Nissan Ecology Oriented Variable Valve Lift and Timing (commonly known as VVL) is an
automobile variable valve timing technology developed by
Nissan. VVL varies the timing, duration, and lift of
valves by using
hydraulic pressure switch between two different sets of
camshaft lobes. It functions similarly to
Honda's
VTEC system.
The
SR20VE is the most common engine with NEO VVL. There have been two main versions of this engine. The first version made 187 hp (139 kW) and 145 lb·ft (197 N·m) torque. This engine was used by Nissan from 1997 to 2001. It is found in the
Nissan Primera,
Nissan Bluebird, and the
Nissan Wingroad.
The second variant of the
SR20VE is found only in the 2001 and later P12
Nissan Primera. This version of the
SR20VE makes 204 hp (152 kW), and 152 lb·ft (206 N·m) 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
Nissan Primera 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, is the only
SR20 engine to get a restyled valve cover. It also has an upgraded
intake manifold, which has longer runners and a larger 70 mm (2.8 in) 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 173 hp (129 kW). The camshafts from this engine are considered to be an upgrade for
SR20VE owners.
From 1997 to 1998,
Nissan produced 500 limited-edition
SR16VE N1 engines. These engines made 197 hp (147 kW). They had further upgraded camshafts, upgraded intake manifold using eight injectors and a larger 70 mm (2.8 in) throttle body. These engines were found in the limited-edition
Nissan Pulsar 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 GT2560R turbocharger, and makes 280 PS (206 kW; 276 hp).
Nissan's technical information about this engine states that it is 9:1
compression ratio, but it really adds up to 8.8:1.[SUP]
[citation needed][/SUP] Compared to the
SR20DET (used in the
Nissan Silvia, and Bluebird), the
SR20VET (aside from having VVL technology) has improved airflow in the
cylinder head, higher compression, and also improved coolant passages.
In 1998
Nissan's
RB engine was also improved using the VVL NEO Head Technology, which provided the motor better fuel economy and lower exhaust emissions to keep up with emission standards.
One difference from
Honda's
VTEC 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.
