Nissan Ecology Oriented Variable Valve Lift and Timing (commonly known as VVL & VVT) is an

automobile A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods. The year 1886 is regarded ...

variable valve timing 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 var ...

technology developed by

Nissan , trading as Nissan Motor Corporation and often shortened to Nissan, is a Japanese multinational automobile manufacturer headquartered in Nishi-ku, Yokohama, Japan. The company sells its vehicles under the Nissan, Infiniti, and Datsun bra ...

. VVL varies the duration, and lift of

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

s by using

hydraulic Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counte ...

pressure switch between two different sets of

camshaft 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 (to operate the intake and exhaust valves), mechanically controlled ignition systems ...

lobes. VVT varies the valve timing throughout the RPM range. Together they function similarly to

Honda is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a producti ...

VTEC VTEC (Variable Valve Timing & Lift Electronic Control) 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 ...

system. The SR20VE is the most common engine with NEO VVL. There have been two main versions of this engine. The first version made and torque. This engine was used by Nissan from 1997 to 2001. It is found in the

Nissan Primera The is a large family car which was produced by the Japanese automaker Nissan from 1990 to 2007, for the markets in Japan and Europe. In Japan, it replaced the Auster/Stanza, and was exclusive to '' Nissan Prince Store'' locations. In North Am ...

Nissan Bluebird The is a compact car with a model name introduced in 1957. It has been Nissan's most internationally recognized sedan, in multiple body styles, and is known for its dependability and durability. The Bluebird originated from Nissan's first vehic ...

, and the

Nissan Wingroad The Nissan AD is a subcompact van and station wagon, wagon built by Nissan since 1982. The AD is sold under a different name when manufactured as a passenger car, called the . __TOC__ VB11 series In October 1982, the AD Van supplemented (a ...

. The second variant of the SR20VE is found only in the 2001 and later P12

. This version of the SR20VE makes , and torque. This engine is commonly known as the SR20VE '20V'. Although, in automotive terms, '20V' would normally be interpreted as having twenty valves, this is incorrect. The name '20V' is the name of the trim level of the

that it is found in. It is also a shortened version of the name SR20VE. This engine has 16 valves like the rest of the SR20 engines. This newer '20V' engine, along with the SR20VET, were the only SR20 engines to get restyled valve covers. It also came with an upgraded

intake manifold In automotive engineering, an inlet manifold or intake manifold (in American English) is the part of an engine that supplies the fuel/ air mixture to the cylinders. The word ''manifold'' comes from the Old English word ''manigfeald'' (from the ...

, which has longer runners and a larger throttle body (earlier SR20VE has 60 mm). Another version of the VVL SR engines, is the 1.6 L SR16VE. The engine block for the SR16VE is the same as the SR20VE; it also has the same cylinder bore. The crankshaft has a shorter stroke, which lowers the displacement, but allows the engine to safely rev to higher RPM. Although this engine has 1.6 L of displacement, it has more aggressive camshaft specifications. It manages to make . The camshafts from this engine are considered to be an upgrade for SR20VE owners. From 1997 to 1998,

produced 500 limited-edition SR16VE N1 engines. These engines made . They had further upgraded camshafts, upgraded intake manifold using eight injectors and a larger throttle body. These engines were found in the limited-edition

Nissan Pulsar The is a line of automobiles produced by the Japanese automaker Nissan from 1978 until 2000, when it was replaced by the Nissan Bluebird Sylphy in the Japanese market. Between 2000 and 2005, the name "Pulsar" has been used in Australia and New ...

VZ-R N1. They were only sold in Japan. The most powerful VVL engine so far is the SR20VET. The SR20VET is a turbocharged '20V' SR20VE. It uses a Garrett GT2560LS, and makes .

's technical information about this engine states that it is 9:1

compression ratio The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values. A fundamental specification for such engines, it is measured two ways: the stati ...

, but it really adds up to 8.8:1. Compared to the

SR20DET The SR20DET is a straight-four four-stroke gasoline engine that is part of the SR family of engines from Nissan, produced from 1989 to 2002. It is a turbocharged version of the SR20DE engine and is a replacement of the CA18DET engine. The S ...

(used in the

Nissan Silvia The is the series of small sports cars produced by Nissan. Versions of the Silvia have been marketed as the 200SX or 240SX for export, with some export versions being sold under the Datsun brand. The name "Silvia" is derived from Sylvia, t ...

, and Bluebird), the SR20VET (aside from having VVL technology) has improved airflow in the

cylinder head In an internal combustion engine, the cylinder head (often abbreviated to simply "head") sits above the cylinders and forms the roof of the combustion chamber. In sidevalve engines, the head is a simple sheet of metal; whereas in more modern ...

, higher compression, and also improved coolant passages. In 1998

's RB engine was also improved using the NEO Head Technology (but no VVL), which provided the motor better fuel economy and lower exhaust emissions to keep up with emission standards. One difference from

system is that NEO VVL engages the change of intake and exhaust cams independently for a flatter, more consistent power band. On the SR20VE, the intake camshaft is switched at 5000 rpm, and the exhaust at 6500 rpm. However this trait was not included on the newer '20V' version, as both camshafts engage at the same RPM.

Sources

New Zealand Primera ClubNissan Primera Owners Club
- Valuable Primera Information
SR20forum VVL FAQ
FAQ about VVL
Nissan Japan
Official Nissan of Japan site
NeoVVL Owners Club
The Resource for the NeoVVL Engine {{nissan Nissan Variable valve timing

See also

Sources