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The AMB series engine was an inline 4-cylinder engine, manufactured from 2001 to 2003 by the Volkswagen Group in Ingolstadt, Germany as a replacement for the earlier 1.8T engines, such as the AEB-type engine. As opposed to the AEB, the AMB had thinner wrist pins (19 mm instead of 20 mm).
The cam can be seen as a device that converts rotational motion to reciprocating (or sometimes oscillating) motion. [clarification needed] [3] A common example is the camshaft of an automobile, which takes the rotary motion of the engine and converts it into the reciprocating motion necessary to operate the intake and exhaust valves of the cylinders.
Valve timing and the valve profile are continuously altered according to conditions and engine load. For improved responsiveness on cold starts, VarioCam Plus raises the amount of lift and retards valve timing. At medium revs with minimal loads, the valve lift is lowered and timing advanced to help minimize fuel consumption and emissions.
In most piston engines, the camshaft(s) are mechanically connected to the crankshaft. The crankshaft drives the camshaft (via a timing belt, timing chain or gears), which in turn actuates the intake and exhaust valves. [1] These valves allow the engine to inhale air (or an air/fuel mixture) and exhale the exhaust gasses. [2]
The disadvantage of this system is its cost. Even though it is a fairly simple device it requires very accurate helical machining and very careful assembly. The helical camshaft prototypes typically cost about $1500 in machining and materials. [citation needed] This figure would reduce greatly in production. The cost of the helical camshaft is ...
The Alfa Romeo Twin Spark engine, introduced in the 1987 Alfa Romeo 75, also uses variable valve timing. [3] [4] The Alfa system varies the phase (not the duration) of the cam timing and operates on the inlet camshaft. [5] Alfa Romeo's variator is a cylindrical chamber that contains a pressure chamber and piston along with helical splines.
Camshafts normally have one lobe per valve, with a fixed valve duration and lift. Although many modern engines use camshaft phasing, adjusting the lift and valve duration in a working engine is more difficult. Some manufacturers use systems with more than one cam lobe, but this is still a compromise as only a few profiles can be in operation at ...
A tappet or valve lifter is a valve train component which converts rotational motion into linear motion in activating a valve. It is most commonly found in internal combustion engines , where it converts the rotational motion of the camshaft into linear motion of intake and exhaust valves, either directly or indirectly.