1. Engine Systems and Components
Ag Powers

2. Objectives
Identify the categories of internal combustion engine systems in class notes.
Identify the components of the primary or compression systems.
Describe the components of an engine’s operating system.

3. Categories of internal combustion engine systems
Primary system
Operating systems
Accessory systems

4. Primary System
Creates the engine compression and converts the energy of combustion to mechanical energy.
Also referred to as the compression system.

5. Operating Systems Perform other engine functions.
Engine will not operate without operating systems.
Also referred to as auxiliary systems.
Examples: electrical system, cooling systems, etc.

6. Accessory Systems Not necessary for engine operation.
When they fail, the engine is still operable.
Example: power steering system

7. Components of Primary System
Piston
piston rings
Cylinder
Head gaskets
Cylinder head
Valves
Intake and exhaust
Valve springs
Spring retainers
Valve guides
Camshaft

8. Components of Operating System
Air intake system-
functions to provide a source of clean air necessary for the combustion of the air-fuel mixture.
Air cleaner- filtering device located on the outside of the engine.
Carburetor- provides fuel and air to the engine in correct proportions and volume.

9. Components of Operating Systems
Fuel System-
Delivers clean and adequate amounts of fuel to the cylinder.
Fuel tank
Fuel filter- acts as a cleaner for the fuel that passes through it.
Fuel pump- ensures that an adequate amount of fuel under the correct pressure is distributed throughout the rest of the system.
Fuel injection systems- inject fuel into the combustion chamber
Mechanical fuel injection systems- use mechanical type pumps
Electronic fuel injection systems- use electrically operated injectors

10. Components of Operating Systems
Exhaust system-
Removes the exhaust gases and particles from the combustion chamber.
Manages engine noise and heat transfer.
Exhaust manifold
Exhaust pipe
Muffler

11. Components of Operating Systems
Engine cooling system-
Manages the heat produced by the combustion of the air-fuel mixture.
Allows the engine to reach its optimum operating temperature and to maintain that temperature under varying conditions.
2 basic types:
Liquid cooling system
Air-cooled system

12. Engine Cooling Systems
Liquid cooling system-
Uses a liquid to transfer heat from engine components to the surrounding air.
Radiator- heat transfer device that acts as a cooling and storage area for the liquid combination of water and antifreeze.
Water pump- mechanical device that forces the coolant to flow through the system.
Thermostat- flow control valve that regulates temperature inside an engine by opening and closing.
Additional components of a liquid cooling system: radiator cap, water jacket, fan, fan belt, temperature gauge

13. Engine Cooling Systems
Air-cooled system-
transfers the heat of the engine components directly to the surrounding air.
Common on small gas engines.
Fins- used to increase the surface area in contact with the air so that engine heat can be transferred more efficiently.
Shroud- engine cover that directs cooling air across the engine fins.
Fan- force air through the engine cooling system.

14. Components of Operating Systems
Ignition system-
Starts the combustion of air-fuel mixture.
Compression ignition system-
No unique parts; part of the compression system
Spark ignition system-
Uses a high voltage electrical spark to ignite the compressed air and fuel mixture in the combustion chamber.
2 types:
Magneto-type ignition systems
Battery-type ignition systems

15. Spark Ignition Systems
Magneto- type ignition systems-
use magnets and coils to generate electrical pressure to arc the spark plug.
Flywheel magnet creates a magnetic field which cuts across the armature and coil assembly as the flywheel rotates, inducing voltage into the primary circuit.

16. Spark Ignition Systems
Battery-type ignition system-
Uses the energy from a battery and/or alternator to create the ignition spark.

17. Components of Operating Systems
Lubrication system-
Keeps internal engine parts coated with oil to:
Reduce friction
Enhance cooling
Seal internal engine components
Clean internal parts
Basic components
Oil filter
Pressure regulator
Oil pans
Oil pump

18. Components of Operating Systems
Starting system-
Used to turn the engine crankshaft until the engine starts.
Manual starting systems-
Common on small gas engines
Manually turning the crankshaft.
Rope starter
Electrical starting systems-
Solenoid-type switch controls the correct amount of voltage going to the starter.
Flywheel-