The cylinder head bolt for Citroën 11CV PERFO/HY (manufactured from 7/52 to 11/58) is a crucial component for securing the cylinder head to the engine block. They ensure a tight and secure fit, essential for the combustion chamber and to prevent leaks. These bolts are specifically designed for vintage Citroën models and need to be strong enough to withstand the engine's pressure and heat. When replacing these bolts, it's important to use the correct specifications and torque settings to ensure the engine's optimal performance and durability.