The camshaft is responsible for opening and closing the engine's valves at the appropriate times during the combustion cycle. In a pushrod engine, the camshaft is located in the engine block and uses pushrods to open and close the valves. In an overhead cam engine, the camshaft is located directly above the valves and uses rocker arms to open and close them.
OHC engines have several advantages over pushrod engines. First, they are more efficient because the camshaft is located closer to the valves, which reduces friction and allows for more precise valve timing. Second, OHC engines are more compact because the camshaft is not located in the engine block. Third, OHC engines are quieter because the camshaft is not driven by a timing chain or belt.
OHC engines are more expensive to manufacture than pushrod engines, but they offer better performance and efficiency. They are typically found in high-performance and luxury vehicles.
Here is a more detailed explanation of how an overhead cam works:
1. The camshaft is driven by the engine's crankshaft through a timing belt or chain.
2. As the camshaft rotates, it causes the rocker arms to move up and down.
3. The rocker arms push on the valve stems, which open and close the engine's valves.
4. The valves control the flow of air and fuel into and out of the engine's cylinders.
The timing of the camshaft is critical to the engine's performance. If the valves are not opened and closed at the correct times, the engine will not run efficiently.
