4+stroke+engine+cycle

1. http://www.youtube.com/watch?v=4HPV73v7Ub8
Part 1

3. A cylinders displacement is the volume of the
cylinder when the piston is at BDC.
It is the sum of the displacement of each cylinder.
It is defined as the volume of air/fuel mixture an
engine can draw in.

4. Ex: 700 cc (cubic centimetres)
1000 cc = 1 Litre

5. Example : Vehicle has 4 cylinders
: Each cylinder has a volume of 700cc
: 700cc X 4 = 2800cc
: 2800cc = 2.8 Litre

6. Torque is the term used to describe a rotating
force.
More torque generally means a car can accelerate
faster
Torque is the actual reading of how “hard” and
with how much “Force” the engine turns.

7. Horsepower: 1 hp = 33,000 lb-ft / min
One horsepower is the ability to lift 33000 pounds one
foot in one minute
The horsepower specification for an engine tells you
how much power the engine can produce. 
Horsepower is the rate at which the engine does work

8. Formula:
HORSEPOWER = (TORQUE * RPM) / 5252
A engine that makes 300 pound-feet of torque at 4,000
RPM produces
 [(300 x 4,000) / 5,252] 228 horsepower at 4,000 RPM

9. Think about:
Torque being how hard you can pound away on
bicycle pedals
Horsepower being how fast you can spin the
bicycle pedals.

10. What is engine displacement?
What is horsepower?
What is Torque?
What are the different parts of an engine?

11. http://www.youtube.com/watch?
v=60QX5RY_ohQ&feature=related
Part 2

12. Spark plug
Inlet valve
Exhaust valve
Cylinder
Piston
The four-stroke engine

13. Is a can-shaped part closely fitted inside the
cylinder.
Piston rings consist of compression rings and oil
rings.
Crankshaft takes the up-down motion of the piston
and convertors it to a rotation motion
 Connecting rod connects the piston to the
crankshaft.

14. The 4 Stroke engine cycle consist of these:
1) Intake 180degree
2) Compression 180 degree
3) Power/ Combustion 180 degree
4) Exhaust 180 degree
Total engine revolution 720 degree
One complete engine cycle consists of 4 engine
strokes.

15. The Intake Stroke consist of the piston travelling
down.
Intake valves are open to allow Air/Fuel mixture to
come into the combustion chamber.

16. Intake plastic ducts
Intake manifolds

18. -Fuel injectors are electronically controlled valves
that spray fuel to mix with air.
-Creating that air fuel mixture
-

19. It is an electrical device that fits into the cylinder
head and ignites air fuel mixtures.

20. Inlet valve
open
INTAKE STROKE
The four-stroke engine
Exhaust
valve
closed

21. Inlet valve
open
Piston down
INTAKE STROKE
The four-stroke engine
Exhaust
valve closed

22. Inlet valve
open
Piston down
INTAKE STROKE
The four-stroke engine
Fuel in
Exhaust
valve
closed

23. Inlet valve
open
Piston down
INTAKE STROKE
The four-stroke engine
Fuel in
Exhaust
valve
closed

24. What is the purpose of the intake system?
What is the purpose of the spark plug?
What is the purpose of the fuel injector?
What is happening during the intake stroke?

25. Part 3
http://www.youtube.com/watch?v=q4Bk2TJJ6TM

26. Compression stroke consist of the piston travelling
back up.
Both intake and exhaust valves are closed
Air fuel mixture is now being compressed

27. Inlet valve
closed
COMPRESSION STROKE
The four-stroke engine
Piston up
Exhaust
valve
closed

28. Inlet valve
closed
COMPRESSION STROKE
The four-stroke engine
Piston up
Exhaust
valve closed

29. Inlet valve
closed
COMPRESSION STROKE
The four-stroke engine
Piston up
Exhaust
valve
closed

30. The piston is now at the TDC
Spark plug ignites, creating a spark that ignites
the compressed air fuel mixture.
Explosion is created and the piston is forced back
down.
Hence the Power stroke
Both valves are still closed

31. Inlet valve
closed
POWER STROKE
The four-stroke engine
BANG
Exhaust
valve
closed

32. Inlet valve
closed
POWER STROKE
The four-stroke engine
Piston down
powerfully
Exhaust
valve
closed

33. Inlet valve
closed
POWER STROKE
The four-stroke engine
Piston down
powerfully
Exhaust
valve
closed

34. Inlet valve
closed
POWER STROKE
The four-stroke engine
Exhaust
valve
closed

35. Exhaust stroke the piston is travelling up
Exhaust valve is open
Intake valve is Closed
Exhaust gases being pushed out by piston

36. Inlet valve
closed
EXHAUST STROKE
The four-stroke engine
Exhaust valve
closed

37. Inlet valve
closed
EXHAUST STROKE
The four-stroke engine
Exhaust valve
open
Piston up
Exhaust gases
out

38. Inlet valve
closed
EXHAUST STROKE
The four-stroke engine
Exhaust valve
open
Piston up
Exhaust gases
out

39. Inlet valve
open
INTAKE STROKE
The four-stroke engine
Exhaust valve
closed

40. And so the
cycle
continues!!

41. The exhaust system is needed to provide a
pathway for exhaust fumes to be filtered and to
reduce noise.
Exhaust manifold
Catalytic convertor
Muffler

43. - What is the purpose of the compression stroke
and what is happening
-What is the purpose of the power stroke and what
is happening?
-What is happening during the exhaust stroke?
 What is the purpose of the exhaust system?

44. http://www.youtube.com/watch?
v=IYWUWMmimjQ&feature=related
http://videos.howstuffworks.com/auto/car-
parts-videos-playlist.htm#video-30374
Video of 4 Stroke cycle

46. http://www.youtube.com/watch?
v=YB_JCUw9SoU&feature=related