1961 Ferrari 250 TR 61 Spyder Fantuzzi engine

In automotive engineering, an inlet manifold or intake manifold (in

American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lan ...

) is the part of an

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

that supplies the

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...

air The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...

mixture to the

cylinder A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infin ...

s. The word ''

manifold In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point. More precisely, an n-dimensional manifold, or ''n-manifold'' for short, is a topological space with the property that each point has a n ...

'' comes from the Old English word ''manigfeald'' (from the Anglo-Saxon ''manig'' anyand ''feald'' epeatedly and refers to the multiplying of one (pipe) into many.manifold, (adv.) "in the proportion of many to one, by many times". AD1526 ''Oxford English Dictionary'', In contrast, an exhaust manifold collects the

exhaust gas Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an ...

es from multiple cylinders into a smaller number of pipes – often down to one pipe. The primary function of the intake manifold is to ''evenly'' distribute the combustion mixture (or just air in a direct injection engine) to each intake port in the cylinder head(s). Even distribution is important to optimize the efficiency and performance of the engine. It may also serve as a mount for the carburetor, throttle body, fuel injectors and other components of the engine. Due to the downward movement of the

piston A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tig ...

s and the restriction caused by the throttle valve, in a reciprocating

spark ignition A spark-ignition engine (SI engine) is an internal combustion engine, generally a petrol engine, where the combustion process of the air-fuel mixture is ignited by a spark from a spark plug. This is in contrast to compression-ignition engines, ty ...

piston engine A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common featu ...

, a partial

vacuum A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often dis ...

(lower than

atmospheric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...

) exists in the intake manifold. This

manifold vacuum Manifold vacuum, or engine vacuum in an internal combustion engine is the difference in air pressure between the engine's intake manifold and Earth's atmosphere. Manifold vacuum is an effect of a piston's movement on the induction stroke and the ...

can be substantial, and can be used as a source of

automobile ancillary power ] Automobile accessory power can be transferred by several different means. However, it is always ultimately derived from the automobile's engine, internal combustion engine, battery, or other "prime mover" source of energy. The advent of high-po ...

to drive auxiliary systems: power assisted

brake A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction. Background ...

s, emission control devices,

cruise control Cruise control (also known as speed control, cruise command, autocruise, or tempomat) is a system that automatically controls the speed of a motor vehicle. The system is a servomechanism that takes over the throttle of the car to maintain a s ...

ignition Ignition may refer to: Science and technology * Firelighting, the human act of creating a fire for warmth, cooking and other uses * Combustion, an exothermic chemical reaction between a fuel and an oxidant * Fusion ignition, the point at which a ...

advance,

windshield wiper A windscreen wiper, windshield wiper, wiper blade (American English), or simply wiper, is a device used to remove rain, snow, ice, washer fluid, water, or debris from a vehicle's front window. Almost all motor vehicles, including cars, tru ...

power window Power windows or electric windows are automobile windows which can be raised and lowered by pressing a button or switch, as opposed to using a crank handle. History Packard had introduced hydraulic window lifts (power windows) in fall of ...

s, ventilation system valves, etc. This vacuum can also be used to draw any piston blow-by gases from the engine's crankcase. This is known as a positive

crankcase ventilation system A crankcase ventilation system removes unwanted gases from the crankcase of an internal combustion engine. The system usually consists of a tube, a one-way valve and a vacuum source (such as the inlet manifold). The unwanted gases, called "blow- ...

, in which the gases are burned with the fuel/air mixture. The intake manifold has historically been manufactured from

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

or cast iron, but use of composite plastic materials is gaining popularity (e.g. most Chrysler 4-cylinders,

Ford Zetec Ford Motor Company used the Zetec name on a variety of inline 4-cylinder automobile engines. It was coined to replace "Zeta" on a range of 1.6 L to 2.0 L multi-valve engines introduced in 1991 because Ford was threatened with legal acti ...

2.0, Duratec 2.0 and 2.3, and GM's

Ecotec Ecotec (capitalized ECOTEC, from 'Emissions Control Optimization TEChnology') is a General Motors (GM) and Opel Automobile GmbH (Opel) trademark that refers to a series of emissions technologies that were implemented throughout a range of GM engines ...

series).

Turbulence

The carburetor or the fuel injectors spray fuel droplets into the air in the manifold. Due to electrostatic forces and condensation from the boundary layer, some of the fuel will form into pools along the walls of the manifold, and due to surface tension of the fuel, small droplets may combine into larger droplets in the airstream. Both actions are undesirable because they create inconsistencies in the air-fuel ratio. Turbulence in the intake helps to break up fuel droplets, improving the degree of atomization. Better

atomization Atomization refers to breaking bonds in some substance to obtain its constituent atoms in gas phase. By extension, it also means separating something into fine particles, for example: process of breaking bulk liquids into small droplets. Atomizati ...

allows for a more complete burn of all the fuel and helps reduce

engine knock In spark ignition internal combustion engines, knocking (also knock, detonation, spark knock, pinging or pinking) occurs when combustion of some of the air/fuel mixture in the cylinder does not result from propagation of the flame front ignite ...

by enlarging the flame front. To achieve this turbulence it is a common practice to leave the surfaces of the intake and intake ports in the cylinder head rough and unpolished. Only a certain degree of turbulence is useful in the intake. Once the fuel is sufficiently atomized additional turbulence causes unneeded pressure drops and a drop in engine performance.

Volumetric efficiency

The design and orientation of the intake manifold is a major factor in the

volumetric efficiency Volumetric efficiency (VE) in internal combustion engine engineering is defined as the ratio of the mass density of the air-fuel mixture drawn into the cylinder at atmospheric pressure (during the intake stroke) to the mass density of the same volu ...

of an engine. Abrupt contour changes provoke pressure drops, resulting in less air (and/or fuel) entering the combustion chamber; high-performance manifolds have smooth contours and gradual transitions between adjacent segments. Modern intake manifolds usually employ ''runners'', individual tubes extending to each intake port on the cylinder head which emanate from a central volume or "plenum" beneath the carburetor. The purpose of the runner is to take advantage of the

Helmholtz resonance Helmholtz resonance or wind throb is the phenomenon of air resonance in a cavity, such as when one blows across the top of an empty bottle. The name comes from a device created in the 1850s by Hermann von Helmholtz, the ''Helmholtz resonator'', wh ...

property of air. Air flows at considerable speed through the open valve. When the valve closes, the air that has not yet entered the valve still has a lot of momentum and compresses against the valve, creating a pocket of high pressure. This high-pressure air begins to equalize with lower-pressure air in the manifold. Due to the air's inertia, the equalization will tend to oscillate: At first the air in the runner will be at a lower pressure than the manifold. The air in the manifold then tries to equalize back into the runner, and the oscillation repeats. This process occurs at the speed of sound, and in most manifolds travels up and down the runner many times before the valve opens again. The smaller the cross-sectional area of the runner, the higher the pressure changes on resonance for a given airflow. This aspect of Helmholtz resonance reproduces one result of the

Venturi effect The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after its discoverer, the 18th century Italian physicist, Giovanni Battista V ...

. When the piston accelerates downwards, the pressure at the output of the intake runner is reduced. This low pressure pulse runs to the input end, where it is converted into an over-pressure pulse. This pulse travels back through the runner and rams air through the valve. The valve then closes. To harness the full power of the Helmholtz resonance effect, the opening of the intake valve must be timed correctly, otherwise the pulse could have a negative effect. This poses a very difficult problem for engines, since valve timing is dynamic and based on engine speed, whereas the pulse timing is static and dependent on the length of the intake runner and the speed of sound. The traditional solution has been to tune the length of the intake runner for a specific engine speed where maximum performance is desired. However, modern technology has given rise to a number of solutions involving electronically controlled valve timing (for example

Valvetronic The Valvetronic system is a BMW variable valve lift system which, in combination with VANOS, allows infinite adjustment of the intake valve timing and duration. The system claims to improve fuel economy and emissions, and negates the need for ...

), and dynamic intake geometry (see below). As a result of "resonance tuning", some naturally aspirated intake systems operate at a volumetric efficiency above 100%: the air pressure in the combustion chamber before the compression stroke is greater than the atmospheric pressure. In combination with this intake manifold design feature, the exhaust manifold design, as well as the exhaust valve opening time can be so calibrated as to achieve greater evacuation of the cylinder. The exhaust manifolds achieve a vacuum in the cylinder just before the piston reaches top dead center. The opening inlet valve can then—at typical compression ratios—fill 10% of the cylinder before beginning downward travel. Instead of achieving higher pressure in the cylinder, the inlet valve can stay open after the piston reaches bottom dead center while the air still flows in. In some engines the intake runners are straight for minimal resistance. In most engines, however, the runners have curves, some very convoluted to achieve desired runner length. These turns allow for a more compact manifold, with denser packaging of the whole engine, as a result. Also, these "snaked" runners are needed for some variable length/ split runner designs, and allow the size of the

plenum Plenum may refer to: * Plenum chamber, a chamber intended to contain air, gas, or liquid at positive pressure * Plenism, or ''Horror vacui'' (physics) the concept that "nature abhors a vacuum" * Plenum (meeting), a meeting of a deliberative asse ...

to be reduced. In an engine with at least six cylinders the averaged intake flow is nearly constant and the plenum volume can be smaller. To avoid standing waves within the plenum it is made as compact as possible. The intake runners each use a smaller part of the plenum surface than the inlet, which supplies air to the plenum, for aerodynamic reasons. Each runner is placed to have nearly the same distance to the main inlet. Runners whose cylinders fire close after each other, are not placed as neighbors. In 180-degree intake manifolds, originally designed for carburetor V8 engines, the two plane, the split plenum intake manifold separates the intake pulses which the manifold experiences by 180 degrees in the firing order. This minimizes interference of one cylinder's pressure waves with those of another, giving better torque from smooth mid-range flow. Such manifolds may have been originally designed for either two- or four-barrel carburetors, but now are used with both throttle-body and

multi-point fuel injection Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All comp ...

. An example of the latter is the Honda J engine which converts to a single plane manifold around 3500 rpm for greater peak flow and horsepower. Older heat riser manifolds with 'wet runners' for carbureted engines used exhaust gas diversion through the intake manifold to provide vaporizing heat. The amount of exhaust gas flow diversion was controlled by a heat riser valve in the exhaust manifold, and employed a bi-metallic spring which changed tension according to the heat in the manifold. Today's fuel-injected engines do not require such devices.

Variable-length intake manifold

A variable-length intake manifold (VLIM) is an

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combus ...

manifold technology. Four common implementations exist. First, two discrete intake runners with different length are employed, and a butterfly valve can close the short path. Second the intake runners can be bent around a common plenum, and a sliding valve separates them from the plenum with a variable length. Straight high-speed runners can receive plugs, which contain small long runner extensions. The plenum of a 6- or 8-cylinder engine can be parted into halves, with the even firing cylinders in one half and the odd firing cylinders in the other part. Both sub-plenums and the air intake are connected to an Y (sort of main plenum). The air oscillates between both sub-plenums, with a large pressure oscillation there, but a constant pressure at the main plenum. Each runner from a sub plenum to the main plenum can be changed in length. For V engines this can be implemented by parting a single large plenum at high engine speed by means of sliding valves into it when speed is reduced. As the name implies, VLIM can vary the length of the intake tract in order to optimize

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

and

torque In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...

, as well as provide better fuel efficiency. There are two main effects of variable intake geometry: * Venturi effect: At low

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

, the speed of the airflow is increased by directing the air through a path with limited capacity (cross-sectional area). The larger path opens when the load increases so that a greater amount of air can enter the chamber. In

dual overhead cam An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion cha ...

(DOHC) designs, the air paths are often connected to separate intake valves so the shorter path can be excluded by deactivating the intake valve itself. * Pressurization: A tuned intake path can have a light pressurizing effect similar to a low-pressure supercharger due to Helmholtz resonance. However, this effect occurs only over a narrow engine speed range which is directly influenced by intake length. A variable intake can create two or more pressurized "hot spots." When the intake air speed is higher, the dynamic pressure pushing the air (and/or mixture) inside the engine is increased. The dynamic pressure is proportional to the square of the inlet air speed, so by making the passage narrower or longer the speed/dynamic pressure is increased. Many automobile manufacturers use similar technology with different names. Another common term for this technology is variable resonance induction system (VRIS). *

Audi Audi AG () is a German automotive manufacturer of luxury vehicles headquartered in Ingolstadt, Bavaria, Germany. As a subsidiary of its parent company, the Volkswagen Group, Audi produces vehicles in nine production facilities worldwide. Th ...

: 2.8-liter V6 gas engine (1991–98); 3.6- and 4.2-liter V8 engines, 1987–present *

Alfa Romeo Alfa Romeo Automobiles S.p.A. () is an Italian luxury car manufacturer and a subsidiary of Stellantis. The company was founded on 24 June 1910, in Milan, Italy. "Alfa" is an acronym of its founding name, "Anonima Lombarda Fabbrica Automobili." ...

: 2.0 TwinSpark 16v - 155 ps(114 kW) * BMW: DISA and DIVA systems *

Dodge Dodge is an American brand of automobiles and a division of Stellantis, based in Auburn Hills, Michigan. Dodge vehicles have historically included performance cars, and for much of its existence Dodge was Chrysler's mid-priced brand above P ...

: 2.0 A588 – ECH (2001–2005) used in the 2001–2005 model year Dodge Neon R/T *

Ferrari Ferrari S.p.A. (; ) is an Italian luxury sports car manufacturer based in Maranello, Italy. Founded by Enzo Ferrari (1898–1988) in 1939 from the Alfa Romeo racing division as ''Auto Avio Costruzioni'', the company built its first car in ...

: 360 Modena, 550 Maranello *

Ford Ford commonly refers to: * Ford Motor Company, an automobile manufacturer founded by Henry Ford * Ford (crossing), a shallow crossing on a river Ford may also refer to: Ford Motor Company * Henry Ford, founder of the Ford Motor Company * Ford F ...

VIS (Variable-resonance Intake System): on their 2.9-liter 24V Cosworth (BOB) based on the

Ford Cologne V6 engine The original Ford Cologne V6 is a series of 60° cast iron block V6 engines produced continuously by the Ford Motor Company in Cologne, Germany, since 1965. Along with the British Ford Essex V6 engine and the U.S. Buick V6 and GMC Truck V6, t ...

in the later model

Ford Scorpio The Ford Scorpio is an executive car that was produced by Ford Europe from 1985 to 1998. It was the replacement for the European Ford Granada line (although in the UK and Ireland the Scorpio was marketed under the Granada name until 1994). Li ...

* Ford DSI (dual-stage intake): on their

Duratec Duratec is a brand name of the Ford Motor Company used for the company's range of gasoline-powered four-cylinder, five-cylinder and six-cylinder passenger car engines. The original 1993 Duratec V6 engine was designed by Ford and Porsche. Ford ...

2.5- and 3.0-liter V6s and it was also found on the

Yamaha Yamaha may refer to: * Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below). ** Yamaha Music Foundation, an organization estab ...

V6 in the Taurus SHO *Ford: The Ford Modular V8 engines sport either the Intake Manifold Runner Control (IMRC) for 4V engines, or the Charge Motion Control Valve (CMCV) for 3V engines. *Ford: The 2.0L Split Port engine in the Ford Escort and Mercury Tracer feature an Intake Manifold Runner Control variable geometry intake manifold. *

General Motors The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...

: 3.9L LZ8/LZ9 V6, 3.2L LA3 V6, and the 4.3L LF4 V6 in some second generation S10s and Sonomas *

GM Daewoo GM Korea Company ( ko, 한국지엠주식회사) is the South Korean subsidiary of multinational corporation General Motors. GMK is also the third largest automobile manufacturer in South Korea. GM Korea's roots go back to the former Daewoo Mot ...

: DOHC versions of E-TEC II engines *

Holden Holden, formerly known as General Motors-Holden, was an Australian subsidiary company of General Motors. It was an Australian automobile manufacturer, importer, and exporter which sold cars under its own marque in Australia. In its last thre ...

: Alloytec *

Honda is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...

: Integra,

Legend A legend is a Folklore genre, genre of folklore that consists of a narrative featuring human actions, believed or perceived, both by teller and listeners, to have taken place in human history. Narratives in this genre may demonstrate human valu ...

, NSX, Prelude *

Hyundai Hyundai is a South Korean industrial conglomerate ("chaebol"), which was restructured into the following groups: * Hyundai Group, parts of the former conglomerate which have not been divested ** Hyundai Mobis, Korean car parts company ** Hyundai ...

: XG V6 * Isuzu:

Isuzu Rodeo The Isuzu Rodeo is an automotive nameplate that was used by the Japanese automobile manufacturer Isuzu between 1988 and 2004. Isuzu has utilized the "Rodeo" name on two different vehicles—a compact pickup truck sold in Japan—and a midsize S ...

, used in the second generation V6, 3.2L (6VD1) Rodeos *

Jaguar The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus '' Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the th ...

: AJ-V6 *

Lancia Lancia () is an Italian car manufacturer and a subsidiary of FCA Italy S.p.A., which is currently a Stellantis division. The present legal entity of Lancia was formed in January 2007 when its corporate parent reorganised its businesses, but it ...

: VIS *

Mazda , commonly referred to as simply Mazda, is a Japanese multinational automotive manufacturer headquartered in Fuchū, Hiroshima, Japan. In 2015, Mazda produced 1.5 million vehicles for global sales, the majority of which (nearly one m ...

: VICS (variable inertia charging system) is used on the

Mazda FE-DOHC engine The F engine family from Mazda is a mid-sized inline-four piston engine with iron block, alloy head and belt-driven SOHC and DOHC configurations. Introduced in 1983 as the 1.6-litre F6, this engine was found in the Mazda B-Series truck and Mazda ...

and

Mazda B engine The Mazda B-series engine - not to be confused with the Mazda B-Series truck - is a small-sized, iron-block, inline four-cylinder with belt-driven SOHC and DOHC valvetrain ranging in displacement from 1.1 to 1.8 litres. It was used from front-wh ...

family of

straight-4 A straight-four engine (also called an inline-four) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The vast majority of automotive four-cylinder engines use a straight-four layout (with the ...

s, and VRIS (variable resistance induction system) in the

Mazda K engine The Mazda K-series automobile engine is a short stroke 60° 24-valve V6 with belt-driven DOHC and all-aluminium construction. Displacements range from 1.8 L to 2.5 L. They all use a 27-degree DOHC valvetrain with directly actuated hyd ...

family of V6 engines. An updated version of this technology is employed on the new

Mazda Z engine The Mazda Z-series is a smaller gasoline inline-four engine ranging in displacements from 1.3 L to 1.6 L. They are the evolution of the cast-iron block B-engine. The Z-engine has 16-valves operated by dual overhead camshafts, which are in turn ...

, which is also used by Ford as the

. *

Mercedes-Benz Mercedes-Benz (), commonly referred to as Mercedes and sometimes as Benz, is a German luxury and commercial vehicle automotive brand established in 1926. Mercedes-Benz AG (a Mercedes-Benz Group subsidiary established in 2019) is headquartere ...

* MG:

MG ZS 180 The MG ZS was a sports family car that was built by MG Rover from 2001 until 2005. The ZS is essentially a tuned version of the Rover 45 (which was launched in 1999). The 45 in turn is a facelifted version of the Rover 400 which was launched ...

MG ZT The MG ZT is a car which was produced by MG Rover from 2001 to 2005. It was offered in saloon and estate versions, the latter designated as the MG ZT-T. Styling is similar to the Rover 75, upon which it was based, although various modifications, ...

160, 180 and 190 *

Mitsubishi The is a group of autonomous Japanese multinational companies in a variety of industries. Founded by Yatarō Iwasaki in 1870, the Mitsubishi Group historically descended from the Mitsubishi zaibatsu, a unified company which existed from 1870 ...

: Cyclone is used on the 2.0L I4

4G63 The Mitsubishi Sirius or 4G6/4D6 engine is the name of one of Mitsubishi Motors' four series of inline-four automobile engines, along with Astron, Orion, and Saturn. The 4G6 gasoline engines were the favoured performance variant for Mitsubishi. ...

engine family. *

Nissan , trade name, trading as Nissan Motor Corporation and often shortened to Nissan, is a Japanese multinational corporation, multinational Automotive industry, automobile manufacturer headquartered in Nishi-ku, Yokohama, Japan. The company sells ...

: I4, V6, V8 *

Opel Opel Automobile GmbH (), usually shortened to Opel, is a German automobile manufacturer which has been a subsidiary of Stellantis since 16 January 2021. It was owned by the American automaker General Motors from 1929 until 2017 and the PSA Grou ...

(or Vauxhall): TwinPort – modern versions of

Ecotec Family 1 The Family 1 is a straight-four piston engine that was developed by Opel, a former subsidiary of General Motors and now a subsidiary of PSA Group, to replace the Opel cam-in-head engines for use on mid-range cars from Opel/Vauxhall. Origina ...

and Ecotec Family 0 straight-4 engines; a similar technology is used in 3.2 L 54° V6 engine *

Peugeot Peugeot (, , ) is a French brand of automobiles owned by Stellantis. The family business that preceded the current Peugeot companies was founded in 1810, with a steel foundry that soon started making hand tools and kitchen equipment, and the ...

: 2.2 L I4, 3.0 L V6 *

Porsche Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche (; see #Pronunciation, below), is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans, headquartered in Stuttgart, Baden-Württemberg, Germany ...

: VarioRam – 964,

993 Year 993 ( CMXCIII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. Events By place Europe * Spring – The 12-year-old King Otto III gives the Sword of Saints Cosmas and Damian ...

996 Year 996 ( CMXCVI) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events By place Japan * February - Chotoku Incident: Fujiwara no Korechika and Takaie shoot an arrow at Retired Em ...

, Boxster *

Proton A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

: Campro CPS and VIM – Proton Gen-2 CPS and Proton Waja CPS; Proton Campro IAFM – 2008

Proton Saga The Proton Saga is a series of compact and subcompact cars produced by Malaysian automobile manufacturer Proton. Introduced in 1985, the Proton Saga became the first Malaysian car and a major milestone in the Malaysian automotive industry. The ...

1.3 *

Renault Groupe Renault ( , , , also known as the Renault Group in English; legally Renault S.A.) is a French multinational automobile manufacturer established in 1899. The company produces a range of cars and vans, and in the past has manufactured ...

: Clio 2.0RS *

Rover Rover may refer to: People * Constance Rover (1910–2005), English historian * Jolanda de Rover (born 1963), Dutch swimmer * Rover Thomas (c. 1920–1998), Indigenous Australian artist Places * Rover, Arkansas, US * Rover, Missouri, US ...

: Rover 623, Rover 825,

Rover 75 The Rover 75 is an executive car manufactured initially by the Rover Group and later by MG Rover, under the Rover marque and available over a single generation with front-wheel drive in either saloon/sedan or station wagon/estate configura ...

v6,

Rover 45 The Rover 400 Series, and later the Rover 45, are a series of small family cars that were produced by the British manufacturer Rover from 1990 to 2005. The cars were co-developed as part of Rover's collaboration with Honda. The first-generation ...

v6 *

Subaru Legacy The is a mid-size car built by Japanese automobile manufacturer Subaru since 1989. The maker's flagship car, it is unique in its class for offering all-wheel drive as a standard feature, and Subaru's traditional boxer engine. The Legacy was sol ...

1989–1994 JDM EJ20 2.0-liter naturally aspirated DOHC 16-valve flat-4 * Subaru SVX 1992–1997 EG33 3.3-liter naturally aspirated DOHC 24-valve flat-6 *

and

Subaru Impreza The is a compact car that has been manufactured by the Japanese automaker Subaru since 1992. It was introduced as a replacement for the Leone, with the predecessor's EA series engines replaced by the new EJ series. It is now in its sixth gen ...

1999–2001 JDM EJ20 2.0-liter naturally aspirated DOHC 16-valve flat-4 *

Toyota is a Japanese multinational automotive manufacturer headquartered in Toyota City, Aichi, Japan. It was founded by Kiichiro Toyoda and incorporated on . Toyota is one of the largest automobile manufacturers in the world, producing about 10 ...

T-VIS Toyota Variable Induction System, or T-VIS, is a variable intake system designed by Toyota to improve the low-end performance of multi-valve engines. T-VIS is intended to improve the low-end torque of high-performance, four-stroke internal combusti ...

– (Toyota Variable Induction System) used in the early versions of the 3S-GE, 7M-GE, and 4A-GE engines, and ACIS (acoustic control induction system) *

Volkswagen Volkswagen (),English: , . abbreviated as VW (), is a German Automotive industry, motor vehicle manufacturer headquartered in Wolfsburg, Lower Saxony, Germany. Founded in 1937 by the German Labour Front under the Nazi Party and revived into a ...

: 1.6 L I4,

VR6 VR6 engines are V6 piston engines with a narrow angle between the cylinder banks and a single cylinder head covering both banks of cylinders. Volkswagen Group introduced the first VR6 engine in 1991 and VR6 engines currently remain in producti ...

, W8 *

Volvo The Volvo Group ( sv, Volvokoncernen; legally Aktiebolaget Volvo, shortened to AB Volvo, stylized as VOLVO) is a Swedish multinational manufacturing corporation headquartered in Gothenburg. While its core activity is the production, distributio ...

: VVIS (Volvo variable induction system) – Volvo B5254S and B5204S engines as found on the

Volvo 850 The Volvo 850 is a compact executive car that was produced by the Swedish manufacturer Volvo Cars from 1991 until 1996. Designed by Jan Wilsgaard, the car was introduced in a saloon body style; an estate style was introduced in 1993. The Volv ...

vehicles. Longer inlet ducts used between 1500 and 4100 rpm at 80% load or higher.Volvoclub UK: 850GLT Engine Info
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References

{{Automotive engine Engine technology Auto parts

Turbulence

Volumetric efficiency

Variable-length intake manifold

See also

References