Published On August 26, 2019
With the efforts to learn more about engine performance and to make the best use of every ounce of horsepower out of their engines by manually adjusting valve lash and ignition timing, American automotive giants made big breakthrough, they developed variable valve timing (VVT), a new system which utilized advanced electronic technology to use various electronic signals from the ignition system via a variable valve timing solenoid. It was not until the early 1990s, when the VVT system was spread--- nearly all automotive makers succeeded in variable valve timing (VVT) system production. Nowadays, you can find a VVT system in almost all the automobiles sold in any country where the automobile market has matured.
Then comes the question, what pushes those car manufacturers to install a VVT system in their products? The VVT system cannot save the cost, and whether it’s Ford or General Motors, the primary goal of automobile companies is to make profits.
So we can conclude that the VVT system does have so great charm for potential car buyers that car manufacturers have to attach importance to it.
VVT has better performance of high power and low fuel consumption than other automobile engines. VVT means "intelligent variable valve timing system". It can improve combustion efficiency and reduce friction loss so that it can be easily operated and accelerated at low and medium speed.
Besides, VVT makes the engine lighter and more compact by using aluminum alloy cylinder block and miniaturization of the oil pump.
The biggest characteristic of VVT system is that the intake camshaft can be controlled according to the state of the engine, and the timing of valve distribution can be optimized by adjusting the camshaft rotation angle, so as to obtain the best timing of valve distribution, so as to improve the torque in all speed ranges, and greatly improve the fuel economy, effectively improve the power and performance of the vehicle, and reduce the oil. Consumption and exhaust emissions.
The VVT system consists of sensors, electronic control units, hydraulic control valves, and controllers. It can be divided into two kinds according to the installation parts of the controllers: one is the vane VVT mounted on the exhaust camshaft, such as Camry Toyota; the other is the spiral groove VVT mounted on the intake camshaft, called Reick. Sass LS430 and other high-end cars are using this type.
Variable valve timing (VVT) helps to provide smoother idling, better power delivery for everyday needs, improved fuel economy, and superior emissions control.
With VVT, it is possible to have the timing altered to match the engine speed, torque requirements, and valve overlap. This increases both performance and fuel economy. Another great advantage of VVT is its ability to take some of the load off the crankshaft by opening the valve before the end of the combustion stroke.
When talking about the VVT system, people may ask, why should we install them instead of EGR (Exhaust Gas Recirculation)? Then comes a keyword--nitrous oxides. The VVT system controls the combustion temperature and the formation of nitrous oxide by controlling the time of inert gas remaining in the combustion chamber in the next combustion cycle while EGR cannot precisely control. In a word, the VVT system’s great control ability made EGR out of date.