What does DOHC mean?
2 Answers
DOHC (Double Overhead Camshaft) refers to a dual overhead camshaft configuration in Chinese. This dual camshaft technology originates from racing cars and primarily controls the timing difference between intake and exhaust valves. Below is relevant information: 1. Dual camshafts can adjust the valve overlap angle, allowing for greater horsepower output. However, they tend to have insufficient torque at low RPMs and, due to their complex mechanical structure, can present certain maintenance challenges. 2. The intake and exhaust valves are arranged on separate camshafts. In the former setup, all valves are driven by a single camshaft via pushrods, but due to the differing positions of the valves in the intake tract, precise operation cannot be maintained, resulting in slightly inferior performance. The latter setup avoids this drawback, delivering better performance, but requires an additional camshaft—this is the overhead dual camshaft (DOHC) configuration. Many modern engines introduced in recent years adopt this design. Generally, DOHC engines offer higher performance and are widely used in F1 racing cars. However, due to their complex manufacturing process, they are more costly. In contrast, SOHC (Single Overhead Camshaft) engines have a simpler configuration, better durability, and can meet both the power demands of general customers and their economic requirements.
From my decades of experience in car repair, DOHC stands for Double Overhead Camshaft, meaning an engine is equipped with two camshafts—one dedicated to controlling the intake valves and the other managing the exhaust valves, ensuring precise and specialized operation. This design allows for more flexible valve operation, delivering quicker response at high RPMs, resulting in smoother acceleration and reduced vibration. The downside? It's a bit more complex in structure, potentially making repairs and part replacements more expensive. However, it significantly improves fuel efficiency and power output, which is why many cars now come with it as standard. If you're curious about how an engine works internally, think of valve control as a coordinated dance—DOHC acts like two precise conductors, far outperforming the single-camshaft SOHC. In daily driving, you'll notice better fuel economy and stronger power. I recommend paying attention to this parameter when choosing a car, especially for sports models or hybrid versions, where it performs at its best.
