WorksheetsMotor 1
Total questions: 50
Worksheet time: 25mins
Friction developing between the moving parts of a governor, governor linkage and control valve will cause the governor to __________.
react with insufficient speed droop
fail to react to small speed changes
have excessive sensitivity to small speed changes
remain in the neutral position
Diesel engine jacket water is used in the fresh water distillation process as the __________.
coolant for the distillate
coolant for the brine cooler
means of heating the feedwater
primary means of producing a vacuum within the distiller
Microbiological growths in marine fuel are a common occurrence that can be __________.
extremely detrimental to equipment and operating processes
prevented by maintaining higher storage temperatures
removed from emulsified fuel oil during the centrifuging processes
All of the above are correct.
When a waste heat boiler is installed in the exhaust of a main propulsion diesel engine, the exhaust gas bypass would be used __________.
at high loads to prevent overheating
at low loads to prevent corrosion in the boiler
during periods of high steam demand
when the turbocharger is in operation
Which of the following statements describes the function of an expansion tank in a diesel engine cooling system?
Maintains a constant head on the system.
Reduces the likelihood of air or steam pockets formation.
Provides a low pressure point for the addition of makeup cooling water and chemicals.
All of the above.
Throttling a burner air register on an auxiliary boiler could result in __________.
smoky boiler operation
decreased fuel consumption
improved fuel combustion
fewer soot deposits
Lubrication for the main reduction gears used with diesel engines is usually supplied by __________.
oil from the main engine sump
an independent lube oil system
the stern bearing head tank
the stern bearing sump tank
The most common cause of scale formation in an auxiliary boiler is __________.
concentrations of calcium sulfate in the boiler water
fuel oil in the feedwater
improper treatment of the feedwater with calcium sulfate
excessive feedwater alkalinity
The concentration of dissolved solids in the boiler water of an auxiliary boiler could increase as a result of __________.
phosphate treatment
zero water hardness
dissolved oxygen deaeration
frequent bottom blows
With regards to a diesel engine crankcase explosion, the most violent is the __________.
I. primary explosion
II. secondary explosion
I only
II only
both I and II
neither I or II
In which of the following areas of a crosshead engine is a permanently connected fire extinguishing system required?
Exhaust manifolds in excess of eight inches in diameter.
Crankcases having a gross volume in excess of 21 cubic feet.
Turbocharger inlet piping in excess of twelve inches in diameter.
Scavenging spaces in open connection to the cylinders.
What could cause the bypass valve in a full-flow lubrication system to open?
Clogged filter element
Bypass valve setting is too high
Check valve stuck open
Fuel dilution of the lubricant
Auxiliary boilers can be classified as __________.
water-tube natural circulation boilers
fire-tube boilers
water-tube forced circulation boilers
all of the above
Valves used in diesel engine fuel oil pressure piping are to be __________.
so constructed as to permit packing under pressure
solenoid released upon the failure of engine lubrication
either of the gate or globe valve type
forge constructed under the approval of the Marine Inspector
Which of the following statements best describes the operational characteristics of an isochronous governors?
They are suitable for use on main propulsion units.
They strive to maintain a constant prime mover speed for all values of steady load.
They cause a proportional drop in prime mover speed as the load is increased.
They have poor sensitivity at high RPM.
A seven cylinder, two-stroke/cycle, single acting diesel engine with a cylinder indicated horsepower calculated as 1350 kW and brake horsepower measured at 7466 kW has a mechanical efficiency of __________.
18%
55%
79%
83%
During the operation of the fuel oil centrifuge shown in the illustration, it is found that the 'clean' oil discharge contains water. The most probable cause is the __________.
gravity disk is too large
throughput is too high
separating temperature is currently 95°C (203°F)
clean oil outlet valve has not been fully opened
The water inlet manifold for the diesel engine shown in the illustration is represented by the letter or number __________.
"M"
"N"
"W"
"13"
According to the chart shown in the illustration, which of the following statements is true concerning antifreeze solutions for diesel engine cooling systems?
A 100% ethylene glycol solution gives the greatest protection against freezing.
The boiling temperature of the solution remains constant at the level of greatest protection against freezing to -70°F (-57°C).
With antifreeze protection of -60°F (-51°C), the boiling temperature could be 230°F to 250°F (110°C to 121°C).
A 30% solution of ethylene glycol will protect the cooling system at temperatures of -18°F (-26°C).
A six cylinder 2-stroke/cycle, single acting diesel engine has a 580 mm bore and a 1700 mm stroke. What indicated power per cylinder will be developed if the average mean effective pressure is 15.3 kg/cm2 at a speed of 120 RPM?
1,366 kW
2,696 kW
4,044 kW
8,088 kW
As illustrated, what is the maximum allowable clearance permitted between the bearing and the shaft along its vertical axis?
1.00 mm
0.30 mm
0.46 mm
0.80 mm
Late fuel injection in a diesel engine is indicated by low firing pressure with __________.
high exhaust temperature
low exhaust temperature
fuel knock in each cylinder
mechanical knock in each cylinder
Which of the indicator diagrams illustrated depicts the condition that should be corrected by retarding only the timing?
A
B
C
D
The term 'diesel engine cylinder scavenging' means __________.
delivering more air into the cylinder than it would normally receive during an ordinary charging process
forcing the products of combustion out of the cylinder with the fresh air charge
collecting the air charge at the air cleaner
combustion and expansion of hot gas
A diesel engine is supercharged in order to __________.
lower the no-load RPMs
provide more air for combining with the fuel
increase the no-load RPMs
provide more fuel for combining with the air
The RPM of "A" is 100 and has 88 teeth. If gears "B", "C", and "D" have 66, 22, and 48 teeth respectively, the RPM of "D" in the gear train illustration is __________.
61.11 RPM
412.50 RPM
550.00 RPM
45.83 RPM
The illustrated device is used to __________.supply cylinder lubricating oil to the engine
supply cylinder lubricating oil to the engine
meter fuel oil to the injectors
admit the correct amount of starting air to the cylinders in proper order
actuate exhaust valves in the correct sequence
The illustrated cylinder lubricator quill check valve can be inspected without draining the cylinder cooling water jacket by __________.
unbolting and removing the cover, item #14
unscrewing and removing item #6 from the cylinder
unscrewing and removing item #4
inspection can not be done without first draining the jacket cooling water
In the large slow-speed main propulsion diesel engine shown in the illustration, the part labeled "G" is the __________.
lube oil pump
fuel oil pump
jacket water pump
crankcase exhaust fan
Using a diesel engine indicator P-V diagram, the cylinder mean effective pressure is calculated to be 21.3 kg/cm2. What is the scale of the spring used on the indicator if the diagram area is 18.46 cm2 with a length of 13 cm?
1.5 kg/mm
5.0 kg/mm
10 kg/mm
15.0 kg/mm
You are standing watch in the engine room on your vessel. The usual symptoms of cavitation in a centrifugal pump are __________.
noise and vibration
an increase in discharge pressure
an increase in suction pressure
lifting of the relief valve
The highest indicated lube oil pressure in a diesel engine should be expected when the __________.
engine is running at its highest allowable temperature
engine is running at its normal operating speed and lowest operating temperature
load on the engine is at its rated maximum
diesel fuel dilution of the lube oil exceeds 5%
A fuel injection valve opening at a pressure lower than normal will result in __________.
late fuel injection
early fuel injection
high exhaust temperature from that cylinder
decreased effective stroke from that injector
During the compression stroke in a four-stroke/cycle, internal combustion engine, assume that the piston can only travel seven-eighths of the total distance between BDC to the underside of the cylinder head. Which of the following ratios will be the compression ratio for this engine?
6 to 1
7 to 1
7.5 to 1
8 to 1
At the end of a normal sludge ejection cycle, the bowl of the centrifuge, shown in the illustration, will be closed only when the valve(s) __________.
'V5' is closed, with 'V10,' 'V15,' and 'V16' are open
'V5,' 'V10,' 'V15,' and 'V16' are closed
'V10' and 'V16' are open, with 'V15' closed
'V5,' 'V10,' 'V15,' and 'V16' are open
Telescopic pipes which are attached to water cooled pistons of large slow-speed main propulsion diesel engines are designed to __________.
overcome excessive crankcase pressure
prevent excessive lube oil temperature
allow piston cooling water to efficiently enter the piston despite its reciprocating piston motion without contaminating the engine lube oil
prevent contamination of the cylinder cooling water with engine lube oil
What is the crank angle between cylinder firing of a four-stroke/cycle, in line, eight cylinder diesel engine?
45°
60°
90°
120°
Which precaution must be taken when securing a diesel engine if an electric jacket water heater is installed in the engine block?
The coolant temperature must always be maintained at 180°F.
The thermostatic bypass valves must be manually opened before the engine is started.
The pressure cap must be removed while the engine is secured.
Electrical power to the heater must be secured if the cooling system is to be drained.
Diesel engine injection lag is caused by __________.
compressibility of the fuel
high fuel oil temperature
low injector popping pressure
excessive air turbulence
According to the illustration, fuel injection timing into the cylinder is controlled with the component that is identified as the letter __________.
C
H
K
I
To minimize corrosion in a metal-edge strainer used in a fuel oil system, strainer disks, spacers and scraper blades are commonly made of __________.
brass
copper
iron
monel metal or stainless steel
The diesel engine component labeled "5", shown in the illustration is known as the __________.
piston crown
connecting rod end assembly
heat sink space
piston thrust washer
Which statement regarding the arrangement and location of explosion relief valves used on an internal combustion engines is true?
They may be omitted on all engines having a cylinder bore of nine inches or less
They may be omitted provided the engine utilizes a crankcase monitoring system
The type of engine and operating cycle must be considered by the designer
Minimizing the danger from emission of flame is a key consideration
The diesel engine water inlet jumper illustrated is represented by the letter or number __________.
"M"
"N"
"W"
"14"
The maximum allowable working pressure on a packaged auxiliary boiler is 200 psig. The normal working pressure for one particular packaged boiler is 175 psig. Which of the following safety relief valve settings would be proper for this boiler?
165 psig
195 psig
210 psig
220 psig
Effective hydraulic coupling operation depends upon a certain amount of __________.
slip
mechanical friction
fluid overheating
torsional vibration
When two cams of the same diameter, one with tangential flanks and the other with convex flanks are compared, the cam with tangential flanks will cause ___________.
greater valve lift
more abrupt valve action
less valve seat wear
less valve gear wear
An acceptable means of tightening connecting rod and main bearing cap bolts is to measure the __________.
I. torque applied to each nut and bolt assembly
II. stretch of each bolt after tighteningI only
II only
both I and II
neither I nor II
An eight cylinder, four stroke/cycle, single acting diesel engine has a 650 mm bore and a 1400 mm stroke. What will be the indicated power developed if the average mean effective pressure is 30 kg/cm2 at a speed of 100 RPM?
1689 kW
9,111 kW
12,388 kW
24,776 kW
A mixture of 45% cetane and 55% alpha-methyl-naphthalene is found to have the same ignition delay as a sample of diesel oil. The sample can be described as having a/an __________.
cetane number of 55
cetane number of 45
octane number of 55
octane number of 45
