A camshaft is a shaft that contains a row of pointed cams in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines, mechanically controlled ignition systems and early electric motor speed controllers.
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.
Variable valve timing (VVT) is the process of altering the timing of a 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.
Nissan Ecology Oriented Variable Valve Lift and Timing is an automobile variable valve timing technology developed by Nissan. VVL varies the duration, and lift of valves by using hydraulic pressure switch between two different sets of camshaft lobes. VVT varies the valve timing throughout the RPM range. Together they function similarly to Honda's VTEC system.
VarioCam is an automobile variable valve timing technology developed by Porsche. VarioCam varies the timing of the intake valves by adjusting the tension on the timing chain connecting the intake and exhaust camshafts. VarioCam was first used on the 1992 3.0 L engine in the Porsche 968.
MIVEC (Mitsubishi Innovative Valve timing Electronic Control system) 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.
Variable camshaft timing (VCT) is an automobile variable valve timing technology developed by Ford. It allows for more optimum engine performance, reduced emissions, and increased fuel efficiency compared to engines with fixed camshafts. It uses electronically controlled hydraulic valves that direct high pressure engine oil into the camshaft phaser cavity. These oil control solenoids are bolted into the cylinder heads towards the front of the engine near the camshaft phasers. The powertrain control module (PCM) transmits a signal to the solenoids to move a valve spool that regulates the flow of oil to the phaser cavity. The phaser cavity changes the valve timing by rotating the camshaft slightly from its initial orientation, which results in the camshaft timing being advanced. The PCM adjusts the camshaft timing depending on factors such as engine load and RPM.
The Toyota JZ engine family is a series of inline-6 automobile engines produced by Toyota Motor Corporation. As a replacement for the M-series inline-6 engines, the JZ engines were 24-valve DOHC engines in 2.5- and 3.0-litre versions.
The Toyota ZZ engine family is a straight-4 piston engine series. The ZZ series uses a die-cast aluminium engine block with thin press-fit cast iron cylinder liners, and aluminium DOHC 4-valve cylinder heads. The camshafts are chain-driven. The two 1.8 L members of the family, the 1ZZ and 2ZZ, use different bore and stroke. The former was optimised for economy, with torque emphasised in lower revolutions per minute operating range, while the latter is a "square" design optimised for high-RPM torque, yielding higher peak power. The ZZ family replaced the extremely popular cast-iron block 4A engines.
The Toyota AZ engine family is a straight-4 piston engine series. The AZ series uses an aluminium engine block with cast iron cylinder liners and aluminium DOHC cylinder head. The engine series features many advanced technologies including slant-squish combustion chambers, offset cylinder and crank centers, and the VVT-i continuously variable intake valve timing system. The aluminium engine measures 626 mm (24.6 in) long, 608 mm (23.9 in) wide, and 681 mm (26.8 in) tall.
The Toyota GR engine family is a gasoline, open-deck, piston V6 engine series. The GR series has a 60° die-cast aluminium block and aluminium DOHC cylinder heads. This engine series also features 4 valves per cylinder, forged steel connecting rods and crankshaft, one-piece cast camshafts, a timing chain, and a cast aluminium lower intake manifold. Some variants use multi-port fuel injection, some have D4 direct injection, and others have a combination of direct injection and multi-port fuel injection or D4-S.
The Toyota S Series engines are a family of straight-four petrol engines with displacements between 1.8 and 2.2 litres, produced by Toyota Motor Corporation from January 1980 to August 2007. The S series has cast iron engine blocks and aluminium cylinder heads.
A valvetrain or valve train is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture into the combustion chamber, while the exhaust valves control the flow of spent exhaust gasses out of the combustion chamber once combustion is completed.
The Toyota UR engine family is a 32-valve dual overhead camshaft V8 piston engine series which was first introduced in 2006, as the UZ series it replaced began phasing out. Production started with the 1UR-FSE engine with D-4S direct injection for the 2007 Lexus LS. The series launched with a die-cast aluminum engine block, aluminum cylinder heads and magnesium cylinder head covers. All UR engines feature variable valve timing for both intake and exhaust cams or Dual VVT-i. Timing chains are used to drive the camshafts. The UR engine has been produced in 4.6, 5.0, and 5.7-liter displacement versions.
The Mitsubishi 4B1 engine is a range of all-alloy straight-4 piston engines built at Mitsubishi's Japanese "World Engine" powertrain plant in Shiga on the basis of the Global Engine Manufacturing Alliance (GEMA). Although the basic designs of the various engines are the same, their exact specifications are individually tailored for each partner. The cylinder block and other basic structural parts of the engine were jointly developed by the GEMA companies, but the intake and exhaust manifolds, the cylinder head's intake and exhaust ports, and other elements related to engine tuning were independently developed by Mitsubishi.
Nissan Variable Valve Event and Lift is an automobile variable valve timing technology developed by Nissan.
Acoustic Control Induction System, or ACIS, is an implementation of a variable-length intake manifold system designed by Toyota.
The Toyota NR engine family is a series of small inline-four piston engines designed and manufactured by Toyota, with capacities between 1.2 and 1.5 litres.
Variable valve timing (VVT) is a system for varying the valve opening of an internal combustion engine. This allows the engine to deliver high power, but also to work tractably and efficiently at low power. There are many systems for VVT, which involve changing either the relative timing, duration or opening of the engine's inlet and exhaust valves.
Variable valve lift (VVL) is an automotive piston engine technology which varies the height a valve opens in order to improve performance, fuel economy or emissions. There are two main types of VVL: discrete, which employs fixed valve lift amounts, and continuous, which is able to vary the amount of lift. Continuous valve lift systems typically allow for the elimination of the throttle valve.
