What is the Function of a Camshaft?

[Jerry]

The camshaft is a component in a piston engine. Its function is to control the opening and closing actions of the valves. Below is a detailed introduction to the camshaft: 1. Main Body: The main body of the camshaft is a cylindrical rod approximately the same length as the cylinder group. It is fitted with several cams, which are used to drive the valves. The camshaft is supported within the camshaft bearing holes via camshaft journals, so the number of camshaft journals is an important factor affecting the support stiffness of the camshaft. If the camshaft stiffness is insufficient, it will bend and deform during operation, affecting the valve timing. 2. Design Principle: The side profile of the cam is egg-shaped. This design ensures sufficient intake and exhaust in the cylinder. Additionally, considering the durability and smooth operation of the engine, the valves should not experience excessive or large impacts during the acceleration and deceleration processes of opening and closing. Otherwise, it could lead to severe valve wear, increased noise, or other serious consequences. Therefore, the cam has a significant relationship with the engine's power, torque output, and smooth operation.

[LoganMarie]

I've been repairing car engines for over 20 years and know that the camshaft is one of the heart components of an engine. That shaft has multiple cams specifically controlling the opening and closing of intake and exhaust valves for each cylinder. When you start the engine, the rotating camshaft precisely pushes the valve stems with its cams, ensuring valves open and close at exactly the right timing whether at high RPM or idle. This directly affects air-fuel mixture intake/exhaust, making combustion more complete and boosting power output. But once the camshaft wears out or deforms - say from insufficient lubrication causing surface roughness - valves won't seal properly or may fail to open, leading to engine knocking, power loss or even stalling. Modern vehicles often use dual overhead camshafts or variable valve timing technology to improve fuel efficiency and throttle response. I must remind everyone: checking oil quality and filters every 5,000 km prevents camshaft overheating damage. During repairs, always align timing marks when installing new parts - misalignment causes catastrophic failure, and that's no minor issue.

[DeJameson]

As an average driver, I don't know much about the technical details of camshafts, but I can feel they determine the breathing rhythm of the engine. That shaft is hidden inside the engine, rotating to push those valves open and shut, acting like a precise switch. Good cars accelerate smoothly and are more fuel-efficient precisely because the camshaft ensures fast air intake and clean fuel combustion. If it malfunctions—like when wear causes inaccurate opening and closing—you'll experience reduced power or black smoke from the exhaust, along with soaring fuel consumption. Last time, the mechanic said my car's rough idle was due to a slightly bent camshaft, and replacing it fixed the issue. For routine maintenance, never neglect oil changes, as poor-quality oil accelerates camshaft wear. From a user's perspective, regular upkeep makes the engine more durable and prevents breakdowns. Though small, the camshaft impacts the overall driving experience, so I always remind mechanics to check it.

[OKimberly]

I love modifying racing engines, and camshafts are absolutely crucial for performance upgrades. They control the valve timing and lift in the high RPM range—essentially determining how much air the engine can breathe. Factory camshafts are conservative, but after installing high-lift cams, the valves stay open longer with greater lift, giving the engine explosive power at high revs and lightning-fast acceleration. However, excessive modifications can cause rough idling. New variable valve timing technology uses sensors to automatically adjust opening/closing timing and lift, eliminating the drawbacks of old fixed camshafts. With proper maintenance—I regularly inspect camshaft surface lubrication—track performance stays consistent. For performance upgrades, the camshaft is always step one.