Reciprocating Engines

Question 1

How are reciprocating engines classified?

Answer 1

•Cylinder arrangement and number
•Cooling method
•Number of strokes per cycle

Question 2

What are the 4 most common cylinder arrangements?

Answer 2

•In-line
•V-Type
•Radial
•Opposed

Question 3

With a rotary radial engine, the ______ is mounted directly to the airframe with propeller mounted to the crankcase and cylinders spinning around.

Answer 3

Crankshaft

Question 4

Radial engines are well cooled but have poor _____ ______ and bad ____ ____.

Answer 4

Poor engine control
Bad torque rolling

Question 5

What are the 2 types of cooling classifications?

Answer 5

Air & Liquid

Question 6

2-stroke engines have a power pulse every _____ degrees of crankshaft rotation.

Answer 6

360

*not as fuel efficient

Question 7

4 stroke engines have a power pulse every _____ degrees of crankshaft rotation.

Answer 7

720

*more fuel efficient but less powerful

Question 8

What are the identification letter prefixes for:
O -
G -
S -
T -
I -
A -
H -
V -
L -
L -
R -

Answer 8

Opposed
Geared
Supercharged
Turbocharged
I = Fuel Injected
Horizontal
Vertical
L = Left rotation
L = Liquid Cooled
Radial

Question 9

Maintenance must be done in accordance with the ______

Answer 9

Manufactures Maintenance

Question 10

What is the color coding for Chrome cylinders?

Answer 10

Orange

Question 11

What is the color coding for nitrided cylinders?

Answer 11

Blue

Question 12

What is the cylinder barrel skirt?

Answer 12

Extends beyond the flange into the crankcase

Question 13

What does the skirt do?

Answer 13

Prevents oil from running into the cylinder

Question 14

What is housed in the cylinder head?

Answer 14

The intake and exhaust valves, valve guides, valve seats and rocker arms as well as the spark plug holes

Question 15

What are intake valves ground at?

Answer 15

ground at 30 degrees

Question 16

What are exhaust valves on high powered engines filled with?

Answer 16

Metallic Sodium

Question 17

What are exhaust valves normally ground at?

Answer 17

Ground at 45 degree angle

Question 18

What are 5 types of Pistons?

Answer 18

Flat
Recessed
Concave
Dome
Truncated Cone

Question 19

Why do piston rings have gaps at the ends?

Answer 19

To allow for expansion at operating temperatures

Question 20

What is a valve lifter?

Answer 20

Also called a Tappet
Transmits force from camshaft to the push rod

Question 21

2 types of valve lifters:

Answer 21

Hydraulic or Solid

Question 22

What do push rods do?

Answer 22

Transmits force from lifter to rocker arm

Question 23

What do rocker arms do?

Answer 23

Transmits force from pushrod to valve

Question 24

What is found in the accessory section?

Answer 24

Mounting Pads
Pumps
Starter
Generator
Magnetos

Question 25

What are bearings?

Answer 25

A cylindrical surface that supports another surface for freedom of rotation along an axis

Question 26

what are 3 styles of bearings?

Answer 26

Plain Roller Ball

Question 27

What is the most common bearing?

Answer 27

Plain

Question 28

What are 4 parts of the crankshaft?

Answer 28

Main Journal Crankpin Crank cheek or arm Counterweights

Question 29

What are 3 reasons crankpins are hollow?

Answer 29

Reduces weight Passage for oil Sludge chamber

Question 30

What is the purpose of counterweights?

Answer 30

Provide static balance

Question 31

What is the main purpose of a dynamic damper?

Answer 31

To relieve whip and vibration

Question 32

What do connecting rods do?

Answer 32

Connect the piston and crank throw (H or I beam shape)

Question 33

What is Charle's law?

Answer 33

The pressure of a confined gas is directly proportional to its absolute temperature

Question 34

During each stroke, the crankshaft travels ____ degrees

Answer 34

180 1 full revolution is 360 degrees

Question 35

What are the 4 strokes?

Answer 35

Intake Compression Power Exhaust

Question 36

What're the 5 events?

Answer 36

Intake Compression Ignition Power Exhaust

Question 37

3 types of horsepower:

Answer 37

Indicated Brake Friction

Question 38

When calculating Indicated Horsepower, What does PLANK mean?

Answer 38

• P= indicated mean effective pressure (IMEP) • L= length of stroke in feet • A = area of the piston head in sq Inches • N = number of power strokes per min, per cylinder • K = number of cylinders

Question 39

What is brake horsepower?

Answer 39

The actual amount of power delivered to the propeller shaft (85-90% of indicated HP)

Question 40

What is friction horsepower?

Answer 40

Horsepower used by the engine to overcome the friction of moving parts (10-15% of indicated HP)

Question 41

What is detonation?

Answer 41

Uncontrolled, explosive combustion -High cylinder temps -Rough-running engine -Power loss -Damages, destroys engines

Question 42

What is preignition?

Answer 42

Combustion starts too early Ignition before spark

Question 43

Preignition and detonation can cause what?

Answer 43

Engine roughness High operating temps

Question 44

Does the intake or exhaust side of the cylinder have more cooling fins?

Answer 44

Exhaust

Question 45

What is it called when the intake valve opens early during the exhaust cycle and the escaping fumes ignite with the fuel?

Answer 45

Backfiring

Question 46

One Kilowatt is equal to how many watts?

Answer 46

1000 watts