What is the function of the valve train?
4 Answers
The function of the valve train is: 1. To open and close the intake and exhaust valves of each cylinder in accordance with the working cycle and ignition sequence requirements of the engine; 2. To allow the combustible mixture or air to enter the cylinder in a timely manner, and to allow exhaust gases to be discharged from the cylinder promptly; 3. During the compression and power strokes, to close the valves to ensure the sealing of the combustion chamber. The valve train includes: 1. The valve group: valves, valve guides, valve seats, valve locks, and valve springs; 2. The valve drive group: camshaft, timing gear, timing chain, timing belt, tappet, pushrod, rocker arm, rocker shaft, and rocker bracket.
I've been studying engines for many years. Simply put, the valve train is the key component that ensures the engine breathes properly. It controls the precise opening and closing of intake and exhaust valves. During engine operation, the up-and-down movement of pistons requires air intake and exhaust gas expulsion. The valve train coordinates valve actions through the camshaft, ensuring smooth combustion in the cylinders. If it malfunctions, it may cause engine noise, vibration, or even stalling – especially in urban traffic congestion where acceleration becomes sluggish. I've tried adjusting valve timing before, and after the repair, the engine immediately regained vitality with significantly reduced fuel consumption. Modern vehicles even feature variable valve timing technology that automatically adjusts opening/closing timing based on speed to improve power response. Overall, its precise operation directly affects the vehicle's smoothness, fuel efficiency, and power output. Regular inspection of chain or belt wear can prevent failures and extend service life.
As a long-time driver, I've experienced the importance of the valve train. It acts like the breathing coordinator of the engine, ensuring smooth air intake into the cylinders while expelling exhaust gases. When driving, whether the engine idles smoothly or accelerates powerfully depends entirely on its operation. Once, my car's valve timing was off, causing severe shaking during startup, and my mechanic friend said it was a valve train issue. When functioning properly, it helps fuel burn efficiently, reducing extra fuel consumption. During daily commutes, you can feel the ease, especially with continuous power on highways. For maintenance, I make it a habit to have the mechanic check valve clearance during servicing to prevent looseness. Small issues like noise or starting difficulties can be restored with timely repairs. This is crucial for driving safety, as engine health significantly impacts overall driving comfort.
Over the years of DIY car repairs, I've come to understand the pivotal role of the valve train. It controls the opening and closing timing of valves, allowing air in and exhaust out to ensure proper combustion. Once the chain loosens or the belt snaps, the engine immediately starts rattling with halved power. I've encountered several air leakage issues, and the simple fix is replacing aged lifters or camshaft components. For prevention, inspect the timing condition every 20,000 kilometers to avoid misalignment. Symptoms may include stalling or skyrocketing fuel consumption when faulty, but acceleration response improves significantly after repairs. This greatly benefits the vehicle's lifespan.
