What is the difference between a single overhead camshaft and a double overhead camshaft?
2 Answers
The difference between a single overhead camshaft and a double overhead camshaft lies in the cylinder configuration: a single overhead camshaft has one camshaft arranged within a cylinder head, while a double overhead camshaft has two camshafts arranged within a cylinder head. The camshaft position sensor is a sensing device, also known as a synchronization signal sensor. Because the camshaft position sensor can identify when a cylinder piston is about to reach top dead center, it can also be called a cylinder identification sensor. The working principle of the camshaft position sensor is: 1. Collect the position signal of the valve camshaft and input it into the ECU; 2. The ECU identifies the top dead center of cylinder 1 compression to perform sequential fuel injection control, ignition timing control, and knock control.
In my years of car repair experience, the difference between single overhead camshaft (SOHC) and double overhead camshaft (DOHC) is quite significant. SOHC uses a single camshaft to control all valve operations, featuring a simple structure that's less prone to failure and cheaper to maintain, making it ideal for regular family cars. DOHC, on the other hand, employs two separate camshafts to independently manage intake and exhaust valves, allowing for more precise valve timing, faster response at high speeds, and smoother acceleration. However, DOHC engines are more complex than SOHC, easier to pair with turbochargers but costlier to repair. For daily commuting, SOHC is sufficient—hassle-free and economical; for long-distance driving or performance enthusiasts, DOHC feels like a whole different engine in terms of power. It also depends on the car's age: newer models often opt for DOHC for enhanced efficiency, while older vehicles may find SOHC more reliable. My advice? If you drive mostly for practicality, stick with SOHC for simplicity. But if you crave driving excitement, you'll appreciate DOHC's refined engineering.
