Ads
related to: vvt valve lift kit
Search results
Results From The WOW.Com Content Network
The timing, duration and lift of these valve events has a significant impact on engine performance. Without variable valve timing or variable valve lift, the valve timing is the same for all engine speeds and conditions, therefore compromises are necessary to achieve the desired result in intake and exhaust efficiency . This has been described ...
One of the first practical VVT systems used a variator to change the phase [note 1] of the camshaft and valves. This simple system cannot change the duration of the valve opening, or their lift. [note 2] Later VVT systems, such as the helical camshaft or the movable fulcrum systems, could change these factors too. Despite this limitation, the ...
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.
Fiat 875 cc two cylinder TwinAir engine featuring Multiair technology. MultiAir or Multiair is a hydraulically-actuated variable valve timing (VVT) and variable valve lift (VVL) engine technology enabling "cylinder by cylinder, stroke by stroke" [1] control of intake air directly via a gasoline engine's inlet valves.
VVTL-i (Variable Valve Timing and Lift intelligent system) (also sometimes denoted as VVT-iL or Variable Valve Timing and Intelligence with Lift) is an enhanced version of VVT-i that can alter valve lift (and duration) as well as valve timing. It was introduced with the 16-valve 2ZZ-GE engine found in the 1999 Toyota Celica.
Porsche's more recent VarioCam Plus combines variable valve timing with two-stage lift on the intake side. The two-stage valve-lift function is performed by electro-hydraulically operated switchable tappets. Each of these 12 tappets consists of concentric lifters which can be locked together by means of a pin.
Nissan Ecology Oriented Variable Valve Lift and Timing (commonly known as VVL & VVT) 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.
First-generation Valvetronic systems can decrease the valve lift to a minimum of 0.3 mm, while second- and third-generation Valvetronic can decrease the lift to as little as 0.18 mm. On first-generation Valvetronic, the contact point on the intermediate arm for the camshaft was a contact pad; later systems use a roller which is less prone to wear.