Regional Gliding School Types of Reciprocating Engines QThere

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Regional Gliding School

Regional Gliding School

Types of Reciprocating Engines QThere are three main types of piston engines in current

Types of Reciprocating Engines QThere are three main types of piston engines in current use: – Horizontally Opposed – Radial – In-Line Regional Gliding School

Horizontally Opposed • Two banks of cylinders which lie directly opposite to each other

Horizontally Opposed • Two banks of cylinders which lie directly opposite to each other in the horizontal plane. • Four, six or eight cylinders. • Design is flat with small frontal area (good visibility) and low drag production. • Most commonly used in general aviation. Regional Gliding School

Radial • Cylinders arranged radially. • Always an odd number of cylinders. • Crankshaft

Radial • Cylinders arranged radially. • Always an odd number of cylinders. • Crankshaft is short, compact and light. • Produces tremendous horsepower. • Poor shape increases parasite drag and reduces forward visibility. Regional Gliding School

In-Line • Cylinders are arranged side by side in a row. • Practical limit

In-Line • Cylinders are arranged side by side in a row. • Practical limit is six. • Any more cylinders and V, X or H-type in-line engines are used. • Two crankshafts side by side. • Some are inverted for better visibility. • Little drag but heavier engine and size limited. Regional Gliding School

Confirmation Stage NOTE: You must use the buttons in the Confirmation Stage

Confirmation Stage NOTE: You must use the buttons in the Confirmation Stage

Aero Engines Basic construction and the four stroke cycle Let's try a few review

Aero Engines Basic construction and the four stroke cycle Let's try a few review questions on Aero Engines: Question #1 - Regional Gliding School What type of engine is the most commonly used in general aviation? A Radial B In Line C Horizontally Opposed D V 6

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Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding School

Aero Engines Basic construction and the four stroke cycle Let's try a few review

Aero Engines Basic construction and the four stroke cycle Let's try a few review questions on Aero Engines: Question #2 - Regional Gliding School What is an disadvantage of using a radial engine? A Heavy crankshaft B Poor visibility C Short crankshaft D Size is limited

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding School

Construction of a Reciprocating Engine • Piston - Cylinder shaped object that moves up

Construction of a Reciprocating Engine • Piston - Cylinder shaped object that moves up and down. • Piston Rings - wrap around the piston and provide a seal between the piston and cylinder. • Connecting Rod - joins the piston to the crankshaft, which turns the propeller. • Cylinder Head - contains the inlet (intake) valve, exhaust valve and two spark plugs. Regional Gliding School

Construction of a Reciprocating Engine • Camshaft - turned by the crankshaft and operates

Construction of a Reciprocating Engine • Camshaft - turned by the crankshaft and operates the push rods and rocker arms. It turns at half the speed the crankshaft turns. • Magnetos - provide electrical current to ignite the Fuel/Air mixture through the distributor. • Intake Valve Ports - allow air to enter the cylinder and is connected to the carburetor where the air and fuel are mixed. • Exhaust Valve - connected to the exhaust pipe, which vents the exhaust fumes away from the cabin. Regional Gliding School

Major Engine Components Spark Plugs Intake Valve Exhaust Valve Piston Cylinder Connecting Rod Crankshaft

Major Engine Components Spark Plugs Intake Valve Exhaust Valve Piston Cylinder Connecting Rod Crankshaft Regional Gliding School

The Four Stroke Cycle ÊMost piston engines operate on the four stroke cycle. ÊThe

The Four Stroke Cycle ÊMost piston engines operate on the four stroke cycle. ÊThe piston moves through four strokes, two up and two down, to complete the cycle. ÊThe crankshaft makes two complete revolutions. ÊThe four strokes are: the induction (or intake) stroke, the compression stroke, the power (or combustion) stroke, and the exhaust stroke. Regional Gliding School

The Induction (or Intake) Stroke ÜIntake valve is open. ÜPiston moves down. ÜFuel/air mixture

The Induction (or Intake) Stroke ÜIntake valve is open. ÜPiston moves down. ÜFuel/air mixture drawn into combustion chamber through intake valve. ÜExhaust valve remains closed. Regional Gliding School

The Compression Stroke ÔBoth valves are closed. ÔPiston moves up. ÔMixture is compressed. ÔCompression

The Compression Stroke ÔBoth valves are closed. ÔPiston moves up. ÔMixture is compressed. ÔCompression ratio is comparison of volume of mixture with piston at the bottom and volume with piston at the top. Regional Gliding School

The Power (or Combustion) Stroke Ø Both valves are closed. Ø Compressed mixture is

The Power (or Combustion) Stroke Ø Both valves are closed. Ø Compressed mixture is ignited by spark plug. Ø Burning gas expands forcing piston down. Ø Energy drives other three strokes as well as useful work (i. e. . turn propeller). Regional Gliding School

The Exhaust Stroke Ø Exhaust valve is open. Ø Piston moves up. Ø Burnt

The Exhaust Stroke Ø Exhaust valve is open. Ø Piston moves up. Ø Burnt gas is pushed out through exhaust valve. Ø Intake valve remains closed. Regional Gliding School

Timing ¬The purpose of timing is to improve the performance of the engine. Valves

Timing ¬The purpose of timing is to improve the performance of the engine. Valves take time to open and close. ®Therefore they are timed to open early and close late in order not to waste any of the induction or exhaust stroke. Regional Gliding School

Valve Lead èTiming the valve to open early. Valve Lag èTiming the valve to

Valve Lead èTiming the valve to open early. Valve Lag èTiming the valve to close late. Valve Overlap èAllowing both valves to remain open at the same time. Regional Gliding School

Valve Clearances ÌValve clearance, or tappet clearance, is a space that must be provided

Valve Clearances ÌValve clearance, or tappet clearance, is a space that must be provided between the valve stem and rocker to allow for heat expansion of the metal. ÌClearances too wide cause a loss of power and excessive wear. ÌClearances too close can warp the valves. Regional Gliding School

Confirmation Stage NOTE: You must use the buttons in the Confirmation Stage

Confirmation Stage NOTE: You must use the buttons in the Confirmation Stage

Aero Engines Basic construction and the four stroke cycle Let's try a few review

Aero Engines Basic construction and the four stroke cycle Let's try a few review questions on Aero Engines: Question #3 - Regional Gliding School Name the second stroke in the four stroke engine? A Intake B Power C Compression D Exhaust

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Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

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Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding School

Aero Engines Basic construction and the four stroke cycle Let's try a few review

Aero Engines Basic construction and the four stroke cycle Let's try a few review questions on Aero Engines: Question #4 - Regional Gliding School During which stroke do the spark plugs fire? A Intake B Power C Compression D Exhaust

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Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding School

Aero Engines Basic construction and the four stroke cycle Let's try a few review

Aero Engines Basic construction and the four stroke cycle Let's try a few review questions on Aero Engines: Question #5 - Regional Gliding School What is the definition of valve lag? A Valve closes too early B Valve closes too late C Both valves remain open D Both valves remain closed

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . . Regional Gliding School

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding

Flying Scholarship Program That answer is correct. Let's move on. . . Regional Gliding School

Aero Engines Basic construction and the four stroke cycle Congratulations!! You have now completed

Aero Engines Basic construction and the four stroke cycle Congratulations!! You have now completed the Basic Construction and the Four Stroke Cycle lesson of the Aero Engines Module. Of course, this lesson is always available to you for future reference if required. You are now ready to move along to the next Aero Engines lesson you have not completed or to any other module you wish. You can advance to the Self Test Module if you feel ready to challenge the final exam. Good Luck! Regional Gliding School