Explain various engine components ?
An engine comprises of a few hundred components : small and big, stationary and moving, metallic
and non-metallic , casted and forged and made by other processes.
and non-metallic , casted and forged and made by other processes.
The components of an engine can be grouped under 2 categories.
1. Stationary or Structure forming components. (which forms the mechanism)
2. Moving or mechanism forming components.
Important mechanism forming components are as follows:-
piston , piston rings, gudgeon pin , connecting rod
crank , crankshaft
camshaft ,
valves, valve operating mechanism , timing gears
chain and sprocket
belts and pulleys
flywhhel
Important structural components are as follows :
cylinder block ,
cylinder head ,
gaskets
cylinder liner
crankcase
inlet manifold, exhaust manifold.
Oil pan
resonator
muffler (silencer)
vibration damper
bearings
fasteners
turbocharger
Spark plug for SI /Petrol engine ,
Fuel injector / pump for CI /Diesel engine
fig 1
fig 2
Car Engine Parts
The core responsibility of the engine is to transform energy from fuel with a spark (in petrol
engine), to create the power to move.
This internal combustion creates tiny, contained explosions to produce movement.
While many of us think of the engine as one major component, it’s actually made up of several
individual components working simultaneously.
Car engines are designed around sealed, resilient metal cylinders.
Most modern vehicles have between four and eight cylinders, though some vehicles can have as
many as sixteen.
The cylinders are made to open and close at precisely the correct time to bring in fuel to combine
with the spark for burning internally, and to release the exhaust gases produced.
While there are several components on an engine, a list of the most essential car engine parts and
their functions are given below see diagram 1,2 and 3
Engine Block–
This is the very core of the engine.
Often made of aluminum or iron, it has several holes to contain the cylinders as well as provide
water and oil flow paths to cool and lubricate the engine.
Oil paths are narrower than the water flow paths.
The engine block also houses the pistons, crankshaft, camshaft, and between four and twelve
cylinders—depending on the vehicle, in a line, also known as inline, flat or in the shape of a V.
Pistons –
Are a cylindrical apparatus with a flat surface on top.
The role of the piston is to transfer energy created from combustion to the crankshaft to propel the
vehicle.
Pistons travel up and down within the cylinder twice during each rotation of the crankshaft.
Pistons on engines that rotate at 1250 RPM, will travel up and down 2500 times per minute.
Inside the piston, lie piston rings that are made to help create compression and reduce the friction
from the constant rubbing of the cylinder.
Crankshaft
The crankshaft is located in the lower section of the engine block, within the crankshaft journals
(an area of the shaft that rests on the bearings).This keenly machined and balanced mechanism is connected to the pistons through the connecting
rod.
Similar to how a jack-in-the-box operates, the crankshaft turns the pistons up and down motion into
a reciprocal motion, at engine speed.
Camshaft –
Varying from vehicle to vehicle, the camshaft may either be located within the engine block or in
the cylinder heads.
Many modern vehicles have them in the cylinder heads, also known as Dual Overhead Camshaft
(DOHC) or Single Overhead Camshaft (SOHC) and supported by a sequence of bearings that are
lubricated in oil for longevity.
The role of the camshaft is to regulate the timing of the opening and closing of valves and take the
rotary motion from the crankshaft and transfer it to an up and down motion to control the movement
of the lifters, moving the pushrods, rockers, and valves.
Cylinder Head–
Attached to the engine through cylinder bolts, sealed with the head gasket.
The cylinder head contains many items including the valve springs, valves, lifters, pushrods,
rockers, and camshafts to control passageways that allow flow of intake air into the cylinders during
the intake stroke as well as exhaust passages that remove exhaust gases during the exhaust stroke.
Timing Belt/Chain –
The camshaft and crankshafts are synchronized to ensure the precise timing in order for the engine
to run properly.
The belt is made of a heavy-duty rubber with cogs to grasp the pulleys from the camshaft and
crankshaft.
The chain, similar to your bicycle chain wraps around pulleys with teeth.
