Manufacturers like to use a lot of acronyms on their cars. Variable valve lift (VVL) and variable valve timing (VVT) are two of the most popular ones. These systems sound pretty similar, but what do ...

Ducati has announced it will introduce new engine technology that will boost power and torque, improve fuel economy, reduce emissions and won’t affect servicing intervals. Ducati Testastretta engine ...

What is VVL? What is VVT? How does VVL/VVT work? What is variable valve lift? What is variable valve timing? We're going to ...

The bike that won the title of “world’s fastest production motorcycle” at the turn of the century could soon sport a bit of tech that will support hi-rev performance at lower emissions… but at what ...

Most modern variable valve-timing (VVT) systems use a cam phaser that rotates the position of each cam­shaft relative to the timing chain. Think of making a record turntable go faster or slower by ...

Every aspect of an engine is a compromise: torque for horsepower, efficiency for emissions, performance for fuel economy, compression for octane tolerance. During the evolution of the internal ...

In order to set a stage for what follows, let's first revisit some of the fundamentals involved in how valve timing relates to power output. And to further clarify how "power" is defined in the ...

Valve overlap—that crucial interval when both the intake and exhaust valves are open, expressed in degrees of crankshaft rotation—is typically a fixed parameter and always a compromise. For example, ...

The Mitchell mechanical Variable Valve Timing (VVT) system is described. The way in which it exploits variable angular velocity to change valve timing is explained. The system was used in a programme ...