S-VT
Encyclopedia
S-VT, or Sequential Valve Timing, is an automobile
variable valve timing
technology developed by Mazda
. S-VT varies the timing of the intake
valve
s by using hydraulic pressure to rotate the camshaft
. S-VT was introduced in 1998 on the ZL-DE engine and is used in the B-
, Z-
, MZR-
and J-
families of engines.
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
variable valve timing
Variable valve timing
In internal combustion engines, variable valve timing , also known as Variable valve actuation , is a generalized term used to describe any mechanism or method that can alter the shape or timing of a valve lift event within an internal combustion engine...
technology developed by Mazda
Mazda
is a Japanese automotive manufacturer based in Fuchū, Aki District, Hiroshima Prefecture, Japan.In 2007, Mazda produced almost 1.3 million vehicles for global sales...
. S-VT varies the timing of the intake
Intake
An intake , or especially for aircraft inlet, is an air intake for an engine. Because the modern internal combustion engine is in essence a powerful air pump, like the exhaust system on an engine, the intake must be carefully engineered and tuned to provide the greatest efficiency and power...
valve
Poppet valve
A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide...
s by using hydraulic pressure to rotate the camshaft
Camshaft
A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part.-History:An early cam was built into Hellenistic water-driven automata from the 3rd century BC. The camshaft was later described in Iraq by Al-Jazari in 1206. He employed it as part of his automata,...
. S-VT was introduced in 1998 on the ZL-DE engine and is used in the B-
Mazda B engine
The Mazda B-series engine is a small-sized, iron-block, inline four-cylinder with belt-driven SOHC and DOHC valvetrain ranging in displacement from 1.1L to 1.8L. It was used from front-wheel drive economy applications to the turbocharged full-time 4WD 323 GTX and rear-wheel drive Miata as well as...
, Z-
Mazda Z engine
The Mazda Z-series is a smaller inline 4-cylinder gasoline engine ranging in displacements from 1.3L to 1.6L. They are the evolution of the cast-iron block B-engine....
, MZR-
Mazda MZR engine
MZR is the brand name of a generation of Straight-4 engines engineered and built by the Mazda Motor Corporation between 2001 and 2011. The MZR generation includes gasoline and diesel powered engines ranging in displacements from 1.3L to 2.5L. All gasoline-powered MZRs feature an all-aluminum block...
and J-
Mazda J engine
The Mazda J-family are a range 60-degree V6 engines featuring a cast iron cylinder block and alloy heads with belt-driven DOHC or SOHC. This is Mazda's only cast-iron V6...
families of engines.