What are the components of the engine valve train?
2 Answers
Engine valve train can be divided into two main parts: the valve group and the valve drive group. Here are the detailed explanations: 1. The valve group includes the valves and their associated components, whose composition is basically independent of the type of valve train. 2. The valve drive group consists of all components from the timing gear to those that actuate the valves, and its composition varies depending on the type of valve train. Its function is to drive the valves to open and close at the correct timing. 3. According to operational requirements, it timely opens and closes the intake and exhaust valves to introduce combustible gas into the cylinder and expel exhaust gases. At the same time, it drives components such as the distributor and fuel pump to operate.
I've worked in the auto shop for over a decade, specializing in valvetrain issues across various engines. Simply put, the valvetrain consists of the camshaft, valves (intake and exhaust), valve springs, lifters or rocker arms, plus the timing chain or belt. The camshaft rotates to actuate the lifters, opening valves to allow air flow in/out of combustion chambers, while valve springs act like little assistants ensuring prompt valve closure. Proper timing alignment is critical - misaligned chains/belts cause piston-to-valve contact, destroying engines. Common failures include stretched timing chains or broken springs. I recommend owners inspect/replace timing systems every 80,000km, especially on older vehicles, as valvetrain health directly impacts fuel efficiency and smooth starts. When hearing abnormal noises or experiencing poor acceleration, prioritize checking these components without delay.
