same engine compartments with few modifications. Some of these employed offset crankpins driving connecting rod pairs, enabling a regular firing sequence.
The most prevalent V angle for a V8 is 90°. This configuration features a wide, low engine with optimal firing and vibration characteristics. Many V6 andV10 engine configurations are derived from production V8 designs, they often use the 90° angle; however, balance shafts are incorporated to reduce vibration or more complex cranks to even the firing cycle. V8s can use different angles.
First Automobile Works introduced the first V8 engine in Asia in 1959, used in FAW Hongqi luxury automobiles.
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HQ430
V12 Engine
A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft.
Since each cylinder bank is essentially a straight-6, this configuration has perfect primary and secondary balance no matter which V angle is used and therefore needs no balance shafts. A V12 with two banks of six cylinders angled at 60°, 120° or 180° (with the latter configuration usually referred to as aflat-12) from each other has even firing with power pulses delivered twice as often per revolution as a straight-6. This allows for great refinement in a luxury car. In a racing car, the rotating parts can be made much lighter and thus more responsive, since there is no need to use counterweights on the crankshaft as is needed in a 90° V8 and less need for the inertial mass in a flywheel to smooth out the power delivery. In a large displacement, heavy-duty engine, a V12 can run slower than smaller engines, prolonging engine life.
The first V12 engines were used in aircraft. By the end of World War I, V12s were popular in the newest and largest fighters and bombers and were produced by companies such as Renault and Sunbeam. Many Zeppelins had 12-cylinder engines from German manufacturers Maybach and Daimler. Various U.S. companies produced the Liberty L-12; the Curtiss NC Flying boats, including the four V12 engine powered NC-4, the first aircraft to make atransatlantic flight.The Rolls-Royce Merlin V12 powered the Hawker Hurricane and Supermarine Spitfire fighters that played a vital role in Britain's victory in the Battle of Britain. The long, narrow configuration of the V12 contributed to good aerodynamics, while its smoothness allowed its use with relatively light and fragile airframes. In automobiles, V12 engines have not been common due to their complexity and cost. They are used almost exclusively in expensive sports cars and luxury cars because of their power, smoother operation, and distinctive sound.
V12 engines used to be common in Formula One and endurance racing. From 1965 to 1980,Ferrari, Weslake, Honda, BRM, Maserati, Matra, Delahaye, Peugeot, Delage, Alfa Romeo,Lamborghini and Tecno used 12-cylinder engines in Formula One, either V12 or Flat-12, but theFord (Cosworth) V8 had a slightly better power-to-weight ratio and less fuel consumption, thus it was more successful despite being less powerful than the best V12s
V12 is a common configuration for large diesel engines; most are available with differing numbers of cylinders in V configuration to offer a range of power ratings. Many diesel locomotives have V12 engines. Examples include the 3,200 hp (2.39 MW) 12-710 from Electro-Motive Diesel and the 4,400 hp (3.28 MW) GEVO-12 from GE Transportation.
Large V12 engines are also common in ships. For example Wärtsilä, offers V12 engines with various cylinder bore diameters between 26 and 50 centimetres (10 and 20 in) with power output ranging from 4,080 kW (5,470 hp) to 14,400 kW (19,300 hp). These engines are commonly used especially in cruise ships, which may have up to six such main engines.[7] In the past the largest medium-speed diesel engine in the world, Wärtsilä 64, was also offered in V configuration, and a single 12V64 prototype with an output of 23,280 kW (31,220 hp) was produced for an experimental power plant in the late 1990s.
V16 Engine
A V16 engine is a V engine with 16 cylinders. Engines of this number of cylinders are uncommon in automotive use.
A V16 engine is perfectly balanced regardless of the V angle without requiring counter-rotating balancing shafts which are necessary to balanceStraight-4 and odd number of cylinder inline engines or counterweighted crankshaft like the 90° V8. In addition angles of 45° and 135° vees give an impulse every 45°, so are optimal solutions, for even-firing and non-split bearing crankshaft journals.
V16 engines are rarely used in automobiles because V8s or V12s of the same displacement produce just as much power, but are much less expensive to manufacture and maintain. The few V16s that have been produced were used in high-end luxury and high-performance automobilesdue to their smoothness (low vibration).
Today, the most common applications for V16 engines are railroad locomotives, marine craft, and stationary power generators.
The first known use of a V16 in auto racing was by Harry Miller installing a custom-built V16 that he had built for a Cord "supercar" he had been working on into a chassis that he had built for the 1931 Indianapolis 500 driven by Shorty Cantlon. The car was competitive, charging from 26th on the grid to 3rd, but was slowed by unreliability, further exacerbated by having to change all sixteen spark plugs. Bryan Saulpaugh qualified the car third for the 1932 Indianapolis 500, but the car suffered a broken oil line on lap 55 and their race was over. Shortly after the race the V16 was removed and replaced with a conventional Miller four-cylinder. The car was re-assembled and rebuilt with an exact replica V16 in 1993.
V24 Engine
A V24 engine is a V engine with 24 cylinders, suitable only for very large trucks or locomotives.
Unlike smaller V16 and V20 engines, very few V24s were originally designed with 24 cylinders. The majority of these engines are formed by coupling multiple smaller engines together. For example, a very large V24, the AS.6, engine was built by Fiat in the early 1930s as a powerplant for the competition aeroplane Macchi M.C.72. This engine was in reality formed by mounting two Fiat AS.5 V12s, one behind the other, obtaining a total displacement of over 50 litres (3,051 cu in) and a power output of about 3,100 horsepower (2,310 kW). The two units remained separated (they could be started separately) but the output shaft was shared. Between the units sat the gearbox that was used to reduce the propeller speed, and the final output shaft ran between the cylinder banks of the front engine to reach the nose of the aeroplane.
The Detroit Diesel 24V-71 is an example of a modern, two-stroke V24 Diesel engine. It is capable of producing 1,800 horsepower from a 27.9 liter displacement.
W12 engine
A W12 engine is a twelve cylinder piston internal combustion engine in a W configuration. W12 engines are manufactured in two distinct configurations. One configuration uses four rows of three cylinders merged into two 'cylinder banks' (two narrow-angle VR6 engine blocks), coupled to a commoncrankshaft - as in the Volkswagen Group W12. The other uses three banks of four cylinders coupled to a common crankshaft- as in the Napier Lion.The Napier Lion was a broad arrow-style W12 engine produced by Napier at Acton, West London, from 1917 to the late 1930s. This mostly alloy engine had a capacity of 24 litres (1,465 cu in) and produced from 450 to 900 horsepower (336 to 671 kW; 456 to 912 PS). It was used in many racing cars by John Cobb and Malcolm Campbell, racing aircraft such as the Supermarine S.5Schneider Cup winner, and speed boats such as Hubert Scott-Paine's Miss Britain III. This configuration had three separate four-cylinder banks, each at 60 degrees offset from one another, as opposed to the "double V" layout used by Volkswagen-Audi (VAG). Sunbeam tried the similar Kaffir, based on their Arab V8 engine.
At the 2001 Tokyo Motor Show, Volkswagen Group showcased a prototype Volkswagen Nardo W12 Coupé, a mid-engined, rear-wheel drive supercarpowered by a 6.0 litre W12 engine, producing 600 horsepower (447 kW; 608 PS). A week before, the W12 Coupe broke the 24 hour world endurance record. A total distance of 7,085.7 kilometres (4,402.8 mi) was covered at an average speed of 295.24 kilometres per hour (183.45 mph), breaking the old record by 12 kilometres per hour (7.5 mph). Production of the W12 Coupé was considered, but was subsequently cancelled.
Volkswagen Group currently produces W12 engines by forming two imaginary narrow-angle 15° VR6 engines at an angle of 72°.The narrow angle of each set of cylinders allows just two overhead camshafts to drive each pair of banks, so just four are needed in total. Note that this design differs from the W18 engine that Volkswagen Group produced for its Bugatti concept cars of 1998 and 1999. Due to this distinction, the Volkswagen Group's W12 engine is sometimes described as a "WR12".
In the late 1980s, two W12 engines were designed and built for use in Formula One. In France, Guy Negre produced the MGN which had three banks of four cylinders offset so that each crankpin accommodated three connecting rods side-by-side. The MGN also had a novel system of cylindrical rotary valves located at the top of the combustion chambers, making the engine notably compact. The engine was tested in an AGS Formula One car, and in a Norma sports car, but never raced.
Four Stroke Engine
There are two common types of four-stroke engines. They are closely related to each other, but have major differences in design and behavior. The earliest of these to be developed is the Otto cycle engine developed in 1876 by Nikolaus August Otto in Cologne, Germany,after the operation principle described by Alphonse Beau de Rochas in 1861. This engine is most often referred to as a petrol engine or gasoline engine, after the fuel that powers it. The second type of four-stroke engine is the Diesel engine developed in 1893 by Rudolph Diesel, also of Germany. Diesel created his engine to maximize efficiency, which the Otto engine lacked. There are several major differences between the Otto cycle engine and the four-cycle diesel engine. The diesel engine is made in both a two-cycle and a four-cycle version. Otto's company, Deutz AG, now primarily produces diesel engines.
The Otto cycle is named after the 1876 engine of Nikolaus A. Otto, who built a successful four-cycle engine based on the work of Jean Joseph Etienne Lenoir. It was the third engine type that Otto developed. It used a sliding flame gateway for ignition of its fuel—a mixture of illuminating gas and air. After 1884, Otto also developed the magneto to create an electrical spark for ignition, which had been unreliable on the Lenoir engine.
The thermodynamics analysis of the actual four-stroke or two-stroke cycles is not a simple task. However, the analysis can be simplified significantly if air standard assumptions are utilized. The resulting cycle, which closely resembles the actual operating conditions, is the Otto cycle.
Jet Engine
A jet engine is a reaction engine that discharges a fast moving jet which generates thrust by jet propulsion in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, and pulse jets. In general, most jet engines are internal combustion engines but non-combusting forms also exist.
In common parlance, the term jet engine loosely refers to an internal combustion airbreathing jet engine (a duct engine). These typically consist of an engine with a rotary (rotating) air compressor powered by a turbine ("Brayton cycle"), with the leftover power providing thrust via a propelling nozzle. These types of jet engines are primarily used by jet aircraft for long distance travel. Early jet aircraft used turbojet engines which were relatively inefficient for subsonic flight. Modern subsonic jet aircraft usually use high-bypass turbofan engines which offer high speed with fuel efficiency comparable (over long distances) to piston and propeller aeroengines.
Jet engines can be dated back to the invention of the aeolipile before the first century AD. This device used steam power directed through two nozzles to cause a sphere to spin rapidly on its axis. So far as is known, it was not used for supplying mechanical power, and the potential practical applications of this invention were not recognized. It was simply considered a curiosity.
Jet propulsion only took off, literally and figuratively, with the invention of the gunpowder-powered rocket by the Chinese in the 13th century as a type of fireworks, and gradually progressed to propel formidable weaponry. However, although very powerful, at reasonable flight speeds rockets are very inefficient and so jet propulsion technology stalled for hundreds of years.
Jet engines are usually used as aircraft engines for jet aircraft. They are also used for cruise missiles and unmanned aerial vehicles.
In the form of rocket engines they are used for fireworks, model rocketry, spaceflight, and military missiles.
Jet engines have also been used to propel high speed cars, particularly drag racers, with the all-time record held by a rocket car. A turbofan powered carThrustSSC currently holds the land speed record.
Jet engine designs are frequently modified for non-aircraft applications, as industrial gas turbines. These are used in electrical power generation, for powering water, natural gas, or oil pumps, and providing propulsion for ships and locomotives. Industrial gas turbines can create up to 50,000 shaft horsepower. Many of these engines are derived from older military turbojets such as the Pratt & Whitney J57 and J75 models. There is also a derivative of the P&W JT8D low-bypass turbofan that creates up to 35,000 HP.
There are a large number of different types of jet engines, all of which achieve forward thrust from the principle of jet propulsion.
Turbojet
A turbojet engine is a gas turbine engine that works by compressing air with an inlet and a compressor (axial, centrifugal, or both), mixing fuel with the compressed air, burning the mixture in the combustor, and then passing the hot, high pressure air through a turbine and a nozzle. The compressor is powered by the turbine, which extracts energy from the expanding gas passing through it. The engine converts internal energy in the fuel to kinetic energy in the exhaust, producing thrust. All the air ingested by the inlet is passed through the compressor, combustor, and turbine, unlike the turbofanengine described below.
There are two general types of turbofan engines, low bypass and high bypass. Low bypass turbofans have a bypass ratio of around 2:1 or less, meaning that for each kilogram of air that passes through the core of the engine, two kilograms or less of air bypass the core. Low bypass turbofans often used a mixed exhaust nozzle meaning that the bypassed flow and the core flow exit from the same nozzle. High bypass turbofans have larger bypass ratios, sometimes on the order of 5:1 or 6:1. These turbofans can produce much more thrust than low bypass turbofans or turbojets because of the large mass of air that the fan can accelerate, and are often more fuel efficient than low bypass turbofans or turbojets.
Turboprop and turboshaft
Turboprop engines are jet engine derivatives, still gas turbines, that extract work from the hot-exhaust jet to turn a rotating shaft, which is then used to produce thrust by some other means. While not strictly jet engines in that they rely on an auxiliary mechanism to produce thrust, turboprops are very similar to other turbine-based jet engines, and are often described as such.
In turboprop engines, a portion of the engines' thrust is produced by spinning a propeller, rather than relying solely on high-speed jet exhaust. As their jet thrust is augmented by a propeller, turboprops are occasionally referred to as a type of hybrid jet engine. While many turboprops generate the majority of their thrust with the propeller, the hot-jet exhaust is an important design point, and maximum thrust is obtained by matching thrust contributions of the propeller to the hot jet.[14] Turboprops generally have better performance than turbojets or turbofans at low speeds where propeller efficiency is high, but become increasingly noisy and inefficient at high speeds.
Turboshaft engines are very similar to turboprops, differing in that nearly all energy in the exhaust is extracted to spin the rotating shaft, which is used to power machinery rather than a propeller, they therefore generate little to no jet thrust and are often used to power helicopters.
Propfan
Ram powered jet engines are airbreathing engines similar to gas turbine engines and they both follow the Brayton cycle.
Gas turbine and ram powered engines differ, however, in how they compress the incoming airflow. Whereas gas turbine engines use axial or centrifugal compressors to compress incoming air, ram engines rely only on air compressed through the inlet or diffuser. Ram powered engines are considered the most simple type of air breathing jet engine because they can contain no moving parts.
Ramjet
ScramjetRamjets are the most basic type of ram powered jet engines. They consist of three sections; an inlet to compressed oncoming air, a combustor to inject and combust fuel, and a nozzle expel the hot gases and produce thrust. Ramjets require a relatively high speed to efficiently compress the oncoming air, so ramjets cannot operate at a standstill and they are most efficient at supersonic speeds. A key trait of ramjet engines is that combustion is done at subsonic speeds. The supersonic oncoming air is dramatically slowed through the inlet, where it is then combusted at the much slower, subsonic, speeds.The faster the oncoming air is, however, the less efficient it becomes to slow it to subsonic speeds. Therefore ramjet engines are limited to approximately Mach 5..Very few scramjet engines have ever been built and flown. In May 2010 the Boeing X-51 set the endurance record for the longest scramjet burn at over 200 seconds.Scramjets are mechanically very similar to ramjets. Like a ramjet, they consist of an inlet, a combustor, and a nozzle. The primary difference between ramjets and scramjets is that scramjets do not slow the oncoming airflow to subsonic speeds for combustion, they use supersonic combustion instead. The name "scramjet" comes from "supersonic combusting ramjet." Since scramjets use supersonic combustion they can operate at speeds above Mach 6 where traditional ramjets are too inefficient. Another difference between ramjets and scramjets comes from how each type of engine compresses the oncoming air flow: while the inlet provides most of the compression for ramjets, the high speeds at which scramjets operate allow them to take advantage of the compression generated by shock waves, primarily oblique shocks.
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