What engine part is bolted to the top of the cylinder block?

What engine part is bolted to the top of the cylinder block? The answer is the cylinder head.

The cylinder head closes the upper end of the cylinders and forms the roof of each combustion chamber. Together with the piston and cylinder walls, it creates the sealed space where the air-fuel mixture burns. The head is secured to the block with strong head bolts or studs, while a head gasket seals the joint against combustion pressure, coolant and engine oil.

A common mix-up is the head gasket: it sits between the head and block but is not the structural part bolted on top. The intake manifold is attached to the cylinder head and supplies air, while the valve cover sits above the valvetrain and keeps oil inside.

Cylinder-head design varies with the engine. Modern overhead-camshaft heads commonly contain intake and exhaust ports, valves, camshafts and sometimes fuel injectors. Inline engines usually use one head; V engines generally use one head per cylinder bank, although Volkswagen’s narrow-angle VR6 uses one head for both banks.