What Is the “Top” of an Engine Called?

The top of an engine is typically called the cylinder head, and the very uppermost visible piece is the valve cover (also called a rocker or cam cover) that sits on top of the head; mechanics also refer to this area collectively as the “top end.” This naming reflects how modern engines are split into upper (valves, cams, intake) and lower (block, crank, pistons) sections.

Where the Term Fits on an Engine

In most automotive contexts, the engine’s “top” is the area where air enters, fuel and air are metered, and valves are actuated—centered around the cylinder head. The head bolts to the engine block and contains the passages and hardware that control airflow and combustion. On V-shaped engines (V6, V8), there are two cylinder heads—one per bank—each with its own valve cover. Inline engines usually have a single head and cover. The phrase “top end” commonly encompasses the head, valve train, and attached intake/exhaust hardware.

Main Parts You’ll Find at the Top

The top of the engine contains several components that manage airflow, ignition or injection, and valve timing. Here are the key elements you’ll typically see or service in that area.

• Cylinder head: Houses combustion chambers, intake and exhaust ports, valves, and—on many engines—the camshaft(s). It bolts to the block and mates via the head gasket.
• Valve cover (rocker/cam cover): The removable cover sealing the top of the head and valvetrain; its gasket is a common source of oil leaks.
• Valvetrain: Includes camshaft(s), lifters/tappets, rocker arms or finger followers, springs, and valves. Controls when air-fuel enters and exhaust exits.
• Intake manifold and throttle body: Directs air (and sometimes fuel) into the head’s intake ports; often sits atop or alongside the head.
• Exhaust manifold: Bolts to the head’s exhaust ports; on some transverse engines it may be more visible from the top.
• Ignition or injection hardware: Gasoline engines place spark plugs and ignition coils in or on the head; diesels use high-pressure injectors (and often glow plugs).
• Head gasket: The critical seal between the head and block, keeping compression, coolant, and oil in their proper passages.

Together, these components enable the engine to breathe, ignite or inject fuel, and maintain compression—core functions concentrated at the “top” of the engine.

How the “Top” Differs by Design

Engine architecture influences exactly what you see and what “top” includes. The essentials remain, but layout and terminology can vary.

• OHV (pushrod) engines: The camshaft sits in the block; pushrods actuate rockers under the valve cover. The head still contains valves and ports.
• OHC/DOHC engines: One or two camshafts live in the head, driven by a belt or chain—often visible at the top/front under timing covers.
• Inline vs. V vs. flat: Inline engines have one head; V engines have two heads and two valve covers; flat/boxer engines place heads on opposite sides.
• Gasoline vs. diesel: Gas engines mount spark plugs and coils in the head; diesels have injectors (and sometimes glow plugs) and heavier clamping for high compression.
• Motorcycles/small engines: “Top end” may explicitly include the piston and cylinder along with the head; two-strokes omit valves and use ports instead.

Despite these differences, the cylinder head remains the functional “top,” capped by a valve or cam cover and flanked by intake and exhaust hardware.

Common Issues at the Top and What They Mean

Because the top houses precision valvetrain and sealing surfaces, several well-known issues originate here. Recognizing them helps with maintenance and diagnosis.

1. Valve cover gasket leaks: Oil seeping onto the head or exhaust; often fixed with a new gasket and proper torque.
2. Head gasket failure: Overheating, white exhaust, oil-coolant mixing, or loss of compression; requires careful diagnosis and significant repair.
3. Timing belt/chain wear: Rattles at the top/front, cam/crank correlation codes, poor running; follow service intervals to prevent major damage.
4. Warped/cracked head: Usually from overheating; can cause misfires, coolant loss, or pressurized cooling systems.
5. Plug well oil intrusion and coil failures: Oil in spark plug tubes from leaking tube seals causes misfires and coil damage.

Keeping cooling systems healthy and replacing gaskets and timing components on schedule preserves the top end’s reliability and performance.

Terminology Quick Guide

These related terms can help you describe or search for the right parts when discussing the top of an engine.

• Top end: The assembly comprising the cylinder head, valvetrain, and attached intake/exhaust hardware; on some powersports engines includes the piston and cylinder.
• Cylinder head (“head”): The core upper engine casting; one per bank on V/flat engines.
• Valve cover (rocker/cam cover): The removable cover over the head and valvetrain, sealed by a gasket.
• Not to be confused: “Top Dead Center (TDC)” is a crankshaft position, not a part of the engine.

Using the correct term—head, valve cover, or top end—makes communication and parts sourcing more precise.

Summary

The “top” of an engine is the cylinder head, capped by the valve (rocker/cam) cover; together with the valvetrain and attached intake/exhaust, this area is often called the “top end.” Layout varies by engine design, but the function—airflow control, combustion sealing, and valvetrain operation—anchors the meaning across vehicles.

What is the engine lid called?

The engine lid is called a hood in American English and a bonnet in British English. The term used depends on the specific country and region, as both words refer to the hinged panel that covers the engine in a car. 
Key Differences by Region

• Hood: Opens in new tabThis is the term commonly used in the United States and Canada for the lid that opens to access the engine. 
• Bonnet: Opens in new tabThis is the term used in many Commonwealth countries, including the UK, Australia, and New Zealand. 

Other Considerations

• Frunk: Opens in new tabIn some electric vehicles, there is no front-mounted engine, so the front compartment may be called a “frunk,” or front trunk. 
• Rear-Engine Vehicles: Opens in new tabIn rear-engine vehicles, the rear cover that provides access to the engine is also referred to as the engine cover or, in some cases, the “hood” or “bonnet,” depending on the location. 

What is the top part of a motor called?

The top of an engine is primarily the cylinder head, which seals the top of the engine block and forms the combustion chamber. It also houses key components like the valves that control the flow of air and exhaust, spark plugs, and, in many engines, the camshaft and intake manifold.
 
Here’s a breakdown of the top of the engine:

• Cylinder Head: Opens in new tabThis is the main component at the top of the engine block, sealing the combustion chambers and housing the valves, spark plugs, and other internal components. 
• Valves: Opens in new tabLocated in the cylinder head, these open and close to allow the fuel-air mixture into the cylinder and let out exhaust gases. 
• Spark Plugs: Opens in new tabThese igniters are found in the cylinder head and are responsible for igniting the fuel-air mixture in each cylinder. 
• Camshaft: Opens in new tabThis rotating shaft actuates the valves, opening and closing them in a precise sequence. 
• Intake Manifold: Opens in new tabThis component distributes the air or air-fuel mixture to the cylinders for combustion. 
• Engine Head Gasket: Opens in new tabThis critical seal sits between the cylinder head and the engine block, preventing leaks of fluids and combustion gases. 
• Cylinder Head Cover: Opens in new tabA protective cover on top of the cylinder head that shields the internal components. 

What is the cap on the engine called?

Breather caps are commonly used with combustion engines. Also known as breather valves, they are designed to regulate the internal pressure of a given space. As the pressure inside of a combustion engine increases, the breather cap will release it so that it doesn’t blow any mechanical seals.

What are engine parts called?

The different parts that make up your car’s engine consist of: the engine block (cylinder block), the combustion chamber, the cylinder head, pistons, the crankshaft, the camshaft, the timing chain, the valve train, valves, rocker arms, pushrods/lifters, fuel injectors, and spark plugs.