Motor

Question 1

The highest pressure in a diesel engine cylinder normally occurs __________.

Answer 1

after TDC

Question 2

In a diesel engine, after ignition of the fuel occurs, but before the piston reaches TDC, there is little change in the cylinder __________.

Answer 2

volume

Question 3

Which statement about diesel engine combustion is true?

Answer 3

Maximum cylinder firing pressure is not developed until the piston passes TDC.

Question 4

The duration of the power event shown in the four cycle engine polar timing diagram is represented by how many crankshaft degrees of revolution? MO-0084

Answer 4

125 degrees

Question 5

In the illustrated polar timing diagram for a four-stroke cycle diesel engine, relative to crank degrees of travel with respect TDC or BDC as appropriate, when does the intake valve open? MO-0084

Answer 5

75 degrees before TDC

Question 6

In the illustrated polar timing diagram for a four-stroke diesel engine, relative to the number of crank degrees before or after TDC or BDC as appropriate, when does the intake valve close? MO-0084

Answer 6

45 degrees after BDC

Question 7

According to the illustrated polar timing diagram for a four- stroke cycle diesel engine, the exhaust valve is open for a duration of how many degrees of crank travel? MO-0084

Answer 7

320 degrees

Question 8

According to the illustrated polar timing diagram for a four- stroke cycle high speed diesel engine, the period of valve overlap occurs for a duration of how many degrees of crank travel? MO-0084

Answer 8

160 degrees

Question 9

The polar timing diagram shown in the illustration is of a four stroke cycle, high speed diesel engine, with fuel injection timing commencing at 10° BTDC. Approximately how many degrees will the crankshaft rotate from the point at which fuel injection begins to the point where the exhaust valves begin to open? MO-0084

Answer 9

135°

Question 10

Which segment of the two cycle engine diagram shown represents compression? MO-0037

Answer 10

I

Question 11

Which segment of the two cycle engine diagram shown in the illustration represents ‘supercharging’? MO-0037

Answer 11

III

Question 12

Which segment of the two cycle engine diagram shown in the illustration represents the exhaust event? MO-0037

Answer 12

IV

Question 13

Which segment of the two cycle engine diagram shown represents the power stroke? MO-0037

Answer 13

VI

Question 14

If point #1 in the diagram shown is the beginning of gas compression, which of the cycles listed is being illustrated? Illustration MO-0036

Answer 14

Diesel

Question 15

In the theoretical diesel cycle, shown in the illustration, which of the listed conditions normally takes place between points “3” and “4”? MO-0036

Answer 15

Expansion

Question 16

In the pressure-volume diagram shown in the illustration, curve ‘A-d’ indicates __________. MO-0035

Answer 16

combustion at approximately constant pressure

Question 17

In the pressure-volume diagram, shown in the illustration, the volume line is divided into 16 units indicating __________. MO-0035

Answer 17

a 16 to 1 compression ratio

Question 18

In the pressure-volume diagram, shown in the illustration, the volume line is divided into 16 units indicating __________. MO-0035

Answer 18

a 16 to 1 compression ratio

Question 19

In the pressure-volume diagram, shown in the illustration, what is indicated to have occurred by the line connecting points “d” and “e”? MO-0035

Answer 19

The combustion gases have expanded.

Question 20

In the pressure-volume diagram, shown in the illustration, what occurs between points “e” and “f”? MO-0035

Answer 20

Pressure in the cylinder decreases.

Question 21

In the pressure-volume diagram, shown in the illustration, what occurs between points “e” and “f”? MO-0035

Answer 21

Exhaust blow down occurs.

Question 22

In the pressure-volume diagram shown in the illustration, the atmospheric pressure line is indicated by line __________. MO-0035

Answer 22

C

Question 23

In the pressure-volume diagram shown in the illustration, fuel injection occurs at point __________. MO-0035

Answer 23

C

Question 24

Which of the bearings listed below is most widely used for the main and connecting rod bearings of a modern high-speed diesel engine?

Answer 24

Precision insert

Question 25

Babbitt is a metal alloy commonly used for lining __________.

Answer 25

Precision bearings

Question 26

Which of the following methods is used to securely fasten the Babbitt lining of a reduction gear bearing to its shell?

Answer 26

The Babbitt is centrifugally spun into the bearings or cast under a pressure head.

Question 27

Which of the following types of bearings are used as line shaft bearings?

Answer 27

Ring-oiled, Babbitt-faced, spherical seat, shell

Question 28

From the data given in the illustration, which pair of pistons listed are mounted on the same crank throw? MO-0004

Answer 28

3L/3R

Question 29

From the engine data given in the illustration, what is the swept volume of any one engine cylinder? MO-0004

Answer 29

4766 cubic inches

Question 30

From the engine data shown in the illustration, what would be the average piston speed if the engine were turning 400 RPM? MO-0004

Answer 30

1400 ft/min

Question 31

From the engine data given, after cylinder #1L fires, how many degrees of crankshaft rotation must take place before #4L cylinder fires? MO-0004

Answer 31

90°

Question 32

From the engine data given in the illustration, what is the full load air manifold pressure? MO-0004

Answer 32

15.22 psi

Question 33

The camshafts on the engine, shown in the illustration, operate at a speed equal to __________. MO-0005

Answer 33

one-half of the crankshaft speed

Question 34

Which of the following characteristics can be determined about the standby diesel engine shown in the illustration? MO-0005

Answer 34

The camshaft rotates at one half the engine speed.

Question 35

According to the diagram shown in the illustration, the lube oil system can best be described as a __________. MO-0007

Answer 35

wet sump system

Question 36

If the manufacturer's instructions do not state otherwise, which of the following progressions represent the best order for tightening the head bolts shown in the illustration? MO-0028

Answer 36

15372648

Question 37

Which of the indicator diagrams illustrated depicts the condition that should be corrected by retarding only the timing? MO-0029

Answer 37

A

Question 38

The instrument shown in the illustration would be used on a diesel engine to __________. MO-0031

Answer 38

take compression and firing readings

Question 39

On a main propulsion diesel engine, the instrument shown in the illustration would normally be attached to the __________. MO-0031

Answer 39

cylinder blow down valve

Question 40

Which area of the indicator diagram illustrated indicates the afterburning period in a diesel engine cylinder? MO-0033

Answer 40

K

Question 41

In the pressure-volume diagram, shown in the illustration, what is indicated to have occurred by the line connecting points "d" and "e"? MO-0035

Answer 41

the combustion gases have expanded

Question 42

The boiler shown in the illustration would be classed as __________. MO-0064

Answer 42

single-pass, fire- tube, scotch marine

Question 43

The illustration shown describes a _______. MO-0069

Answer 43

two cycle opposed piston diesel engine

Question 44

Which of the following statements would apply when checking the valve clearance of the unit shown in the illustration? MO-0074

Answer 44

Cold valve clearance is measured between components "C" and "D".

Question 45

When inspecting the valve mechanism shown in the illustration, normal maintenance would include __________. MO-0074

Answer 45

measuring the cold valve clearance between components "C" and "D"

Question 46

The device shown in the illustration is a __________. MO-0070

Answer 46

hydraulic lash adjuster

Question 47

The device shown has been removed from an exhaust valve bridge assembly. The function of the illustrated device is to __________. MO-0070

Answer 47

maintain valve lash adjustment

Question 48

The RPM of "D" is 500 and hobbed with 36 teeth. If gears "A", "B", and "C" have 72, 64, and 24 teeth respectively, the RPM of "A" in the gear train illustration is __________. MO-0088

Answer 48

93.75 RPM

Question 49

The RPM of "D" is 800 and hobbed with 38 teeth. If gears "A", "B", and "C" have 80, 62, and 20 teeth respectively, the RPM of "A" in the gear train illustration is __________. MO-0088

Answer 49

122.58 RPM

Question 50

In the illustration, If gear A has 72 teeth, gear B has 64 teeth, gear C has 24 teeth and gear D has 36 teeth, what is the RPM of the gear D if gear A is turning at 100 RPM? MO-0088

Answer 50

533.33 RPM

Question 51

The RPM of "A" is 100 and hobbed with 76 teeth. If gears "B", "C", and "D" have 60, 32, and 42 teeth respectively, the RPM of "D" in the gear train illustration is __________. MO-0088

Answer 51

339.29 RPM

Question 52

After a long period of operation, a wear ridge, caused by piston ring action, will develop near the top of the cylinder liner. This ridge must be removed during maintenance in order to prevent __________.

Answer 52

breaking of the rings, ring lands, or both during piston removal

Question 53

The ring lands on a large, low-speed, main propulsion diesel engine piston may crack due to __________.

Answer 53

insufficient ring groove clearance

Question 54

The proper location for journal bearing oil grooves is __________.

Answer 54

as a side relief where the two shells meet

Question 55

The part labeled "G", as shown in the illustration, is a __________. MO-0040

Answer 55

connecting rod bushing

Question 56

The part labeled "F" shown in the illustration, is the __________. MO-0040

Answer 56

bearing shell halves

Question 57

The part labeled "E", as shown in the illustration, is the __________.

Answer 57

connecting rod cap

Question 58

The illustration is of a/an __________. Illustration MO-0044

Answer 58

air driven starter motor assembly

Question 59

The Bendix drive on the starting motor illustrated is indicated by piece number __________. MO-0044

Answer 59

53

Question 60

In the illustration, pieces #31 and #29, have 16 and 55 teeth respectively. In order to start the engine, the Bendix drive must turn 3000 RPM. Therefore, the air motor assembly must rotate at __________. MO-0044

Answer 60

10312.5 RPM

Question 61

On the cylinder indicator diagram illustrated, the dotted line indicated as 'L' is describing the _________. Illustration MO-0033

Answer 61

cylinder pressure without injection

Question 62

Which area of the indicator diagram illustrated, indicates the ignition delay period in a diesel engine cylinder? Illustration MO-0033

Answer 62

J

Question 63

On the cylinder indicator diagram illustrated, the maximum rise in pressure occurs during the period labeled as ______. Illustration MO-0033

Answer 63

H

Question 64

In the illustration shown, if a crankcase explosion occurs in a diesel engine, which of the following will occur? MO-0105

Answer 64

Spring #11 will be compressed

Question 65

What is the purpose of the device shown in the illustration? MO-0105

Answer 65

Protect the crankcase from overpressure in the event of explosion.

Question 66

One method of determining crankshaft misalignment is by __________.

Answer 66

taking micrometer readings between the crank cheeks opposite the crankpin every 90° of crank angle rotation

Question 67

High-speed, multi-cylinder, diesel engines commonly use counterweights placed opposite to the crankpins to __________.

Answer 67

provide dynamic balance by equalizing centrifugal force

Question 68

The bearing shown in the illustration is designed to carry thrust when applied __________. Illustration MO-0001

Answer 68

right to left only

Question 69

The part labeled "C" of the illustrated bearing is called the __________. MO-0001

Answer 69

Cage

Question 70

The part labeled "A" of the illustrated bearing is called the __________. MO-0001

Answer 70

inner race

Question 71

Valve '1', as shown in the illustration when, should be operated when __________. Illustration MO-0077

Answer 71

entering or departing port.

Question 72

As shown in the illustration, the viscosimeter would be used to directly control the output of which of the following components? Illustration MO-0077

Answer 72

Final heaters.

Question 73

Fuel injection pumps using the port and helix metering principle requires the use of a __________.

Answer 73

lapped plunger and barrel

Question 74

The purpose of the delivery check valve used in a diesel fuel injection jerk pump is to __________.

Answer 74

assist in a quick cutoff of fuel injection