3. INTRODUCTION
An engine is a mechanical device that converts thermal
energy into mechanical work
Thermal energy can be obtained from chemical energy of
fuel by burning it in anyone of the following arrangements;
Outside of the engine and transporting pressurized hot gases or
steam to move pistons of the engine, called as External
Combustion Engine (ECE).
Inside engine cylinders generating pressure to move pistons,
called as Internal Combustion Engine (ICE).
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
4. Based on arrangement of cylinder:
a) Single cylinder
b) Inline Engine
c) V Type Engine
d) Opposed cylinders Engine
e) W-Engine
f) Opposed Piston Engine
g) Radial Engine
Based on arrangement of Valve:
a) L – Head
b) I – Head
c) F – Head
d) T – Head
CLASSIFICATION OF ENGINE
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
5. Based on construction:
Two Stroke Engine
Four Stroke Engine
Based on ignition:
Spark Ignition Engine
Compression Ignition Engine
Based on number of cylinder:
Single cylinder
Twin cylinder
Three cylinder
Four cylinder
Six cylinder
CLASSIFICATION OF ENGINE
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
6. In an internal combustion engine, the top of the cylinder is closed with a separate cast piece called
the engine head / cylinder head. The cylinder head is bolted to the upper part of the cylinder block.
This joint is covered by a head gasket. It consists of a combustion chamber, spark plugs, and
sometimes valves.
The cylinder head includes passages that deliver air and fuel to the cylinders, and which allow
cylinder head is usually made of gray iron or aluminum alloy.
ENGINE HEAD
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
7. PICTORIAL VIEWS OF ENGINE HEAD(MEHRAN 800CC)
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
8. The cylinder head is made up of many parts, some major components are as follows;
1. Head Gasket
2. Intake and exhaust ports
3. Head Valves
4. Head Combustion Chamber
5. Spark Plugs
6. Head Camshaft
7. Valve Spring
ENGINE HEAD COMPONENTS
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
9. 1) HEAD GASKET:
• The head gasket, usually made from a thin piece of steel, seals the joint between the
head.
• Without the gasket the seal between them, the two components would fail, causing a loss
reduce the power output of the engine.
• Water could also enter the cylinder chamber and mix with engine oil, causing overheating
components.
2) INTAKE AND EXHAUST PORT:
• The intake and exhaust ports are part of the cylinder head. The intake port is meant to
into the cylinder head and combustion chamber.
• After the combustion process, the gases are removed from the combustion chamber by
build-up of internal pressure, which can result in an explosion.
COMPONENTS FUNCTION
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
10. 3) HEAD VALVES:
• An engine has valves to close and open, the purpose of which is to stop or prevent the
combustion chamber.
• In an internal combustion engine, each cylinder has two valves – the intake valve is
is smaller.
4) HEAD COMBUSTION CHAMBER:
• The head combustion chamber is called the core of the engine. In which the air-fuel
to move the vehicle.
• Combustion chambers are available in various shapes and sizes. Well, it depends on the
application of the vehicle.
COMPONENTS FUNCTION
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
11. 5) SPARK PLUGS:
• The spark plugs provides power to the combustion chamber to ignite the air/fuel
• Plugs are mounted on the cylinder heads, their tips leading directly to the combustion
threaded to ensure an airtight seal.
6) HEAD CAMSHAFT:
• The cylinder head also includes the camshaft. In this, the camshaft operates to open and
• The camshaft is one of the engine block components, uses a belt drive the cylinder head
COMPONENTS FUNCTION
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
12. 7) VALVE SPRING:
• The valve spring function is to hold the valve position in order to close tightly.
• The valve position is pointing down, with the spring then the valve seeds will be depressed to
head. So, there is no gap.
• In addition, the spring use to recover the valve position after pressed. When the camshaft
If there is no spring, it will be always open and this could cause a leak.
COMPONENTS FUNCTION
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
13. Following are the types of cylinder head / Engine head:
1. Flat head cylinder head:
A flat head engine, is an internal combustion engine with its poppet valves (also called mushroom valve) contained within
the engine block, instead of the engine head, as in an overhead valve engine.
Flat heads were widely used internationally by automobile manufactures from the late 1890s until the mid-1950s but were
replaced by more efficient overhead valve and overhead camshaft engines.
TYPES OF ENGINE HEAD
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
14. 2. Overhead valve cylinder head:
An overhead valve (OHV) engine is a piston engine whose valves are located in the cylinder head above the combustion
chamber. This contrasts with earlier flat head engines, where the valves were located below the combustion chamber in the
engine block.
The camshaft in a traditional OHV engine is located in the engine block. The motion of the camshaft is transferred
using pushrods and rocker arms to operate the valves at the top of the engine
TYPES OF ENGINE HEAD
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
15. 3. Overhead camshaft cylinder head:
An overhead camshaft (OHC) engine is a piston head where the camshaft is located in the cylinder head above
the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below
the combustion chamber in the engine block.
TYPES OF ENGINE HEAD
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
16. The engine head plays an important role in a vehicles. Some of the functions are as follows;
It provides the mounting for various components such as inlet and outlet exhaust valves and ducts, spark plugs, fuel
injectors, and camshafts. In addition, it gives way to coolant, oil, and combustion gases.
The cylinder block absorbs the heat produced by the engine and, therefore, generates cooling to prevent engine failure.
It seals the combustion chamber and serves as the engine’s mechanical control powerhouse. It also takes away the
compression resulting from the combustion pressure.
FUNCTION OF ENGINE HEAD
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
17. Following are the applications of cylinder head:
1. The engine head is integrated with the cylinder block, in some cases commonly done in racing cars to achieve a gas-
tight joint.
2. The detachable head type has more benefits than integral construction.
3. However, some heavy-duty engines requiring higher cooling rates such as those in racing cars may use copper alloys.
APPLICATIONS OF ENGINE HEAD
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
18. The cylinder head contains most of the mechanical components of an engine. As a result, it determines the engine’s
behavior in terms of torque, emissions, cooling, and even acoustics.
They're key to controlling air flow in and out of the cylinders and fuel deployment.
It is a detachable metal that fits over the top of the cylinder block. Which is mainly used to close the combustion
chamber of the engine from above.
CONCLUSION
INTERNAL COMBUSTION ENGINE LAB DEPARTMENT OF MECHANICAL ENGINEERING
