Definition

Noun A cylinder head is a detachable plate or cover that seals the top end of a cylinder in a reciprocating engine or pump. It forms the combustion chamber's roof and typically houses components like valves, spark plugs, and fuel injectors.

Usage

The term cylinder head is used to refer to this specific engine component. It is a key part of the engine's structure and sealing system. * The mechanic removed the cylinder head to inspect the valves. * A cracked cylinder head can cause a loss of compression and engine coolant. * This design features an aluminum cylinder head for reduced weight.

Advanced Usage

• Cylinder head gasket: The seal placed between the cylinder head and the engine block to ensure a tight, leak-proof closure of the combustion chamber and coolant/oil passages.
  • A blown cylinder head gasket is a serious engine problem.
• In engineering contexts, the performance of an engine is often discussed in relation to the design of its cylinder head, including the shape of the combustion chamber and the airflow through the ports.

Variants and Related Words

• Cylinder head cover (or valve cover): A separate cover that sits on top of the cylinder head to enclose the valvetrain.
• Cylinder block: The main structure of the engine that contains the cylinders, distinct from the detachable cylinder head.

Synonyms

• Head (informal, in automotive contexts)
  • The engine needs a new head.
• Cylinder cover

Related Phrases

• To deck the cylinder head: A machining process to ensure the mating surface of the cylinder head is perfectly flat.
• Overhead valve (OHV) / Overhead cam (OHC): Terms describing the valvetrain layout located within the cylinder head.

Noun

1. a detachable plate that covers the closed end of a cylinder chamber in a reciprocating engine or pump