A four-stroke engine converts gasoline into motion using four cycles: intake, compression, combustion, and exhaust. It is the most common type of car engine because it is relatively efficient and inexpensive. The basic components include intake and exhaust valves, pistons, connecting rods, a crankshaft, and camshaft. During the intake stroke, the intake valve opens to allow an air-fuel mixture into the cylinder. In the compression stroke, the mixture is compressed to make it more combustible. The combustion stroke ignites the compressed mixture, creating motion. Finally, in the exhaust stroke, the exhaust valve opens to release gases from the cylinder.

1. Four-Stroke Engine BasicsFour-Stroke Engine Basics
Raghavendra Singh KashyapRaghavendra Singh Kashyap
Assistant professorAssistant professor
Dr.C.V.Raman University,BilaspurDr.C.V.Raman University,Bilaspur

2. The BasicsThe Basics
 A four-stroke engine:A four-stroke engine:
 Is an internal combustion engineIs an internal combustion engine
 Converts gasoline into motionConverts gasoline into motion
 Is the most common car engineIs the most common car engine
typetype
 Is relatively efficientIs relatively efficient
 Is relatively inexpensiveIs relatively inexpensive

3. Other Engine TypesOther Engine Types
 Two-stroke enginesTwo-stroke engines
 Diesel enginesDiesel engines
 Rotary enginesRotary engines
 Turbine enginesTurbine engines
 Steam enginesSteam engines

4. Basic Components of Four-Basic Components of Four-
Stroke EnginesStroke Engines
Intake Valve
Valve Cover
Intake Port
Head
Coolant
Engine Block
Oil Pan
Oil Sump
Crankshaft
Camshaft
Exhaust Valve
Spark Plug
Exhaust Port
Piston
Connecting Rod
Rod Bearings

5.  A.A. Intake Valve-Intake Valve- opens at theopens at the
proper time to let in air and fuel.proper time to let in air and fuel.

6.  B.B. Valve CoverValve Cover- Protects the- Protects the
valves and the valve springs.valves and the valve springs.
Keeps dirt out and lubricating oilKeeps dirt out and lubricating oil
in.in.

7.  C.C. Intake PortIntake Port- the passageway- the passageway
in a cylinder head for the fuelin a cylinder head for the fuel
and air to pass through.and air to pass through.

8.  D.D. HeadHead- a platform containing- a platform containing
most of the parts of themost of the parts of the
combustion chamber.combustion chamber.

9.  E.E. CoolantCoolant- circulating water- circulating water
and antifreeze to keep theand antifreeze to keep the
temperature regulated.temperature regulated.

10.  F.F. Engine BlockEngine Block- cast in one- cast in one
piece. The basis for most of thepiece. The basis for most of the
parts of the engine.parts of the engine.

11.  G.G. Oil PanOil Pan- where the oil is- where the oil is
collected and recirculated.collected and recirculated.

12.  H.H. Oil SumpOil Sump- the collected oil- the collected oil
primarily for lubricating theprimarily for lubricating the
crankshaft and rod bearingcrankshaft and rod bearing

13.  I.I. CamshaftCamshaft- a round shaft with- a round shaft with
lobes, that rotates to open andlobes, that rotates to open and
close the fuel and exhaustclose the fuel and exhaust
valves.valves.

14.  J.J. Exhaust ValveExhaust Valve- open at the- open at the
proper time to release theproper time to release the
exhaustexhaust

15.  K.K. Spark PlugSpark Plug- a device,- a device,
inserted into the combustioninserted into the combustion
chamber for firing an electricalchamber for firing an electrical
spark to ignite air-fuel mixturespark to ignite air-fuel mixture

16.  L.L. Exhaust PortExhaust Port- the- the
passageway in a cylinder head,passageway in a cylinder head,
for the exhaust to pass throughfor the exhaust to pass through

17.  M.M. PistonPiston- the part of the- the part of the
engine that moves up and downengine that moves up and down
in the cylinder converting thein the cylinder converting the
gasoline into motiongasoline into motion

18.  N.N. Connecting RodConnecting Rod- links the- links the
piston to the crankshaft.piston to the crankshaft.

19.  O.O. Rod BearingRod Bearing- used to reduce- used to reduce
friction to the rod and crankshaftfriction to the rod and crankshaft

20.  P.P. CrankshaftCrankshaft- converts the up- converts the up
and down motion of the pistonand down motion of the piston
into a turning, or rotating motioninto a turning, or rotating motion

21. The 4-Stroke CycleThe 4-Stroke Cycle
 1.1. IntakeIntake
 2.2.
 3.3.
 4.4.
Compression
Combustion
Exhaust

22.  IntakeIntake-- process ofprocess of
filling the cylinderfilling the cylinder
with the proper air-with the proper air-
fuel mixturefuel mixture
through the intakethrough the intake
valve.valve.

23.  CompressionCompression--
the process ofthe process of
compressing thecompressing the
air-fuel mixture inair-fuel mixture in
the cylinder tothe cylinder to
make it moremake it more
combustiblecombustible

24.  CombustionCombustion-the-the
process of ignitingprocess of igniting
the compressedthe compressed
air-fuel mixture toair-fuel mixture to
create motion andcreate motion and
the over all powerthe over all power
of the engine.of the engine.

25.  ExhaustExhaust- the- the
process ofprocess of
releasing thereleasing the
exhaust out ofexhaust out of
the cylinderthe cylinder
through thethrough the
exhaust valve.exhaust valve.

26. Thank YouThank You