1. FLIGHT POWER Know basic engine principles. 1. Define a list of terms related to basic engine principles. 2. Describe the mechanical, cooling, and ignition systems of the reciprocating engines.

2. Reciprocating Engines Internal or External Combustion?

3. Mechanical System Cylinder Piston Crankshaft Connecting Rod Valves

4. Mechanical System Cylinder Known as the engine’s combustion chamber Where the power is developed

5. Mechanical System Piston Fits snugly in the hollow cylinder allowing up-and-down linear (straight) motion Fit will not allow air or fluid in the cylinder

6. Mechanical System Crankshaft The crankshaft and connecting rod allow for the movement of the propeller.

7. Mechanical System Connecting Rod Attached to the throws With the crankshaft, they change the direction of the pistons into a circular motion

8. Mechanical System Valves A rocker arm regulates the opening and closing of each valve. Lobes or rings on a camshaft push the rocker arm

9. Step one (First Stroke) is called the intake stroke. Second step (Second Stroke) is the compression process. Third step (Third Stroke) is near the end of the compression stroke, the air and fuel mixture is ignited by an electric spark from the spark plug. The fourth step (Fourth Stroke) is called the exhaust stroke. Four – Stroke Cycle

10. Called intake stroke Piston moves down the cylinder creating vacuum Cam arrangement opens the intake valve Fuel and air drawn into the cylinder Four – Stroke Cycle – Stroke 1

11. Four – Stroke Cycle – Stroke 2 Piston moves up the cylinder Both valves closed Air and fuel compressed and pressure rises

12. Four – Stroke Cycle – Stroke 3 Air and fuel ignited by electrical spark Rise in temperature forces piston down

13. Four – Stroke Cycle – Stroke 4 Piston moves up forcing burned gas out of cylinder Burned gas transmitted to exhaust system

14. Four – Stroke Cycle – Process

15. Occurs at the same time in all cylinders, but not on the same step Ignition sequence of the cylinders called the firing order Four – Stroke Cycle – Process

16. Engine produces vast amount of heat Modern aircraft engines use an air cooling system The liquid cooling system on an aircraft works the same as does the cooling system on most automobiles. The coolant flows through the engine block and around cylinders. The liquid circulates through a system of pipes to a radiator. Cooling System

17. Must receive an electrical spark originating in the magneto Ignition System

18. Types of Reciprocating Engines In-line Engines Cylinders are located in a row, one behind the other Two classifications: Upright Inverted

19. Opposed Engines Two rows or banks of cylinders on each side of the crankshaft Rows directly opposite each other called horizontal opposed Types of Reciprocating Engines

20. V Engine “V” engine features two rows of cylinders set at an angle of about 45° Types of Reciprocating Engines

21. Radial Engine Crankshaft with only one throw Odd number of cylinders in each bank or row Maximum number of cylinders in each bank is nine Types of Reciprocating Engines

22. Most common form of fuels is hydrocarbons derived from petroleum Gasoline and kerosene offer several advantages: They are volatile Evaporate quickly High heat content which means high potential energy to be converted to kinetic energy as the fuel burns Do not deteriorate when stored over long periods of time Fuels Used in Reciprocating Engines

23. FLIGHT POWER Know basic engine principles. 1. Define a list of terms related to basic engine principles. 2. Describe the mechanical, cooling, and ignition systems of the reciprocating engines.