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Three-stage VTEC
Three-stage VTEC is a multi-stage implementation of Honda's VTEC and VTEC-E (colloquially known as dual VTEC) technology, implemented in some of the company's D series engines from 1995 to the present day, allowing the engine to achieve both fuel efficiency and power. VTEC-E (for "Efficiency") is a form of VTEC that closes off one intake valve at low RPMs to give good economy at low power levels, while "VTEC" is a mode that allows for greater power at high RPMs, while giving relatively efficient performance at "normal" operating speeds. "Three-stage VTEC" gives both types in one engine, at the cost of greater complexity and expense. Stage 1 – 12-valve VTEC-E VTEC-E (economy) was designed to achieve better fuel economy, at the cost of performance. The engine operates in "12-valve mode", where one intake valve per cylinder in the 16-valve engine remains mostly closed to attain lean burn. The lean burn mode gets the air to fuel ratio above the 14.7:1 stoichiometric ratio and thus ena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VTEC
VTEC (described as ''Variable Valve Timing & Lift Electronic Control'', but stands for ''Valve Timing Electronically Controlled'') is a system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine, resulting in higher performance at high RPM, and lower fuel consumption at low RPM. The VTEC system uses two (or occasionally three) camshaft profiles and hydraulically selects between profiles. It was invented by Honda engineer Ikuo Kajitani. It is distinctly different from standard VVT (variable valve timing) systems which change only the valve timings and do not change the camshaft profile or valve lift in any way. Context and description Japan levies a tax based on engine displacement, and Japanese auto manufacturers have correspondingly focused their research and development efforts toward improving the performance of their smaller engine designs. One method for increasing performance into a static displacement includes forced i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honda D Engine
The Honda D-series Straight-four engine, inline-four cylinder engine is used in a variety of compact models, most commonly the Honda Civic, Honda CRX, CRX, Honda Logo, Logo, Honda Stream, Stream, and first-generation Honda Integra, Integra. Engine displacement ranges between 1.2 and 1.7 liters. The D series engine is either SOHC or DOHC, and might include VTEC variable valve lift. Power ranges from in the Logo to in the Japanese market (JDM) Civic. D-series production commenced in 1983 (for the 1984 model year) and ended in 2005. D-series engine technology culminated with production of the D15B three-stage VTEC (D15Z7) which was available in markets outside of the United States. Earlier versions of this engine also used a single port fuel delivery system called PGM-CARB, signifying that the carburetor was computer controlled. D12 series engines (1.2 liter) D12A * Found in: ** 1986-1988 Honda City GG (Japanese Market) *** Displacement: 1237 cc (75.5 Cubic inch, cu in) *** Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuel Efficiency
Fuel efficiency (or fuel economy) is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical energy, chemical potential energy contained in a carrier (fuel) into kinetic energy or Mechanical work, work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile. Non-transportation applications, such as Industrial sector, industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process. In the context of transport, fuel economy is the energy efficiency in transportation, energy efficiency of a particular vehicle, given as a ratio of distance traveled per unit of Motor fuel, fuel consumed. It is dependent on several factors including engine efficiency, transmission (mechanics), transmission design, and tire design. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intake Valve
A poppet valve (also sometimes called mushroom valve) is a valve typically used to control the timing and quantity of petrol (gas) or vapour flow into or out of an engine, but with many other applications. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usually a disk shape on the end of a shaft known as a valve stem. The working end of this plug, the valve face, is typically ground at a 45° bevel to seal against a corresponding valve seat ground into the rim of the chamber being sealed. The shaft travels through a valve guide to maintain its alignment. A pressure differential on either side of the valve can assist or impair its performance. In exhaust applications higher pressure against the valve helps to seal it, and in intake applications lower pressure helps open it. Etymology The word poppet shares etymology with "puppet": it is from the Middle English ''popet'' ("youth" or "doll"), from Middle French ''poupette'', whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylinder (engine)
In an engine, the cylinder is the space in which a piston travels. The inner surface of the cylinder is formed from either a thin metallic liner (also called "sleeve") or a surface coating applied to the engine block. A piston is seated inside each cylinder by several metal piston rings, which also provide seals for compression and the lubricating oil. The piston rings do not actually touch the cylinder walls, instead they ride on a thin layer of lubricating oil. Steam engines The cylinder in a steam engine is made pressure-tight with end covers and a piston; a valve distributes the steam to the ends of the cylinder. Cylinders were cast in cast iron and later in steel. The cylinder casting can include other features such as valve ports and mounting feet. Internal combustion engines The cylinder is the space through which the piston travels, propelled by the energy generated from the combustion of the air/fuel mixture in the combustion chamber. In an air-cooled e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lean Burn
Lean-burn refers to the burning of fuel with an excess of air in an internal combustion engine. In lean-burn engines the air–fuel ratio may be as lean as 65:1 (by mass). The air:fuel ratio needed to stoichiometry, stoichiometrically combust gasoline, by contrast, is 14.64:1. The excess of air in a lean-burn engine emits far less unburned hydrocarbon, hydrocarbons. High air–fuel ratios can also be used to reduce losses caused by other engine power management systems such as throttling losses. Principle A lean-burn mode is a way to reduce throttling losses. An engine in a typical vehicle is sized for providing the power desired for acceleration, but must operate well below that point in normal steady-speed operation. Ordinarily, the power is cut by partially closing a throttle. However, the extra work done in pulling air through the throttle reduces efficiency. If the fuel/air ratio is reduced, then lower power can be achieved with the throttle closer to fully open, and the effi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air To Fuel Ratio
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. Most organisms use oxygen for respiration; lightning and bacteria perform nitrogen fixation which produces ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, solar wind, and cosmic rays and thus protects the organisms from genetic damage. The current composition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stoichiometric
Stoichiometry () is the relationships between the masses of reactants and products before, during, and following chemical reactions. Stoichiometry is based on the law of conservation of mass; the total mass of reactants must equal the total mass of products, so the relationship between reactants and products must form a ratio of positive integers. This means that if the amounts of the separate reactants are known, then the amount of the product can be calculated. Conversely, if one reactant has a known quantity and the quantity of the products can be empirically determined, then the amount of the other reactants can also be calculated. This is illustrated in the image here, where the unbalanced equation is: : : However, the current equation is imbalanced. The reactants have 4 hydrogen and 2 oxygen atoms, while the product has 2 hydrogen and 3 oxygen. To balance the hydrogen, a coefficient of 2 is added to the product H2O, and to fix the imbalance of oxygen, it is also added ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rev Limiter
A rev limiter is a device fitted in modern vehicles that have internal combustion engines. They are intended to protect an engine by restricting its maximum rotational speed, measured in revolutions per minute (RPM). Rev limiters are Engine control unit, pre-set by the engine manufacturer. There are also aftermarket units where a separate controller is installed using a custom RPM setting. A limiter prevents a vehicle's engine from being pushed beyond the manufacturer's limit, known as the ''redline'' (literally the red line marked on the tachometer). At some point beyond the redline, engine damage may occur. Operation Limiters usually work by shutting off a component necessary for the combustion processes to occur, whether it be fuel, air or spark. Internal combustion engine#Compression ignition process, Compression-ignition engines use mechanical Governor (device), governors or limiters to shut off electronic fuel injectors. A Internal combustion engine#Spark ignition process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Valve Timing
Variable valve timing (VVT) is the process of altering the timing of a Poppet valve, valve lift event in an internal combustion engine, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with variable valve lift systems. There are many ways in which this can be achieved, ranging from mechanical devices to electro-hydraulic and camless systems. Increasingly strict emissions regulations are causing many automotive manufacturers to use VVT systems. Two-stroke cycle, Two-stroke engines use a Two-stroke power valve system, power valve system to get similar results to VVT. Background theory The valves within an internal combustion engine are used to control the flow of the intake and exhaust gases into and out of the combustion chamber. The timing, duration and lift of these valve events has a significant impact on engine performance. Without variable valve timing (variable valve lift), the valve timing is the same for all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honda Engines
commonly known as just Honda, is a Japanese multinational conglomerate automotive manufacturer headquartered in Minato, Tokyo, Japan. Founded in October 1946 by Soichiro Honda, Honda has been the world's largest motorcycle manufacturer since 1959, reaching a production of 500 million . It is also the world's largest manufacturer of internal combustion engines measured by number of units, producing more than 14 million internal combustion engines each year. Honda became the second-largest Japanese automobile manufacturer in 2001. In 2015, Honda was the eighth largest automobile manufacturer in the world. The company has also built and sold the most produced motor vehicle in history, the Honda Super Cub. Honda was the first Japanese automobile manufacturer to release a dedicated luxury brand, Acura, on 27 March 1986. Aside from their core automobile and motorcycle businesses, Honda also manufactures garden equipment, marine engines, personal watercraft, power generators, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
