The camshaft's job is to manage the poppet valves, basically opening and closing the intake and exhaust valves in the cylinder head. The rocker shaft enables the intake and exhaust valves to operate, driven by the camshaft. The rocker cover protects the rocker shaft from oil and dirt.
The rocker cover is bolted on to the cylinder head to cover and shield the rocker shaft, and sealed with a rocket cover gasket. The rocker cover gasket, usually made of rubber and cork, is sandwiched between the top of the engine and the rocker cover, providing a secure seal to prevent leaks.
The camshaft powers the rocker shaft or arm which put pressure on the valves, causing the valves to open. The valves are sprung loaded which enables them to close again. The spring functions to maintain contact between the valves and the rocker shaft. Aided by the rocker shaft, the camshaft works to make sure that the intake and exhaust valves are opening and closing at exactly the right time, enabling the correct amount of air and fuel to flow into the engine and burn in the cylinders for the engine to ignite or spark at the right time.
If the rocker shaft gets clogged up with dirt it will cause it to stop working properly so the rocker cover is vital in ensuring the rocker shaft can function properly and last longer. When you need to replace this part, choosing to fit the rocker shaft will guarantee perfect compatibility with the make and model of your vehicle.