Types of Reciprocating Engines There are three main types of piston engines in current use: – Horizontally Opposed – Radial – In-Line Regional Gliding School.
Download ReportTranscript Types of Reciprocating Engines There are three main types of piston engines in current use: – Horizontally Opposed – Radial – In-Line Regional Gliding School.
Slide 1
Slide 2
Types of Reciprocating
Engines
There are three main types of piston
engines in current use:
– Horizontally Opposed
– Radial
– In-Line
Regional Gliding School
Slide 3
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
Slide 4
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
Slide 5
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
Slide 6
Confirmation Stage
NOTE: You must use the buttons in the Confirmation Stage
Slide 7
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
V6
Slide 8
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Slide 9
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Slide 10
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Slide 11
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 12
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
Slide 13
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Slide 14
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Slide 15
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Slide 16
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 17
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
Slide 18
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
Slide 19
Major Engine Components
Spark Plugs
Intake
Valve
Exhaust
Valve
Piston
Connecting Rod
Cylinder
Crankshaft
Regional Gliding School
Slide 20
The Four Stroke Cycle
Most piston engines operate on the four stroke cycle.
The piston moves through four strokes, two up and
two down, to complete the cycle.
The crankshaft makes two complete revolutions.
The four strokes are:
the induction (or intake) stroke,
the compression stroke,
the power (or combustion) stroke, and
the exhaust stroke.
Regional Gliding School
Slide 21
The Induction
(or Intake) Stroke
Intake valve is open.
Piston moves down.
Fuel/air mixture drawn into
combustion chamber
through intake valve.
Exhaust valve remains
closed.
Regional Gliding School
Slide 22
The Compression Stroke
Both valves are closed.
Piston moves up.
Mixture is compressed.
Compression ratio is
comparison of volume of
mixture with piston at the
bottom and volume with
piston at the top.
Regional Gliding School
Slide 23
The Power
(or Combustion) Stroke
Both valves are closed.
Compressed mixture is ignited
by spark plug.
Burning gas expands forcing
piston down.
Energy drives other three
strokes as well as useful work
(i.e.. turn propeller).
Regional Gliding School
Slide 24
The Exhaust Stroke
Exhaust valve is open.
Piston moves up.
Burnt gas is pushed out
through exhaust valve.
Intake valve remains
closed.
Regional Gliding School
Slide 25
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
Slide 26
Valve Lead
Timing the valve to open early.
Valve Lag
Timing the valve to close late.
Valve Overlap
Allowing both valves to remain
open at the same time.
Regional Gliding School
Slide 27
Valve Clearances
Valve 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.
Clearances too wide cause a loss of power and
excessive wear.
Clearances too close can warp the valves.
Regional Gliding School
Slide 28
Confirmation Stage
NOTE: You must use the buttons in the Confirmation Stage
Slide 29
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
Slide 30
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Let's try again...
Slide 31
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Slide 32
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 33
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 34
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
Slide 35
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I’m afraid that answer is incorrect
Let's try again...
Slide 36
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 37
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 38
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 39
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 early
B
Valve closes late
C
Both valves remain open
D
Both valves remain closed
Slide 40
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I’m afraid that answer is incorrect
Let's try again...
Slide 41
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 42
Flying Scholarship Program
I’m afraid that answer is incorrect
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Slide 43
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 44
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
Slide 2
Types of Reciprocating
Engines
There are three main types of piston
engines in current use:
– Horizontally Opposed
– Radial
– In-Line
Regional Gliding School
Slide 3
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
Slide 4
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
Slide 5
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
Slide 6
Confirmation Stage
NOTE: You must use the buttons in the Confirmation Stage
Slide 7
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
V6
Slide 8
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 9
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 10
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 11
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 12
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
Slide 13
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 14
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 15
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 16
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 17
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
Slide 18
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
Slide 19
Major Engine Components
Spark Plugs
Intake
Valve
Exhaust
Valve
Piston
Connecting Rod
Cylinder
Crankshaft
Regional Gliding School
Slide 20
The Four Stroke Cycle
Most piston engines operate on the four stroke cycle.
The piston moves through four strokes, two up and
two down, to complete the cycle.
The crankshaft makes two complete revolutions.
The four strokes are:
the induction (or intake) stroke,
the compression stroke,
the power (or combustion) stroke, and
the exhaust stroke.
Regional Gliding School
Slide 21
The Induction
(or Intake) Stroke
Intake valve is open.
Piston moves down.
Fuel/air mixture drawn into
combustion chamber
through intake valve.
Exhaust valve remains
closed.
Regional Gliding School
Slide 22
The Compression Stroke
Both valves are closed.
Piston moves up.
Mixture is compressed.
Compression ratio is
comparison of volume of
mixture with piston at the
bottom and volume with
piston at the top.
Regional Gliding School
Slide 23
The Power
(or Combustion) Stroke
Both valves are closed.
Compressed mixture is ignited
by spark plug.
Burning gas expands forcing
piston down.
Energy drives other three
strokes as well as useful work
(i.e.. turn propeller).
Regional Gliding School
Slide 24
The Exhaust Stroke
Exhaust valve is open.
Piston moves up.
Burnt gas is pushed out
through exhaust valve.
Intake valve remains
closed.
Regional Gliding School
Slide 25
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
Slide 26
Valve Lead
Timing the valve to open early.
Valve Lag
Timing the valve to close late.
Valve Overlap
Allowing both valves to remain
open at the same time.
Regional Gliding School
Slide 27
Valve Clearances
Valve 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.
Clearances too wide cause a loss of power and
excessive wear.
Clearances too close can warp the valves.
Regional Gliding School
Slide 28
Confirmation Stage
NOTE: You must use the buttons in the Confirmation Stage
Slide 29
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
Slide 30
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 31
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 32
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 33
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 34
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
Slide 35
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 36
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 37
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 38
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 39
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 early
B
Valve closes late
C
Both valves remain open
D
Both valves remain closed
Slide 40
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 41
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 42
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Slide 43
Flying Scholarship Program
That answer is correct.
Let's move on...
Slide 44
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