ENGINE
*Engine is a Prime Mover. It is used to convert the heat energy obtained from the fuel into useful mechanical energy. It is the heart of the automobile.
*If the engine fails to work,the vehicle is dead.
*All automotive Engines are of the Internal Combustion Engine.(I.C. Engine)
I.C. Engine
*Inter Combustion Engine (I.C. Engine) is a hear engine that converts chemical energy in a fuel into mechanical energy.
*Chemical Energy of a fuel is first converted into thermal energy by means of combustion (or) oxidation with air inside the engine.
*This thermal energy is again converted into useful work through mechanical mechanism of the engine.
*Most of the I.C. Engines are reciprocating engines having pistons that reciprocate back and forth in cylinder internally within the engine.
Classification of engine
1.Type of Ignition
i)Spark Ignition Engines(S.I. Engines)
ii)Compression Ignition Engines(C.I. Engines)
​
2.Cycle of operation
i)Otto Cycle Engine
ii)Diesel Cycle Engine
iii)Dual Cycle Engine
​
3.Engine Cycle Per Stroke
i)Four stroke Cycle
ii)Two Stroke Cycle
​
4.Types of fuel Used
i)Petrol Engine
ii)Diesel Engine
iii)Gas Engine
​
5.Method of Cooling
i)Air-cooled engines
ii)water-cooled engines
​
6.Number of Cylinders
i)Single Cylinder Engine
ii)two Cylinder Engine
iii)three Cylinder Engine
iv)four Cylinder Engine
v)six Cylinder Engine
vi)Eight Cylinder Engine
vii)Twelve Cylinder Engine
viii)Sixteen Cylinder Engine
​
7.Valve Location
i)Square Engines
ii)L-Head Engines
iii)I-Head Engines
iv)F-Head Engines
v)T-Head Engines
8.Arrangement of Cylinders
i)Vertical Engine
ii)Horizontal Engine
iii)Radial Engine
iv)V-Engine
v)Opposed cylinder Engine
​
9.Speed of Engine
i)Low speed Engine
ii)Medium speed Engine
iii)High speed Engine
​
10.Types of Lubrication System
i)Wet sump lubrication system
ii)Dry sump lubrication system
​
11.Method of Governing
i)Quantity Governing
ii)Quality Governing
iii)Hit and miss Governing
​
12.Field of Operation
i)Automobile,Truck,Bus
ii)Locomotive Engine
iii)Stationary Engine
iv)Marine Engine
v)Aircraft Engine
ENGINE CONSTRUCTION
COMPONENTS OF I.C. ENGINE
1.Cylinder Block
*It is the main body of an engine which contains cylinders.The piston reciprocates inside the cylinder to develop power.
*It should be made of material which can resist high temperature and pressure.
*It is made of Grey Cast Iron (or) aluminium with steel sleeves.
*In water-cooled Engines, the cylinder block is provided which water jackets for circulation of cooling water.
2.Cylinder Head
*The cylinder head is bolted at the top of the cylinder block.
*It is also contains spark plug hole (or) injector hole and cooling water jacket.
*The materials used for cylinder heads are Cast Iron, Aluminium Alloy,etc.
3.Crank Case
*It supports crankshaft and camshaft with the help of bearings.
*Sometimes, the bottom crankcase may be used as oil sump.
*It is made of Cast Iron, Aluminium alloys (or) Alloy steels.
4.Oil Sump
*Oil sump is fitted at the bottom of crankcase by using gasket.It contains Lubricating Oil
*It is made of pressed Steel Sheet.
5.Cylinder Liners
*To prevents the cylinder into the wear, we are used in cylinder liners.
6.Piston
*It is the cylindrical shaped mass that reciprocates inside the cylinder.
*The top of the piston is called as Crown and sides are called Skirt.
*Piston is made of Cast Iron,Aluminium Alloy,Chrome-Nickel Alloy,Nickel Iron Alloy and Cast Steel.
*They are manufactures by Casting (or) Forging Method.
7.Connecting Rod
*It is used to connect the piston and crankshaft with the help of Bearing.
*It is small end is connected to the piston and its big end is connected to the crankshaft by the crank pin.
*The connecting rod must withstand heavy thrust and have a great strength and righdity.
*It is made of plain Carbon Steel,Aluminium Alloy and Nickel Alloy Steels.
8.Piston Rings
*To prevent gas Leakages.
*They are used to maintain air tight sealing between piston and cylinder to prevent the gas leak.
9.Crank Shaft
*It is used to convert reciprocating motion of the piston into rotary motion. Big end of the connecting to crankshaft.
*It can be single crank type for single cy;linder engines and multiple crank type for multi cylinder engine.
*They are made from hot billet Steel, Carbon Steel,Nickel Chromium and other heat treated Alloy Steels.
10.Flywheel
*The flywheel is heavy and perfectly balanced wheel usually connected to the rear end of the crankshaft. Flywheel serves as a energy reservoir.
*It stores energy during power stroke and releases during other strokes. That gives a constand output torque.
*It is made of Cast Iron (or) Cast Steel
11.Cam Shaft
*It is used to convert rotary motion of the camshaft into linear motion of the follower.
*This it is operates the inlet and exhaust valves through rocket arms. An additional cam is also provided to drive the fuel pump.
*It is driven by crankshaft through chain (or) Gear Train. It is rotated at half of the speed of the crankshaft.
12.Spark Plug
*The function of the spark plug is to ignite the air-fuel mixture after completing the compression stroke in the pertrol engine.
*It is usually mounted in the cylinder head. It is only used in petrol engine.
13.valves
*Valves are used for closing and opening passage of the cylinder.
*There are two valves in an engine cylinder namely at inlet and exhaust valves.
*Air -Fuel mixture enters in inlet valves and exhaust gases forced out through the exhaust valves.
i)Sleeve Valve
ii)Rotary Valve
iii)tappet valve
