What is the function of valves?

[Dennis]

The function of valves is specifically responsible for introducing air into the engine and expelling exhaust gases after combustion. In terms of engine structure, they are divided into intake valves and exhaust valves. The intake valve's role is to draw air into the engine to mix with fuel for combustion; the exhaust valve's role is to expel the burned exhaust gases and dissipate heat. Here is additional information: 1. Composition: A valve consists of a valve head and a stem. The shape of the valve head can be flat, spherical, or trumpet-shaped, among others. Flat valve heads are simple in structure, easy to manufacture, have a small heat absorption area, and are lightweight, making them suitable for both intake and exhaust valves. The valve stem is cylindrical and continuously moves back and forth in the valve guide, requiring its surface to be heat-treated and polished. The shape of the valve stem end depends on the method of fixing the valve spring, with the common structure using two half-lock pieces to secure the spring seat. The valve stem end has a groove for installing the lock pieces, while some use a lock pin for fixation, with a hole at the end for installing the lock pin. 2. Current Status: To improve intake and exhaust efficiency, multi-valve technology is now widely used, commonly featuring four valves per cylinder (though some designs have three or five valves per cylinder, following the same principle, such as the Audi A6's engine). For a four-cylinder engine, this totals 16 valves, often indicated as "16V" in automotive specifications. This multi-valve structure easily forms a compact combustion chamber, with the fuel injector positioned centrally, allowing the air-fuel mixture to burn more quickly and uniformly. The weight and opening of each valve are appropriately reduced, enabling faster opening and closing speeds.

[Elsa]

The valve in the engine acts like a gate, controlling the airflow in and out of the cylinder. After driving my car for several years, I've realized that the valve's most critical function is to allow fresh air to mix with fuel for combustion, generating power to push the piston, and then expelling the exhaust gases. If the valve gets stuck or doesn't close properly, the engine will shake, lose power, fuel consumption will skyrocket, or it may even stall—especially frustrating in traffic jams. Regular maintenance shouldn't be overlooked; periodic carbon deposit cleaning can extend its lifespan. Simply put, it controls the engine's breathing. Without it, the car won't move, just like a person struggling without oxygen. I once had a valve issue that cost me hundreds to fix, so now I pay more attention to abnormal engine sounds and get them checked promptly.

[MacEvelyn]

The valves in the engine are essentially intake and exhaust gates, controlling the air-fuel mixture intake and exhaust processes. After years of repairing cars, common issues I've seen are excessive carbon buildup on valves or weak springs, leading to poor sealing—resulting in the engine struggling, with reduced power and increased fuel consumption. Their core functions are twofold: opening the intake passage to let the air-fuel mixture in and opening the exhaust passage to clear out the waste gases. This cycle is essential for generating power, and neither can be neglected. I recommend car owners check their valve condition every 10,000 kilometers—don't wait for a major failure to fix it, as costs will double and compromise driving safety. The inspection is simple: listen for unusual noises or test drive at low speeds. Proper maintenance keeps your car running stronger.

[IkerLee]

The valve is a delicate component in the engine, primarily responsible for controlling the flow of gases inside the cylinder. It opens during the intake stroke to allow the fresh air-fuel mixture to enter and opens during the exhaust stroke to release the burnt gases after compression and combustion. This design ensures efficient combustion and reduced emissions. Poor sealing can lead to compressed gas leakage, resulting in energy waste. Modern engine valves are made from upgraded materials for enhanced durability. For daily maintenance, it's advisable to use fuel additives to remove deposits and prolong service life.

[VonJoanna]

From a driving perspective, valves directly influence the car's breathing rhythm, ensuring the engine operates efficiently and avoiding the awkwardness of sluggish idling. My car is an older model, and whenever valve issues arise, acceleration becomes sluggish with trailing smoke, and fuel consumption increases. The core function operates in two steps: during intake, the valve opens to allow the fuel mixture into the cylinder for combustion; during exhaust, the valve opens to expel waste gases. This cycle sustains power and reduces pollution for environmental protection. I've learned that developing a habit of checking the engine temperature before turning off the car daily helps detect early faults. Simple maintenance routines like regular oil changes can prevent valve sticking, saving energy and ensuring safety.

[OmarAnn]

The valve in a car engine acts like a gate, specifically managing the flow of air and gases in and out of the cylinder. Its function is straightforward: when open, it allows fresh air mixed with fuel to enter in preparation for combustion; when closed, it compresses the mixture to generate power; after combustion, it opens again to expel exhaust gases. Without it, the engine wouldn't start or would run unevenly. When I first learned to drive, I didn't understand this, but later, by watching maintenance videos, I grasped the principle. Combining this with maintenance advice—using high-quality engine oil and avoiding frequent short trips to reduce wear—can protect the valve's normal operation and ensure a smooth journey.