What is bolted to the block in a vehicle?

The cylinder head is a crucial component that is bolted to the engine block in a vehicle. Its primary function is to house the combustion chamber, where the air-fuel mixture is ignited to power the engine. The cylinder head also contains various passages for coolant and oil, as well as the valves and, in many cases, the camshaft.

By being bolted to the engine block, the cylinder head effectively seals the top of the cylinders while allowing for the necessary interactions with the pistons as they move up and down during the combustion process. This tight bond between the cylinder head and block is essential for maintaining the engine's structural integrity and preventing leaks of gases or fluids.

Other components, such as the oil pan, intake manifold, and exhaust manifold, may also be bolted to the engine but serve different functions within the system. The oil pan collects and stores engine oil, the intake manifold distributes the air-fuel mixture to the cylinders, and the exhaust manifold collects exhaust gases from the cylinders and directs them out of the engine. While all of these parts are important for the engine's operation, the cylinder head's role as the assembly that directly interacts with and contains the combustion process distinguishes it as the correct answer.