Diesel/Motor Plants Flashcards
A Kingsbury, or pivot shoe type thrust bearing, can bear much greater loads per square inch of working surface than can parallel surface bearings because provisions are made in the Kingsbury bearing __________.
(a) for automatically adjusting clearances to the correct value when wear occurs
(b) for adjusting the filler piece thickness behind the pivotal-shoes to give a more accurate fit
(c) to allow the leveling plates to pivot on the collar when thrust loads are applied
(d) for the shoes to tilt slightly, thereby allowing the formation of a wedge shaped oil film under a thrust load
(d) for the shoes to tilt slightly, thereby allowing the formation of a wedge shaped oil film under a thrust load
Which component of a kingsbury thrust bearing assembly transmits the thrust from the line shaft to the oil film and shoes?
(a) Collar
(b) Lower leveling plate
(c) Upper leveling plate
(d) Base ring
(a) Collar
A four cylinder, four stroke/cycle, single acting diesel engine has a 740 mm bore and a 1500 mm stroke. What indicated power will be developed if the average mean effective pressure is 18 kg/cm2 at a speed of 90 RPM?
(a) 3416 kW
(b) 4644 kW
(c) 7296 kW
(d) 9290 kW
(a) 3416 kW
1764 x 430.08 x 1.5 x 0.75 x 4 = 3414 kW
or 853.5 kW/cyl
18kg/cm2 EMP = 1764kPa (18 x 1764) 740mm bore = 430.08m2 (pi x 370^2 / 1000) 1500mm stroke = 1.5m (1500 / 1000) 90 RPM, 4 stroke = 0.75 (90 / 2 / 60) 4 cylinders
An eight cylinder, four stroke/cycle, single acting diesel engine has a 650 mm bore and a 1400 mm stroke. What will be the developed indicated metric horsepower if the average mean effective pressure is 30 kg/cm2 at a speed of 100 RPM?
(a) 1689 kW
(b) 9,111 kW
(c) 12,388 kW
(d) 24,776 kW
(b) 9,111 kW
30kg/cm2 EMP = 2940 kpa (30 x 98)
650mm bore = area of 331.83m2 (pi x 325^2 / 1000)
1400mm stroke = 1.4m (1400 / 1000)
100RPM, 4 stroke = .833 power strokes/sec (100 / 2 / 60)
8 cylinders
2940 x 331.83 x 1.4 x .833 x 8 = 9101.77kW
The average pressure exerted on a piston during each power stroke is termed __________.
(a) indicated horsepower
(b) mean effective pressure
(c) exhaust back pressure
(d) compression pressure
(b) mean effective pressure
The most important factor in engine performance is the actual power output at the end of the crankshaft available for doing work. This is known as __________.
(a) indicated horsepower
(b) brake horsepower
(c) net horsepower
(d) friction horsepower
(b) brake horsepower
Cooling the intake air supplied to a diesel engine will __________.
(a) reduce mean effective pressure
(b) decrease average compression ratio
(c) decrease air charge density
(d) increase peak power output
(d) increase peak power output
A seven cylinder, 2-stroke/cycle, single acting diesel engine has a 750 mm bore and a 2000 mm stroke. What indicated power will be developed if the average mean effective pressure is 14.8 kg/cm2 at a speed of 96 RPM? A 1,959 kW B 3,906 kW C 14,363 kW D 28,726 kW
C 14,363 kW
14.8 kg/cm2 = 1450.2m2 (14.8 x 98) 750 mm bore = 441.786 (pi x 375^2 / 1000) 2000 mm stroke = 2m (2000 / 1000) 96 RPM, 2 stroke = 1.6 (96 / 60) 7 cylinders
1450.2 x 441.786 x 2 x 1.6 x 7 / 1000 = 14,351 kW
A Tier 2 V-16 Engine, four stroke/cycle single acting diesel engine has a 145mm bore and a 172mm stroke. What will be the indicated horsepower if the mean effective pressure is 19.4kg/cm2 at a speed of 1900 RPM?
1367.43 kW
19.4kg/cm2 MEP = 1901.2 (19.2 x 98)
145mm bore = 16.51m2 (pi x 72.5^2 / 1000)
172mm stroke = 0.172m (172 / 1000)
1900 RPM, 4 stroke = 15.83 (1900 / 2 / 60)
16 cylinders
1901.2 x 16.51 x 0.172 x 15.83 x 16 / 1000 = 1367.43
The heat exchanger plates, used in the device shown in the illustration, are produced from which of the listed materials? Illustration MO-0110 A Titanium B Copper C Anodized aluminum D Phosphor bronze
A Titanium
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? A 75 degrees B 100 degrees C 180 degrees D 320 degrees
D 320 degrees
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? A 75 degrees B 125 degrees C 160 degrees D 320 degrees
C 160 degrees
In the pressure-volume diagram, shown in the illustration, the volume line is divided into 16 units indicating __________. Illustration MO-0035
(a) a cylinder volume of 166 cubic inches
(b) compression pressure is 1600 PSI
(c) a 16 to 1 compression ratio
(d) 16° of crankshaft motion between lines A and B
(c) a 16 to 1 compression ratio
In the pressure-volume diagram shown in the illustration, curve ‘A-d’ indicates __________. Illustration MO-0035
(a) combustion at approximately constant pressure
(b) opening of exhaust valves
(c) fuel injection after dribble
(d) start of fuel injection
(a) combustion at approximately constant pressure
In the pressure-volume diagram, shown in the illustration, what is indicated to have occurred by the line connecting points ‘d’ and ‘e’? Illustration MO-0035
(a) The combustion gases have expanded.
(b) The crankshaft has rotated 90°.
(c) Pressure and volume have increased.
(d) The fuel/air charge is compressed.
(a) The combustion gases have expanded.
In the pressure-volume diagram, shown in the illustration, what occurs between points “e” and “f”? Illustration MO-0035
(a) The exhaust valve closes.
(b) The intake ports close.
(c) Pressure in the cylinder decreases.
(d) Volume in the cylinder decreases.
(c) Pressure in the cylinder decreases.
In the pressure-volume diagram shown in the illustration, fuel injection occurs at point __________. Illustration MO-0035
(a) e
(b) d
(c) f
(d) c
(d) c
Which segment of the two cycle engine diagram shown represents the power stroke? MO-0037 A I B VI C V D IV
B VI
Which segment of the two cycle engine diagram shown in the illustration represents 'supercharging'? MO-0037 A I B II C III D IV
C III
Which segment of the two cycle engine diagram shown in the illustration represents the exhaust event? MO-0037 A I B II C III D IV
D IV
Which segment of the two cycle engine diagram shown represents compression? MO-0037 A I B II C III D IV
A I
In the theoretical diesel cycle, shown in the illustration, which of the listed conditions normally takes place between points "3" and "4"? MO-0036 A Compression B Combustion-constant volume C Combustion-constant pressure D Expansion
D Expansion
If the compression ratio is increased on any diesel engine, __________.
(a) the expansion ratio will decrease
(b) combustion will be slowed down
(c) thermal efficiency will decrease
(d) thermal efficiency will increase
(d) thermal efficiency will increase
The ratio of the brake horsepower to the indicated horsepower of a diesel engine is its __________.
(a) thermal efficiency
(b) mechanical efficiency
(c) brake thermal efficiency
(d) volumetric efficiency
(b) mechanical efficiency
Precision engine bearing inserts are manufactured with a small portion of the bearing ends extending beyond the bearing housing or caps. This design provides for positive seating and is commonly referred to as bearing \_\_\_\_\_\_\_\_\_\_ . A clearance B crush C lap or lead D offset
B crush
Bearing ‘crush’ as applied to diesel engine main bearings, will result in __________ .
A positive seating of the bearings in their housings
B above normal operating temperatures
C damage to the journals
D damage to the bearings
A positive seating of the bearings in their housings
What is the function of the main thrust bearing?
(a) Prevents lateral movement of the slow speed gear.
(b) Transmits propeller thrust to the hull.
(c) Keeps spring bearings in line.
(d) Prevents main reduction gear axial movement.
(b) Transmits propeller thrust to the hull.
On a large diesel engine installation, crankshaft axial alignment is maintained by the __________.
(a) piston rod guides
(b) engine thrust bearing
(c) crosshead bearing
(d) main shaft flexible coupling
(b) engine thrust bearing
From the engine data given in the illustration, what is the swept volume of any one engine cylinder? MO-0004 A 182 cubic inches B 2800 cubic inches C 4766 cubic inches D 5712 cubic inches
C 4766 cubic inches
Bore = 17" Area = pi x 8.5^2 = 227 sq. in. Stroke = 21" Vol = 227 x 21 = 4767 cu. in.
From the engine data shown in the illustration, what would be the average piston speed if the engine were turning 400 RPM? A 1300 ft/min B 1400 ft/min C 1450 ft/min D 1500 ft/min
B 1400 ft/min
2 x 21 = 42
42 x 400 = 16,800 in
16,800 / 12 = 1400 ft/min
The camshafts on the engine, shown in the illustration, operate at a speed equal to \_\_\_\_\_\_\_\_\_\_ . MO-0005 A twice the crankshaft speed B the crankshaft speed C one-half of the crankshaft speed D proportionate to the crankshaft speed
C one-half of the crankshaft speed
[The engine depicted in MO-0005 is a four-stroke.]
From the engine data given in the illustration, what is the swept volume of any one engine cylinder? MO-0004 A 182 cubic inches B 2800 cubic inches C 4766 cubic inches D 5712 cubic inches
C 4766 cubic inches
Bore = 17" Area = pi x 8.5^2 = 227 sq. in. Stroke = 21" Vol = 227 x 21 = 4767 cu. in.
From the engine data shown in the illustration, what would be the average piston speed if the engine were turning 400 RPM? MO-0004 A 1300 ft/min B 1400 ft/min C 1450 ft/min D 1500 ft/min
B 1400 ft/min
2 x 21 = 42
42 x 400 = 16,800 in
16,800 / 12 = 1400 ft/min
From the data given in the illustration, which pair of pistons listed are mounted on the same crank throw? MO-0004 A 1L/8R B 3R/1L C 5R/7L D 3L/3R
D 3L/3R
The camshafts on the engine, shown in the illustration, operate at a speed equal to \_\_\_\_\_\_\_\_\_\_ . MO-0005 A twice the crankshaft speed B the crankshaft speed C one-half of the crankshaft speed D proportionate to the crankshaft speed
C one-half of the crankshaft speed
[The engine depicted in MO-0005 is a four-stroke.]
The instrument shown in the illustration would be used on a diesel engine to __________. Illustration MO-0031
(a) measure cylinder compression or firing pressures
(b) balance exhaust gas temperature readings
(c) measure exhaust gas pressure
(d) measure concentration of chromate in jacket water
(a) measure cylinder compression or firing pressures
Which area of the indicator diagram illustrated, indicates the afterburning period in a diesel engine cylinder? Illustration MO-0033
(a) J
(b) H
(c) K
(d) G
(c) K
Which area of the indicator diagram illustrated, indicates the afterburning period in a diesel engine cylinder? Illustration MO-0033
(a) J
(b) H
(c) K
(d) G
(c) K
The illustration shown describes a _______. MO-0069
(a) four cycle opposed cylinder diesel engine
(b) four cycle opposed piston diesel engine
(c) two cycle opposed cylinder diesel engine
(d) two cycle opposed piston diesel engine
(d) two cycle opposed piston diesel engine
Which of the following statements would apply when checking the valve clearance of the unit shown in the illustration? Illustration MO-0074
(a) The valve is mechanically adjusted at point “D”.
(b) The valve is mechanically adjusted at point “E”.
(c) Tappet clearance is measured between points “A” and “B”.
(d) Cold valve clearance is measured between components “C” and “D”.
(d) Cold valve clearance is measured between components “C” and “D”.
The RPM of gear "D" is 900 and it is hobbed with 48 teeth. If gears "A", "B", and "C" have 88, 66, and 22 teeth respectively, the RPM of gear "A" in the gear train illustration is \_\_\_\_\_\_\_\_\_\_ . MO-0088 A 75.00 RPM B 163.64 RPM C 100.00 RPM D 675.00 RPM
B) 163.64 RPM
D:B gear ratio = 66/48 = 1.375:1
A:C gear ratio = 88/22 = 4:1
- If “D” rotates at 900 RPM, “B” will rotate at 654.54 RPM (900 / 1.375)
- Because “C” is connected to the same shaft as “B,” “C” will also rotate at 654.54 RPM
- “A” will then rotate at 163.64 (654.54 / 4)
The RPM of gear “A” is 120 and it is hobbed with 48 teeth. If gears “B,” “C” and “D” have 12, 36, and 24 teeth respectively, the RPM of gear “D” in the gear train illustration is __________ . MO-0088
80 RPM
A:C gear ratio = 48/36 = 1.333
B:D gear ratio = 12/24 = 0.5
- If “A” rotates at 120 RPM, “C” will rotate at 160 RPM (120 x 1.333)
- Because “C” is connected to the same shaft as “B,” “B” will also rotate at 160 RPM
- “D” will then rotate at 80 RPM (160 x 0.5)
The RPM of "D" is 900 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 A 168.75 RPM B 112.50 RPM C 100.00 RPM D 800.00 RPM
A) 168.75 RPM
D:B = 36/64 = 0.5625 C:A = 24/72 = 0.3333
- If “D” rotates at 900 RPM, “B” will rotate at 506.25 RPM (900 x 0.5625)
- Because “C” is connected to the same shaft as “B,” “C” will also rotate at 506.25 RPM
- “A” will then rotate at 168.75 (506.25 x 0.3333)
The RPM of "A" is 150 and hobbed with 86 teeth. If gears "B", "C", and "D" have 66, 22, and 48 teeth respectively, the RPM of "D" in the gear train illustration is \_\_\_\_\_\_\_\_\_\_ . MO-0088 A 806.25 RPM B 89.58 RPM C 618.75 RPM D 68.75 RPM
A) 806.25 RPM
A:C gear ratio = 86/22 = 3.91
B:D gear ratio = 66/48 = 1.375
- If “A” rotates at 150 RPM, “C” will rotate at 596.5 RPM (150 x 3.91)
- Because “C” is connected to the same shaft as “B,” “B” will also rotate at 596.5 RPM
- “D” will then rotate at 806.4 RPM (596.5 x 1.375)
The fuel injector for the diesel engine shown in the illustration, is identified as _________. MO-0122
(a) “H”
(b) “19”
(c) “M”
(d) “Z”
(b) “19”
What type of fuel injector is installed in the diesel engine shown in the illustration? MO-0122
(a) Solid jerk
(b) Air Assisted
(c) Unit
(d) Common rail
(c) Unit
Item “17” in the illustration is the dipstick. When should the length of the dipstick be changed? MO-0122
(a) In most situations this would never be done.
(b) If the operating oil level of the engine is consistently below normal, it will be necessary to use a longer dip stick.
(c) When changing the oil in an operating engine, it may become necessary to use a longer stick to obtain the exact location of the oil level at all times.
(d) If sludge buildup on the bottom of the pan becomes excessive, it will become necessary to shorten the dipstick to accommodate for the false oil level reading.
(a) In most situations this would never be done.
What is the function of component “13” shown in the illustration? MO-0122
(a) The inlet jumper directs cooling water to the cylinder liner.
(b) The device delivers the oil for piston cooling, in addition to liner lubrication.
(c) The water pipe is the mechanism in which the ‘shaker’ method of piston cooling is
accomplished.
(d) The sample tube monitors the cylinder for evidence of piston blow by.
(b) The device delivers the oil for piston cooling, in addition to liner lubrication.
In the cylinder head illustrated, the valves are seated by __________. MO-0013
(a) gas pressure
(b) valve springs
(c) air pressure
(d) a rocker arm not shown
(b) valve springs
Which of the listed cylinder head design features is shown in the illustration? MO-0013
(a) The valve cages are provided for the exhaust valves.
(b) The engine is equipped with a dry liner.
(c) A gas-tight seal is provided by a gasket between the cylinder head and cylinder liner.
(d) The engine cylinder head is fitted with replaceable valve seats.
(d) The engine cylinder head is fitted with replaceable valve seats.
The speed of the camshaft in a two-stroke/cycle diesel engine, running at 950 RPM, is __________.
(a) 475 RPM
(b) 950 RPM
(c) 1900 RPM
(d) 2400 RPM
(b) 950 RPM
Which construction detail is apparent in the connecting rod and piston assembly shown in the illustration? MO-0011
(a) The piston is designed with a heat dam.
(b) It is a fork assembly.
(c) The piston is water cooled.
(d) The wrist pin is free floating.
(a) The piston is designed with a heat dam.
Which of the following statements is correct concerning the connecting rod and piston assembly shown in the illustration? MO-0011
(a) The piston is free to rotate on the carrier thrust washer.
(b) The piston pin is bolted to the connecting rod.
(c) The piston has a heat dam.
(d) All of the above.
(d) All of the above.
The upper piston compression ring can be protected from overheating by a heat dam. This physical concept is shown
in the illustration and designated by the figure lettered as __________. MO-0017
(a) A
(b) B
(c) C
(d) D
(c) C
[C, E and F all have heat dams.]
During the power stroke, the side thrust of a trunk type piston is a result of the angle __________.
(a) formed by the connecting rod and the cylinder center line
(b) formed by the piston in relation to the piston pin
(c) between the crank arm and crankpin
(d) between the master and link connecting rods
(a) formed by the connecting rod and the cylinder center line
Which of the following represents the diesel engine camshaft shown in the illustration and its relative rotating speed? MO-0122
(a) “B” is the camshaft and it rotates at one half of the crankshaft speed.
(b) “T” is the camshaft and its speed equals crankshaft speed.
(c) “Y” is the main camshaft drive and rotates at crankshaft speed.
(d) “B” is the camshaft and its rpm will match that of the flywheel.
(d) “B” is the camshaft and its rpm will match that of the flywheel.
[Two stroke engine.]
The diesel engine rocker arms shown in the illustration serve to __________. MO-0122
(a) open the intake and exhaust valves
(b) operate the exhaust and starting valves
(c) convert rotational energy to reciprocating pressures
(d) open the exhaust valves and operate the unit injectors
(d) open the exhaust valves and operate the unit injectors
The rocker arms of the diesel engine shown in the illustration are indicated by __________. MO-0122
a) “C”
b) “D”
c) “B”
d) “C” and “Y”
d) “C” and “Y”
Device “E” shown in the illustration is known as the __________. MO-0122
a) fuel manifold
b) lube oil manifold
c) over speed trip shaft
d) extrusion tube assembly
a) fuel manifold
The diesel engine connecting rods shown in the illustration are distinctively named __________. Illustration MO-0122
(a) fork and blade
(b) male and female
(c) hook and nail
(d) left hand and right hand
(a) fork and blade
The part labeled “G”, as shown in the illustration, is a __________. MO-0040
(a) connecting rod cap
(b) bearing shell
(c) connecting rod bushing
(d) piston bushing
(c) connecting rod bushing
The illustration is of a/an __________. Illustration MO-0044
(a) air driven starter motor assembly
(b) power take-off driven, vane type, air compressor
(c) air driven DC generator
(d) battery powered, electric motor driven vane type, hydraulic pump
(a) air driven starter motor assembly
Crank web deflection readings will give a positive indication of __________.
(a) worn main bearing journals
(b) crankpin misalignment
(c) slack thrust bearings
(d) bearing shells shim dimensions
(a) worn main bearing journals
Which instrument is used to take crankshaft deflection readings?
a) Trammel gage
b) Dial type outside micrometer
c) Dial type inside micrometer
d) Gage block
c) Dial type inside micrometer
Which of the following problems could develop due to the accumulation of oil vapors in the crankcase of a diesel engine?
(a) Crankcase explosion
(b) Poor fuel economy
(c) Reduced lubrication
(d) Combustion knock
(a) Crankcase explosion
Which of the following problems could develop due to the accumulation of oil vapors in the crankcase of a diesel engine?
(a) Reduced lubrication
(b) Poor fuel economy
(c) Combustion knock
(d) Crankcase explosion
(d) Crankcase explosion
Crankcase explosions in propulsion diesel engines result from __________.
(a) the splashing of lubrication oil by the crankshaft
(b) the dilution of crankcase oil with particles of combustion
(c) broken fuel lines spraying oil on the crankcase
(d) the ignition of unburned fuel and air in the crankcase
(d) the ignition of unburned fuel and air in the crankcase
What is the purpose of the device shown in the illustration? MO-0105
A Regulate lube oil pressure in a diesel engine.
B Protect the crankcase from overpressure in the event of explosion.
C Utilize exhaust gas pressure to supercharge a diesel engine.
D Secure the engine in the event of dangerous overspeed.
B Protect the crankcase from overpressure in the event of explosion.
In the illustration shown, if a crankcase explosion occurs in a diesel engine, which of the following will occur? MO-0105
A Piece #2 will move to the right
B Piece #5 will rotate counterclockwise as viewed from the right
C Piece #7 will move to the left
D Spring #11 will be compressed
D Spring #11 will be compressed
The illustration shown describes the _______. MO-0033
a) cylinder pressure through 90 degrees of crankshaft rotation
b) cylinder pressure through 180 degrees of crankshaft rotation
c) compression and power event in a two cycle diesel
d) intake and exhaust event in a four cycle diesel
c) compression and power event in a two cycle diesel
One method of determining crankshaft misalignment is by __________.
(a) laying a straight edge across the crank webs at the crankpin and measuring the distance to the crankpin in two places
(b) taking micrometer readings between the crank cheeks opposite the crankpin every 90° of crank angle rotation
(c) measuring the crank drop on either side of each crank throw while the crankshaft is slowly rotated through one revolution
(d) rotating the crankshaft through one revolution, pausing each 90° of rotation to measure bearing clearances, top and bottom
(b) taking micrometer readings between the crank cheeks opposite the crankpin every 90° of crank angle rotation
On the cylinder indicator diagram illustrated, the dotted line indicated as ‘L’ is describing the _________. Illustration MO-0033
(a) cylinder pressure without injection
o (b) firing pressure at 90 degrees crank angle o (c) beginning of compression
o (d) power expansion curve
(a) cylinder pressure without injection
Which area of the indicator diagram illustrated, indicates the ignition delay period in a diesel engine cylinder? Illustration MO-0033
(a) G
(b) H
(c) J
(d) K
(c) J
On the cylinder indicator diagram illustrated, the maximum rise in pressure occurs during the period labeled as ______. Illustration MO-0033
(a) J
(b) K
(c) G
(d) H
(d) H
On the cylinder indicator diagram illustrated, the dotted line indicated as ‘L’ is describing the _________. Illustration MO-0033
(a) power expansion curve
(b) beginning of compression
(c) cylinder pressure without injection
(d) firing pressure at 90 degrees crank angle
(c) cylinder pressure without injection
Which area of the indicator diagram illustrated, indicates the afterburning period in a diesel engine cylinder? Illustration MO-0033
(a) J
(b) H
(c) K
(d) G
(c) K
According to the diagram shown in the illustration, the lube oil system can best be described as a __________. Illustration MO-0007
(a) bypass system
(b) dry sump system
(c) wet sump system
(d) shunt system
(c) wet sump system
High-speed, multi-cylinder, diesel engines commonly use counterweights placed opposite to the crankpins to __________.
(a) prevent bearing loads
(b) provide dynamic balance by equalizing centrifugal force
(c) counteract inertia forces
(d) provide a balance of rocking couples around the crankshaft
(b) provide dynamic balance by equalizing centrifugal force
The bearing shown in the illustration is designed to carry thrust when applied __________. MO-0001
(a) left to right only
(b) right to left only
(c) in either direction
(d) the bearing pictured is not designed to carry thrust
(b) right to left only
The purpose of the flywheel is to __________ .
A provide energy to operate the engine between power impulses
B neutralize the primary inertia force of the crankshaft
C reduce the shock of starting loads on the main bearings
D prevent the engine from operating at critical speed
A provide energy to operate the engine between power impulses
The flywheel reduces speed fluctuations by \_\_\_\_\_\_\_\_\_\_ . A maintaining a constant rack setting B storing kinetic energy C maintaining equal exhaust pressure D maintaining even camshaft speed
B storing kinetic energy
The part labeled "A" of the illustrated bearing is called the \_\_\_\_\_\_\_\_\_\_ . A thrust ring B outer race C inner race D cage
C inner race
The part labeled "B" of the illustrated bearing is called the \_\_\_\_\_\_\_\_\_\_ . A thrust ring B outer race C inner race D cage
B outer race
The part labeled "C" of the illustrated bearing is called the \_\_\_\_\_\_\_\_\_\_ . A thrust ring B outer race C inner race D cage
D cage
The diesel engine component labeled “1”, shown in the illustration is called a/an __________. Illustration MO-0122
(a) external thread
(b) exhaust valve spring
(c) inlet valve spring
(d) conical speed/surge prevention device
(b) exhaust valve spring
The pinion of an auxiliary diesel electric starting motor normally engages the flywheel ring gear by means of a/an __________.
(a) magnetic type coupling
(b) automatic follow-up
(c) muff coupling and release
(d) Bendix drive or similar mechanism
(d) Bendix drive or similar mechanism
In a Bendix starter drive, the pinion engagement with the flywheel ring gear is initiated by __________.
(a) Bendix spring pressure
(b) starter drive shaft rotation
(c) a differential spring
(d) solenoid throw out action
(b) starter drive shaft rotation
In a normally operating diesel engine, the main source of lubricating oil contamination in the crankcase is a result of the __________.
(a) air when no air cleaners are used
(b) combustion byproducts removed from the cylinder walls
(c) condensation of water vapors
(d) metal particles loosened by wear
(b) combustion byproducts removed from the cylinder walls
Lube oil filters remove contaminants more efficiently if the oil being filtered is __________.
(a) under high pressure
(b) under low pressure
(c) heated to reduce viscosity
(d) cooled to increase viscosity
(c) heated to reduce viscosity
The piston pin shown in the illustration should be classified as __________. MO-0011
a) fixed
b) semi-floating
c) full floating
d) anchored
b) semi-floating
The part labeled “F” shown in the illustration, is the __________. MO-0040
a) connecting rod cap
b) bearing shell halves
c) connecting rod bushing
d) piston pin bushing
b) bearing shell halves
The part labeled “E”, as shown in the illustration, is the __________. MO-0040
a) bearing shell
b) connecting rod bushing
c) piston pin bushing
d) connecting rod cap
d) connecting rod cap
Which of the listed conditions is most likely to cause a crankcase explosion?
a) A high cooling water temperature
b) Fuel dilution of the lube oil
c) Excessive engine speeds
d) Improper lube oil viscosity
b) Fuel dilution of the lube oil
Air motors used for starting some auxiliary diesel engines are generally the type known as a/an __________.
(a) vane motors
(b) accumulator motors
(c) plunger motors
(d) gear motors
(a) vane motors
Hydraulic starters are installed on many lifeboat diesel engines instead of comparable air start systems, because __________.
(a) hydraulic starters are the least expensive of all starting systems
(b) the system does not require high pressure piping
(c) hydraulic systems turn diesel engines at higher rates of speed than air starters
(d) the system can be manually recharged
(d) the system can be manually recharged
Starting systems for large, direct reversing, main propulsion diesel engines are usually __________.
(a) hydraulic starting motor
(b) electric starting motor
(c) direct air admission
(d) vane type air motors
(c) direct air admission
Auxiliary diesel engine electric starting motors use __________.
(a) low amperage, high voltage AC power
(b) alternating current transformers
(c) 400 cycle per second motor-generator power
(d) battery power direct current
(d) battery power direct current
Fuel injection pumps using the port and helix metering principle requires the use of a __________.
(a) crosshatched design
(b) lapped plunger and barrel
(c) variable stroke
(d) variable cam lift
(b) lapped plunger and barrel
Which of the operating characteristics listed is correct concerning the blower shown in the illustration? Illustration MO-0082
(a) Each of the lobes are in constant contact with each other
(b) Air delivery is inversely proportional to engine speed.
(c) Air delivery is approximately proportional to engine speed.
(d) The blower is driven by engine exhaust gases
(c) Air delivery is approximately proportional to engine speed.
[Supercharger, mechanically driven by crankshaft.]
The exhaust gas temperature prior to entering the turbocharger, of the system shown in the illustration, is 100°- 150° (37.8°-65.5°C) higher than the individual cylinder temperatures. This indicates __________. MO-0076
a) an exhaust valve leak
b) an exhaust manifold leak
c) the turbocharger is fouled
d) a normal condition
d) a normal condition
[Exhaust gases entering the turbocharger are normally higher than when leaving the cylinders due to a compressive effect as it enters the turbo.]
Which of the operating characteristics listed would apply to the turbocharger shown in the illustration?
a) The turbine operating speed is dependent on engine load.
b) The air is compressed in the air cleaner.
c) The compressor operating speed matches the engine operating speed.
d) Compressor power consumption varies directly as engine speed varies.
a) The turbine operating speed is dependent on engine load.
A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water __________.
(a) overboard
(b) around the cooler
(c) to the expansion tank
(d) around the engine
(b) around the cooler
The temperature at which an adjustable bellows type thermostatic valve operates is determined by __________.
(a) changing the position of the actuating bulb
(b) varying air loading pressure to the bellows
(c) replacing the bellows with a heavier spring
(d) changing the spring compression opposing the bellows
(d) changing the spring compression opposing the bellows
Which of the following conditions is NOT an indication of microbial contamination of the fuel supply? A Evidence of corrosion B Pitting of metal surfaces C Presence of green slime D Brightening of copper bearing metals
D Brightening of copper bearing metals
[Evidence of microbial contamination includes: corrosion, pitting and green slime.]
Which chemical is most often utilized to prevent and correct most microbial contamination occurring within fuel storage systems? A Potassium salts B Sodium chlorides C Biocides D Paraffin waxes
C Biocides
Diesel engine cylinder head test cocks are used to \_\_\_\_\_\_\_\_\_\_. A check cylinder lubrication B connect the pressure indicator C pressure test cylinder heads D connect the exhaust gas pyrometers
B connect the pressure indicator
A normally operating diesel engine is shutdown by __________.
(a) shutting off the air supply
(b) over speeding the engine
(c) securing the fuel supply
(d) securing the ignition system
(c) securing the fuel supply
Black smoke exhausting from an operating diesel engine is an indication of poor combustion which may be caused by __________.
(a) water in the fuel
(b) insufficient fuel for combustion
(c) clogged air intake passages
(d) burning lubricating oil
(c) clogged air intake passages
A dry-type exhaust silencer clogged with soot, will cause __________.
(a) low exhaust temperature
(b) loss of engine power
(c) burned intake valves
(d) engine racing
(b) loss of engine power
Which of the following precautions should be taken prior to starting the separator shown in the illustration? MO-0127
(a) Make sure the separator is properly assembled.
(b) Check for the correct oil level in the gear housing.
(c) Release the bowl brake and confirm proper valve line up.
(d) All of the above are correct.
(d) All of the above are correct.
The auxiliary boiler feed water level control shown in the illustration, utilizes __________ . MO-0047
A two position differential gap action
B proportional action
C proportional plus reset action
D proportional plus reset plus rate action
A two position differential gap action
The purpose of an interference angle in a diesel engine exhaust valve is to \_\_\_\_\_\_\_\_\_\_ . I. seat the valve quickly II. break up seat deposits A I only B II only C both I and II D neither I nor II
C both I and II
The purpose of an interference angle in a diesel engine exhaust valve is to \_\_\_\_\_\_\_\_\_\_ . I. break up seat deposits II. work in conjunction with valve rotators to rotate the valve A I only B II only C both I and II D neither I nor II
A I only
The piston rod scraper box incorporated in a two-stroke/cycle, crosshead diesel engine serves to __________.
(a) eliminate the necessity for an oil scraper ring
(b) prevent side thrust and cylinder scoring
(c) prevent sludge and dirty oil from entering the crankcase
(d) scrape oil and carbon deposits off the cylinder walls
(c) prevent sludge and dirty oil from entering the crankcase
What is the best way of stopping an over speeding diesel engine?
(a) Disconnect the battery cables from the starting motor.
(b) Drain the hydraulic fluid from the governor sump.
(c) Block the flow of cooling air to the radiator.
(d) Secure the fuel supply and block the air intake
(d) Secure the fuel supply and block the air intake
The device shown in the illustration is a \_\_\_\_\_\_\_\_\_\_ . A three-way spring valve B hydraulic lash adjuster C multi-directional relief valve D valve stem spring cap
B hydraulic lash adjuster
In diesel engines, hydraulic valve lifters are used to __________.
(a) obtain greater valve lift
(b) create longer valve duration
(c) reduce valve gear pounding
(d) increase valve operating lash
(c) reduce valve gear pounding
The function of device “O” shown in the illustration is to __________. MO-0110
(a) provide a positive suction head for the brine pump
(b) regulate the amount of brine entering the unit
(c) control the amount of brine exiting the evaporator
(d) control the amount of feed water entering the evaporator
(d) control the amount of feed water entering the evaporator
What occurs in the space labeled “G” of the device shown in the illustration? MO- 0110
(a) Jacket water is heated in the boiling chamber.
(b) The feed water enters the device and vaporizes under vacuum conditions.
(c) The feed water is cooled prior to being pumped into section “F”.
(d) Scale accumulates at position “E”.
(b) The feed water enters the device and vaporizes under vacuum conditions.
Which of the following conditions occurs in the section labeled “F” of the device shown in the illustration? MO-0110
(a) Non-condensable vapors are removed and water vapors are preheated.
(b) The sea water flowing through device “I” is cooled.
(c) The jacket water flowing through device “I” is heated.
(d) The vapors produced in section “G” are condensed and the non-condensable gases are
removed.
(d) The vapors produced in section “G” are condensed and the non-condensable gases are
removed.
What is the function of device “B” shown in the illustration? MO-0110
(a) It serves to boil off incoming feed water.
(b) It condenses the vapors formed in section “G”.
(c) It removes sensible heat from the jacket water.
(d) It serves to cool incoming feed water.
(b) It condenses the vapors formed in section “G”.
What is the function of device ‘C’ shown in the illustration? MO-0110
(a) The division plate creates a pressure drop between the two stages.
(b) It allows for access into section ‘F’.
(c) It controls the amount of vapor produced in section ‘F’.
(d) It removes moisture entrained in the vapors produced in section ‘G’.
(d) It removes moisture entrained in the vapors produced in section ‘G’.
What is the function of item ‘D’ shown in the illustration? MO-0110
(a) It condenses the distillate.
(b) It heats the entering feed water.
(c) It causes the jacket water to evaporate.
(d) It heats the jacket water entering the device.
(b) It heats the entering feed water.
