At present more cars on the multi-valve engine and four-valve. Four-cylinder engine with 16-valve, 6-cylinder engine with 24-valve, eight-cylinder engine has 32 valve. For example, in Japan LEXUS LS400 is the engine cylinder 32-valve 8. Valve increase the number will increase accordingly with gas agencies devices, more complex structures, generally two overhead camshaft cylinder in order to control both sides of the centerline of the valve chamber. Valve layout centres on both sides of the combustion chamber in the cylinder tilted position, which is, in order to maximize the diameter of the valve head, increase airflow through the area, improve the ventilation performance, create a spark plug in the central compact combustion chamber, to the mixture the rapid combustion.

Some people ask, since Valve good, why we did not see more than one valve 6-cylinder engine? Thermodynamic called a "screen area" concept, referring to the Park valve week multiplied by the valve lift, valve open space. "Curtain zone" that the greater the valve open space is, the greater the feed rate.

Audi 100 cars to the engine as an example, the four-valve "screens Area" value than the two-valve "screens Area" value, in the inlet to the state half of the state to exhaust the 7.0% 10. Of course, every one of the things it must have the scope valve is not to say that the more "screen area" of the bigger According to the experts when each of the cylinder valve to six, the "curtain district," it's worth it will be dropped, and the valve body more complex, the greater the cost.