Cam on Car Engine
What is a Cam?
A cam is a mechanical device that converts rotary motion into linear motion. In a car engine, the camshaft drives the valves that open and close the combustion chambers. This allows the engine to breathe in air and fuel and expel exhaust gases.
How Does a Cam Work?
A cam is typically a cylindrical or oval-shaped piece of metal with a series of lobes and valleys. The lobes are raised sections that push on the valve stem when the cam rotates. The valleys are lower sections that allow the valve stem to move freely.
The camshaft is driven by the crankshaft through a timing belt or chain. As the camshaft rotates, the lobes and valleys push on the valve stems, causing the valves to open and close at the appropriate times.
Types of Cams
There are two main types of cams: overhead cams and cam-in-block cams.
- Overhead cams are located in the cylinder head, above the valves. They are driven by a timing belt or chain that runs from the crankshaft to the camshaft.
- Cam-in-block cams are located in the engine block, below the valves. They are driven by a timing chain that runs from the crankshaft to the camshaft.
Cam Timing
The timing of the camshaft is critical to the proper operation of the engine. The camshaft must rotate at the correct speed and in the correct sequence to ensure that the valves open and close at the appropriate times.
The timing of the camshaft is controlled by the timing belt or chain. The timing belt or chain is connected to the crankshaft and the camshaft. As the crankshaft rotates, the timing belt or chain turns the camshaft at the correct speed and in the correct sequence.
Cam Wear
Cams and camshafts can wear over time. This wear can cause the cam to lose its ability to open and close the valves properly. This can lead to a loss of power, fuel economy, and drivability.
There are a number of things that can cause cam wear, including:
- Lack of lubrication
- Dirt and debris
- Excessive heat
- Improper valve adjustment
Cam Replacement
If the cam or camshaft becomes worn, it will need to be replaced. Replacing a cam or camshaft is a complex and time-consuming process. It is important to have this work done by a qualified mechanic.
Conclusion
The cam is a critical component of the car engine. It is responsible for opening and closing the valves that allow the engine to breathe. The timing of the camshaft is critical to the proper operation of the engine. Cams and camshafts can wear over time, which can lead to a loss of power, fuel economy, and drivability. If the cam or camshaft becomes worn, it will need to be replaced.
