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A stratified charge engine describes a certain type of internal combustion engine, usually spark ignition (SI) engine that can be used in trucks, automobiles, portable and stationary equipment. The term "stratified charge" refers to the working fluids and fuel vapors entering the cylinder. Usually the fuel is injected into the cylinder or enters as a fuel rich vapor where a spark or other means are used to initiate ignition where the fuel rich zone interacts with the air to promote complete combustion. A stratified charge can allow for slightly higher compression ratios without "knock," and leaner air/fuel ratio than in conventional internal combustion engines.
A four-strokeengine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed:
- Intake: Also known as induction or suction. This stroke of the piston begins at top dead center (T.D.C.) and ends at bottom dead center (B.D.C.). In this stroke the intake valve must be in the open position while the piston pulls an air-fuel mixture into the cylinder by producing vacuum pressure into the cylinder through its downward motion. The piston is moving down as air is being sucked in by the downward motion against the piston.
- Compression: This stroke begins at B.D.C, or just at the end of the suction stroke, and ends at T.D.C. In this stroke the piston compresses the air-fuel mixture in preparation for ignition during the power stroke (below). Both the intake and exhaust valves are closed during this stage.
- Combustion: Also known as power or ignition. This is the start of the second revolution of the four stroke cycle. At this point the crankshaft has completed a full 360 degree revolution. While the piston is at T.D.C. the compressed air-fuel mixture is ignited by a spark plug or by heat generated by high compression, forcefully returning the piston to B.D.C. This stroke produces mechanical work from the engine to turn the crankshaft.
- Exhaust: Also known as outlet. During the exhaust stroke, the piston, once again, returns from B.D.C. to T.D.C. while the exhaust valve is open. This action expels the spent air-fuel mixture through the exhaust valve.
Engine tuning is the adjustment or modification of the internal combustion engine or Engine Control Unit (ECU) to yield optimal performance and increase the engine's power output, economy, or durability. These goals may be mutually exclusive; an engine may be de-tuned with respect to output power in exchange for better economy or longer engine life due to lessened stress on engine components.
VTEC 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 camshaft profiles and hydraulically selects between profiles. It was invented by Honda engineer Ikuo Kajitani. It is distinctly different from standard VVT systems which change only the valve timings and do not change the camshaft profile or valve lift in any way.
In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, 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.
VVT-i, or Variable Valve Timing with intelligence, is an automobile variable valve timing technology developed by Toyota. The Toyota VVT-i system replaces the Toyota VVT offered starting in 1991 on the 5-valve per cylinder 4A-GE engine. The VVT system is a 2-stage hydraulically controlled cam phasing system.
MIVEC is the brand name of a variable valve timing (VVT) engine technology developed by Mitsubishi Motors. MIVEC, as with other similar systems, varies the timing of the intake and exhaust camshafts which increases the power and torque output over a broad engine speed range while also being able to help spool a turbocharger more quickly and accurately.
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. The air / fuel ratio needed to stoichiometrically combust gasoline, by contrast, is 14.64:1. The excess of air in a lean-burn engine emits far less hydrocarbons. High air–fuel ratios can also be used to reduce losses caused by other engine power management systems such as throttling losses.
The Honda D series inline-four cylinder engine is used in a variety of compact models, most commonly the Honda Civic, CRX, Logo, Stream, and first-generation 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 66 PS (49 kW) in the Logo to 130 PS (96 kW) in the Civic Si. D-series production commenced 1984 and ended 2005. D-series engine technology culminated with production of the D15B 3-stage VTEC (D15Z7) which was available in markets outside of the United States. Earlier versions of this engine also used a single port fuel injection system Honda called PGM-CARB, signifying the carburetor was computer controlled.
The Honda K-series engine is a line of four-cylinder four-stroke car engine introduced in 2001. The K-series engines are equipped with DOHC valvetrains and use roller rockers on the cylinder head to reduce friction. The engines use a coil-on-plug, distributorless ignition system with a coil for each spark plug. This system forgoes the use of a conventional distributor-based ignition timing system in favor of a computer-controlled system that allows the ECU to control ignition timings based on various sensor inputs. The cylinders have cast iron sleeves similar to the B- and F-series engines, as opposed to the FRM cylinders found in the H- and newer F-series engines found only in the Honda S2000.
The Honda F-Series engine was considered Honda's "big block" SOHC inline four, though lower production DOHC versions of the F-series were built. It features a solid iron or aluminum open deck cast iron sleeved block and aluminum/magnesium cylinder head.
The Bourke engine was an attempt by Russell Bourke, in the 1920s, to improve the two-stroke internal combustion engine. Despite finishing his design and building several working engines, the onset of World War II, lack of test results, and the poor health of his wife compounded to prevent his engine from ever coming successfully to market. The main claimed virtues of the design are that it has only two moving parts, is lightweight, has two power pulses per revolution, and does not need oil mixed into the fuel.
The Toyota KR engine family is a straight-3 piston engine, designed by Daihatsu, a subsidiary of Toyota. The 1KR series uses aluminium engine blocks and chain driven DOHC cylinder heads. It uses multi-point fuel injection, and has 4 valves per cylinder. Some versions have VVT-i variable valve timing. The engine is exceptionally light: 69 kg (152 lb) with all ancillaries. This is due to the nature of the applications and weight of city cars.
The L-series is a compact inline-four engine created by Honda, introduced in 2001 with the Honda Fit. It has 1.2 L (1,198 cc), 1.3 L (1,318 cc) and 1.5 litres (1,497 cc) displacement variants, which utilize the names L12A, L13A and L15A. Depending on the region, these engines are sold throughout the world in the 5-door Honda Brio Fit/Jazz hatchback Honda Civic and the 4-door Fit Aria/City sedan. They can also be found in the Japanese-only Airwave wagon and Mobilio MPV.
The Mitsubishi 6B3 engine is a range of all-alloy piston V6 engines developed by Mitsubishi Motors. Currently, only one engine has been developed, a 3.0 L (2,998 cc) V6 first introduced in the North American version of the second generation Mitsubishi Outlander which debuted in October 2006.
In a spark ignition internal combustion engine, Ignition timing refers to the timing, relative to the current piston position and crankshaft angle, of the release of a spark in the combustion chamber near the end of the compression stroke.
Engine efficiency of thermal engines is the relationship between the total energy contained in the fuel, and the amount of energy used to perform useful work. There are two classifications of thermal engines-
- Internal combustion and
- External combustion engines.
The fifth-generation Honda Civic is an automobile produced by Honda from 1991 until 1995. It debuted in Japan on September 9, 1991. At its introduction, it won the Car of the Year Japan award for the second time. Fifth generation cars were larger than their predecessors, had more aerodynamic bodies, and the wheelbase was increased to 257 cm (101.3 inches)—for the three-door hatchback—and to 262 cm (103.2 inches)—for the four-door sedan. The Civic Shuttle station wagon was not part of the fifth generation and was dropped for overseas markets, while the previous generation wagon continued in Japan and Europe.
The seventh-generation Honda Civic is an automobile produced by Honda from 2000 until 2005. It debuted in September 2000 as a 2001 model. Its exterior dimensions stayed similar to the outgoing predecessor, with interior space significantly increased, bumping up it up to the compact car size designation. A notable feature was the flat rear floor that gave better comfort to the rear seat passengers. This generation abandoned the front double wishbone suspension, used previously from fourth to sixth generations, replacing it with MacPherson struts. This generation was the last to offer 4WD variants.
A helical camshaft is a type of mechanical variable valve actuation (VVA) system. More specifically it is a camshaft that allows the valve opening duration to be varied over a wide, continuous, step-less range, with all of the added duration being at full valve lift.
References
- ↑ Kong-Ngai Wong. "VTEC". asia.vtec.net.
- ↑ Wong, K. N. (May 2000). "D15B 1.5l SOHC VTEC". asia.vtec.net. Retrieved 24 January 2019.