Post: What do DVVT and CVVT mean for automobile engines（二）

So if you want to understand the engine CVVT and DVVT technology, it is easy to understand the working principle and working principle of VVT. CVVT is a technology that changes the cam from time to time according to the engine working conditions, changes the intake valve opening time early and late through the electro-hydraulic control system, and realizes the required valve overlap angle adjustment.
It should be noted that CVVT technology can only control the intake valve of the engine. Its advantages are fuel saving and high power-to-liter ratio. Its disadvantages are insufficient medium-speed torque. Its purpose is to reduce fuel consumption, obtain better torque, improve engine efficiency, and reduce pollutant emissions.
For example, Honda’s VVT technology is called VTEC. Honda’s technology cannot be used for the research and development of Nissan’s corresponding technology, so Nissan’s VVT technology is called VVL, and the engine with lifting function is called VVEL. Engines equipped with Nissan’s VVEL technology are of course rare in the market; Toyota’s name is simpler.
Directly named VVT; modern variable valve technology is CVVT, that is, continuously variable valve timing; this is of course just a name, which does not mean that VVT and other names cannot be changed frequently. The difference between DVVT engines and CVVT engines is that CVVT technology uses an electronic hydraulic system to continuously control the timing of the cam opening the intake valve.
DVVT technology is a variable timing technology that can control the intake and exhaust valves at the same time, so that the mixture of gasoline and air in the engine combustion chamber reaches the most suitable air-fuel ratio, which can increase power by 10%, reduce fuel consumption by 5%, and improve engine idle stability.
The advantage of DVVT is that it is advanced in technology, which can reduce intake and exhaust overlap, ensure stable combustion, reduce intake losses, improve combustion efficiency, improve fuel economy, and save fuel costs. Through this technology, the mixture ratio of air and fuel can be better adjusted, the formation of nitrogen oxides can be reduced, and emissions can be made more environmentally friendly. Compared with DVVT, CVVT is developed on the basis of VVT, but DVVT is more advanced than CVVT in technology. DVVT can change the intake and exhaust, change the air-fuel ratio, and reduce engine emissions, but CVVT can only change the continuous opening and closing of the intake valve, and other aspects cannot reach the technical height of DVVT. Therefore, CVVT is slightly behind DVVT, but now CVVT is still used on many models, which shows that its technical characteristics still have a market. If you want to know whether your car has a VVT system, you can search the Internet for necessary information first. Secondly, you can also check it yourself. Most manufacturers’ VVT technology is realized through the phase controller on the top of the camshaft, so the solenoid valve that controls VVT is visible on the side of the cylinder head close to the pulley. If there is a solenoid valve, it is a VVT. If there are two, it is DVVT.