Stall (engine)

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A stall is the slowing or stopping of a process, and, in the case of an engine, refers to a sudden stopping of the engine turning, [1] usually brought about accidentally.

Contents

It is commonly applied to the phenomenon whereby an engine abruptly ceases operating and stops turning. It might be due to not getting enough air, energy, fuel, or electric spark, fuel starvation, a mechanical failure, or in response to a sudden increase in engine load. [1] [2] This increase in engine load is common in vehicles with a manual transmission when the clutch is released too suddenly. [3]

The ways in which a car can stall are usually down to the driver, especially with a manual transmission. For instance, if a driver takes their foot off the clutch too quickly while stationary then the car will stall; taking the foot off the clutch slowly will stop this from happening. Stalling also happens when the driver forgets to depress the clutch and/or change to neutral while coming to a stop. [3] Stalling can be dangerous, especially in heavy traffic. [1]

A car fitted with an automatic transmission could also have its engine stalled when the vehicle is travelling in the opposite direction to the selected gear. [4] For example, if the selector is in the 'D' position and the car is moving backwards, (on a steep enough hill to overcome the torque from the torque converter) the engine will stall, because the engine is forced to turn in the opposite direction to what it is actually doing. This is because, hypothetically, if the car is rolling backward fast enough, the force from the rotating wheels will be transmitted backward through the transmission and act as a sudden load on the engine.

Digital electronics fuel injection and ECU ignition systems have greatly reduced stalling in modern engines. [5]

Anti-stall systems

An anti-stall system is an automatically operated electronic clutch control device preventing the stalling of an engine [6] by engaging the clutch when the ECU detects that the engine revs are too low. They are used in motorsports such as Formula One and Indy Car, [7] but not Formula 2 and Formula 3, and may be regarded as a driver aid [8] [9] since it usually keeps the engine running even if the car stops on track while in gear. It is also sometimes used on production cars. [10]

See also

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<span class="mw-page-title-main">Automatic transmission</span> Type of motor vehicle transmission that automatically changes gear ratio as the vehicle moves

An automatic transmission is a multi-speed transmission used in motor vehicles that does not require any input from the driver to change forward gears under normal driving conditions. Vehicles with internal combustion engines, unlike electric vehicles, require the engine to operate in a narrow range of rates of rotation, requiring a gearbox, operated manually or automatically, to drive the wheels over a wide range of speeds.

<span class="mw-page-title-main">Torque converter</span> Fluid coupling that transfers rotating power from a prime mover to a rotating driven load

A torque converter is a device, usually implemented as a type of fluid coupling, that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the torque converter connects the prime mover to the automatic gear train, which then drives the load. It is thus usually located between the engine's flexplate and the transmission. The equivalent device in a manual transmission is the mechanical clutch.

<span class="mw-page-title-main">Transmission (mechanical device)</span> Drivetrain transmitting propulsion power

A transmission is a mechanical device which uses a gear set—two or more gears working together—to change the speed, direction of rotation, or torque multiplication/reduction in a machine.

<span class="mw-page-title-main">Manual transmission</span> Motor vehicle manual gearbox; stick shift

A manual transmission (MT), also known as manual gearbox, standard transmission, or stick shift, is a multi-speed motor vehicle transmission system where gear changes require the driver to manually select the gears by operating a gear stick and clutch.

A semi-automatic transmission is a multiple-speed transmission where part of its operation is automated, but the driver's input is still required to launch the vehicle from a standstill and to manually change gears. Semi-automatic transmissions were almost exclusively used in motorcycles and are based on conventional manual transmissions or sequential manual transmissions, but use an automatic clutch system. But some semi-automatic transmissions have also been based on standard hydraulic automatic transmissions with torque converters and planetary gearsets.

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<span class="mw-page-title-main">Launch control (automotive)</span> Electronic aid for drivers of racing cars

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A centrifugal clutch is an automatic clutch that uses centrifugal force to operate. The output shaft is disengaged at lower rotational speed and engages as the output increases to a certain speed. It is often used in mopeds, underbones, lawn mowers, go-karts, chainsaws, mini bikes, and some paramotors and boats to keep the engine from stalling when the output shaft is slowed or stopped abruptly, and to remove load when starting and idling. It has been superseded for automobile applications by the fluid coupling, torque converter and automated manual transmissions.

Clutch control refers to the act of controlling the speed of a vehicle with a manual transmission by partially engaging the clutch plate, using the clutch pedal instead of the accelerator pedal. The purpose of a clutch is in part to allow such control; in particular, a clutch provides transfer of torque between shafts spinning at different speeds. In the extreme, clutch control is used in performance driving, such as starting from a dead stop with the engine producing maximum torque at high RPM.

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Synchronized downshift rev-matching system is a technology invented by Nissan for use on the Nissan 370Z. In combination with the Electronic Control Unit (ECU) and various sensors, the engine electronically blips the throttle for the driver during both downshifts and upshifts to allow for better and smoother shifting, and improved handling.

<span class="mw-page-title-main">Motorcycle transmission</span> Transmission for motorcycle applications

A motorcycle transmission is a transmission created specifically for motorcycle applications. They may also be found in use on other light vehicles such as motor tricycles and quadbikes, go-karts, offroad buggies, auto rickshaws, mowers, and other utility vehicles, microcars, and even some superlight racing cars.

An idle air control actuator or idle air control valve is a device commonly used in fuel-injected vehicles to control the engine's idling rotational speed (RPM). In carburetted vehicles a similar device known as an idle speed control actuator is used.

<span class="mw-page-title-main">Car controls</span> Car parts used to control the vehicle

Car controls are the components in automobiles and other powered road vehicles, such as trucks and buses, used for driving and parking.

<span class="mw-page-title-main">Gliding (vehicle)</span> Being more fuel efficient by letting go of the gas pedal when moving

Gliding is an energy-efficient driving mode achieved by turning off the internal combustion engine while the vehicle is still moving in order to save fuel. This is differentiated from coasting, which means running the vehicle in idle mode by disengaging the engine from the wheels, either by disengaging the clutch or setting the transmission or gearbox to neutral position. Gliding and coasting use the accelerated kinetic energy reserve stored in the vehicles mass, i.e. inertia, to keep the vehicle moving. This energy, however, is being lost due to forces that resist movement, such as air-drag, rolling resistance and gravity. The functionality, being an integral concept of hybrid electric vehicles, is performed automatically by the engine controller. For vehicles with a conventional internal combustion engine, coasting can be performed manually; gliding requires having a gear box. Manual gliding or coasting is illegal in some states. An extra button to stop the engine was shown in 1979 on International Motor Show Germany, but never became a feature in mass production of any vehicle. In 1980 research was made on the IRVW II. A so-called eClutch uses an actuator to disengage the clutch when the driver releases the accelerator.

References

  1. 1 2 3 Schultz, Mort (March 1979), "How to stop stalling", Popular Mechanics, pp. 128–130, ISSN   0032-4558, OCLC   3643271 , retrieved 13 November 2014
  2. Hillier, Victor A. W. (1990), Fundamentals of Motor Vehicle Technology (4th ed.), Cheltenham: Nelson Thornes, p. 223, ISBN   9780748705313, OCLC   46761850 , retrieved 13 November 2014
  3. 1 2 Wardlaw, Christian (11 August 2014), "Get the most out of your car: How to drive a manual transmission", Daily News, New York, archived from the original on 13 August 2014, retrieved 14 November 2014
  4. Roth, Dan (20 August 2009), "What Would Happen If You Put Your Car In Reverse While Driving?", AOL, archived from the original on 26 August 2009, retrieved 14 November 2014
  5. Hatch, Steve V. (2012), Computerized engine controls (9th ed.), Clifton Park: Delmar, Cengage Learning, p. 529, ISBN   9781111134907, OCLC   676729348 , retrieved 13 November 2014
  6. What Is Anti-Stall On An F1 Car? | F1 Explained
  7. New-to-IZOD IndyCar Series anti-stall system is available
  8. Todt proposes radical new ban on "driver aids" in Formula 1 | RaceFans
  9. F1: Little support for proposed ban on anti-stall and 'driver aids' | RaceFans
  10. Ny Mercedes Vision