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, ...

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 ...

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 ...

The first production car engine with variable valve timing (VVT) came from Alfa Romeo in 1980. It was installed in the fuel-injected Alfa Romeo Spider. Before this, a few experimental systems existed, ...

There is so much going on with internal combustion engines (ICEs) these days, it can give you a headache just reading about them. That's why we do the research for you and then cram it into bite-size ...

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 ...

The hunt for efficient engine valve technology can be a never-ending journey into cam timing, various combustion cycles, and lift and duration adjustments. For that reason, some companies believe ...

Variable valve timing isn’t necessarily a new idea, but it is new to BMW motorcycles. With a freshly designed 1,254 cc two-cylinder flat engine, VVT is arriving in BMW bikes for the first time with an ...

Do you know what a timing belt or a timing chain is and what they do? Could you find them on your vehicle's engine if you had to? If you answered no, don't sweat it. Both are buried behind a lot of ...