What is the function of the engine valve train?
2 Answers
The function of the engine valve train is to open and close the intake and exhaust valves of each cylinder in a timely manner according to the working cycle and firing order requirements of each cylinder in the engine. This allows fresh charge to enter the cylinder promptly and exhaust gases to be expelled from the cylinder in time, while ensuring the sealing of the combustion chamber during the compression and expansion strokes. For gasoline engines, the fresh charge refers to the mixture of gasoline and air, while for diesel engines, it is pure air. The requirements for the valve train are that its structural parameters and configuration should help reduce intake and exhaust resistance. Additionally, the timing and duration of valve opening should be appropriate to ensure that both intake and exhaust processes are as complete as possible, thereby achieving greater power, torque, and emission performance.
I've been driving for almost twenty years, and the valve train is a pretty core component. It manages the opening and closing of the engine's intake and exhaust valves—when the engine runs, the valves must open on time to let fresh air and fuel into the cylinders, then close for combustion and exhaust. Without it, the engine wouldn't start at all, and idle would be rough with sluggish acceleration. The most common valve train issues I've encountered are stuck valves or worn-out springs, leading to unstable idle, doubled fuel consumption, and even stalling or breakdowns in severe cases. Maintenance is straightforward, though—just regularly check valve clearance and camshaft wear. Using high-quality oil can protect the parts and extend their lifespan. Modern cars often feature smart adjustment tech to optimize this system. Still, it's best to pay attention to unusual noises or power changes while driving to catch issues early and save big on repairs.
