Stationary engines Flashcards
when entering a large engine you would _____________to ensure safe entry
lock the flywheel
block the crankshaft throws
block the engine
the 1st and 2nd answers are correct
1st and 2nd answers are correct
when working on a large stationary engine, you should always
disconnect the power source
blind the piping valves
purge engine cylinders
all the above
All of the above
when claculating torque, distance is the
diameter at which the force acts
circumference at which the force acts
radius at which the force acts
all the above
Radius at which the force acts
power is the
applied force causing movement of an object
action of one body on another
resistance of motion between 2 objects
the rate at which work is done
Rate at which work is done
brake horse power is the
theoretical power of the engine
power to overcome engine friction
actual power measured at the end of the crankshaft
BHP = IHP + FHP
Actual power measured at the end of the crankshaft
stroke can be
the movement of the piston from TDC to BDC
the diameter of the bore
the same as the bore diameter on a square engine
both the 1st and 3rd answers are correct
Both 1st and 3rd are correct
clearance volume is the
the distance from the top of the cylinder to top dead center.
the volume left in the cylinder between the piston and cylinder head when the piston is at TDC.
is the volume left around the piston so the piston does not contact the cylinder wall.
all the above
the volume left in the cylinder between the piston and cylinder head when the piston is at TDC.
volumetric efficiency is
how well the engine converts energy in the fuel to the mechanical energy
the ratio of the volume of atmospheric air drawn into the cylinder on the intake stroke to the cylinder displacement
the displacement plus the clearance volume divided by clearance volume
none of the above
The Ratio of the volume of atmospheric air drawn into the cylinder on the intake stroke to the cylinder displacement
blowby is the leakage of engine oil by the piston rings and into the crankcase
true
False
False
Blowby is the leakage of gasses or pressure into the crankcase
for an engine to have combustion, it will need which of the following
fuel, air, spark
fuel, air, gas
fuel, air, compression of ignition
both the 1st and 3rd answers are correct
Both 1st and 3rd are correct
on a 4 stroke engine, the exhaust valve cracks open at the end of the ________stroke
compression
intake
power
exhaust
Power
on a 2 stroke engine, a complete cycle takes place in__________of the crank shaft rotation
720 degrees
360 degrees
180 degrees
480 degrees
360 degrees
on a 2 stroke engine, the exhaust and intake happens almost simultaniously near
BDC
TDC
BDC
.crankshaft rotation can be CW or CCW and is viewed from the ________end of the engine
harmonic balancer
crankshaft
flywheel
fan
Flywheel
the numbering of the cylinders starts at the end of the engine, furthest from the_________
harmonic balancer
crankshaft
flywheel
fan
Flywheel
the firing order is
established by the crankshaft throws and the arangement of the lobes on the camshaft
can be any random numbering of the cylinders
helps improve fuel consumption
all the above
Established by the crankshaft throws and the arrangement of the lobes on the camshaft
running mates
apply to 4 stroke engines only
apply to 2 stroke engines only
refers to the 2 cylinders that have the pistons reaching TDC at the same time
both the 1st and 3rd answers are correct
Both 1st and 3rd are correct
which of the following is not a valve arrangement on an engine
opposed
overhead
multi-valve
flat head
Opposed
overhead cams are used on smaller engines and they solve the problem of valve train mass
true
false
true
naturally aspirated engines
do not achieve 100% volumetric efficiency
use atmospheric pressure to push air into the system
are 4 stroke engines
all the above
All of the above
compression ingnition engines have__________then spark ignition systems
higher compression ratios
higher compression temperatures
a lighter weight
both the 1st and 2nd answers are correct
Both 1st and 2nd answers are correct
intergral engines
have the load attached to either end of the engine
have the load as part of the engine
Have the load as part of the engine
when the main bearing caps for the crankshaft are mounted below, it is called
under slung
over slung
multi-piece
2 piece
Under slung
if testing the block for cracks using pressure, make sure to use no more than ________psi
10
25
35
45
45
to correct issues with the bore of the main bearings, you would
shim the bearing caps
use a die grinder
line bore
none of the above
Line bore
on large engines, you can use a deflection gauge positioned between _________to find crankshaft alignment
the caps
the connecting rods
the bearings and journals
the counter-weights of crankshaft
The counter weights of the crankshaft
when doing a line bore, it is important to keep the crankshaft centerline as close to its original centerline as possible
true
False
True
the highest wear area in a cylinder is near the
bottom of the stroke
middle of the stroke
top of the stroke
same thru the entire stroke
Top of the stroke
the difference between dry and wet liners is the
wet liners inside bore is explosed to the coolant
dry liners exterior is not exposed to the coolant
wet liner is harder to take out then a dry liner
wet liners are made of thinner material then dry liners
Dry liners exterior is not exposed to the coolant
liner bore inspection is done
after the liner is taken out of the block
before the liner is taken out of the block
it does not matter
Before the liner is taken out of the block
major cylinder wear will take place at the ________ of the cylinder during the _______ stroke (thrust side)
bottom, power stroke
top, power stroke
bottom, compression stroke
Top
power stroke
when measuring a cylinder liner bore, you will take measurements in 2 places around the bore, 1 in line with the crankshaft and 1- 90 degrees to the crankshaft. you will take these 2 measurements at the top, bottom and middle of the liner length. (3 places)
true
False
True
cavitation on a wet cylinder liner will happen on the coolant side of the liner. to help this you can
pressurize the cooling system
chrome plate the outside of the liner
add additives to the coolant
all the above
All of the above
a ridge reamer is a tool used to
true the piston
true the cylinder bore its full length
take the ridge off of the top of the cylinder bore
clean the piston rings
Take the ridge off the top of the cylinder bore
when deglazing, you want your cross hatch pattern to be ___________ degrees
40-60
30-40
20-40
60-80
40-60 degrees
it is important to measure removable liner bores for
maximum diameter
out of round
taper
all of the above are correct
All of the above are correct
the wet liner counter bore should be checked for depth and flatness so the _______ of the liner will be correct
sealant seal
protrusion
bore
block deck
Protrusion
for proper sealing of the wet liner, you need to
untwist and seat all 0-rings
lubricate 0-rings
put RTV sealant under the top liner flange
all the above
All of the above
the __________ are off center to harness the piston motion of the engine
webs
main bearings
throws (conneting rod journals)
counter-weights
Throws
when inspecting the crankshaft, you should ____________ to determine if it needs repair
refer to manufactures specifications
measure crankshaft journals in 2 places, 90 degrees from each other
check for taper and proper fillet radius
all the above
All of the above
the fly wheels main job is to
balance the engine
start the engine
stabalize the speed fluctuations and store energy during power pulses
allow for pinning during shut down
Stabilize the speed fluctuations and store energy during power pulses
a harmonic balancer is used to dampen torsional vibration from the crank twisting. which is not a type of dampner
rubber mounted
viscous
spring
solid metal
Solid metal
embeddability of a journal bearing is its ability to
withstand penatration
withstand shock
absorb small particles
resist heat
Absorb small particles
.crush in manufactured into a journal bearing to achieve a secure fit in the bearing housing after being installed and torqued
true
false
True
plastigage is a method of checking for the amount of bearing clearance when the crank is installed. it will be placed between the
bearing and bearing cap
bearing and the crankshaft (crankshaft bearing surface)
bearing and the block
all the above
Bearing and the crankshaft
if you use the lift method for checking bearing clearance, you would place the dial indicator on the ___________ when checking the main bearing clearance
block and read off the connecting rod
the block and read off the crankshaft
the crankshaft and read off the block
the crankshaft and read off the connecting rod
Block and read off the crankshaft
a roll pin is used to
measure the new bearings for size
hold the plastigage durnig crush
locate the dowel pins
take out and put in bearing halves with the crankshaft in place
Take out and put in bearing halves with the crankshaft in place
avoid touching the bearing surfaces with your fingers as it may cause
corrosion
distortion
clearance loss
all the above
Corrosion
once the correct clearances are verified for the crankshaft, you will
make sure the rear main seal is lubed and in place
align thrust bearings
check crankshaft end play
all the above
All of the above
you should always match mark connecting rods and caps if they are not marked
true
false
True
the rod bolt torque method(s) could be
torque wrench
torque turn method
elongation
all the above
All of the above
pistons have rings around their circumference to
provide dynamic sealing between piston and cylinder wall
prevent combustion pressures from entering the crank
prevent oil from entering the combustion chamber
all the above
all of the above
the crosshead type piston is
one piece design
a 2 piece design
flexible becasue the crown can expand separately from the piston skirt
the 2nd and 3rd answers are correct.
Both 2nd and 3rd are correct
compression rings are activated by gas pressure from the compression and combustable gases pushing
up on the rings
down on the rings
down and out on the rings
up and out on the rings
Down and out on the rings
.when checking piston rings during installation, you should have the right amount of end gap and side clearance to help eliminate oil consumption and blowby
true
False
True
when installing piston rings with an internal chamfer, the chamfer should face down
true
False
False
Should face up
you will need to rotate the crankshaft to TDC to help install the piston and rod
true
False
False
when you torque the bolts on an engine, make sure to follow manufacturers specifications
true
False
True
the camshaft has lobes that help determine the
lift of the valve
length of time the valve stays open
valve overlap
all the above
All of the above
the cam shaft on a 4 stroke engine turns________of the crankshaft
the same speed
2 times the speed
1/2 the speed
none of the above
1/2 the speed
lifters and pushrods transfer motin from the ______to the________ in camshaft in block engines
crank, valves
cam, valves
valves, rocker arm
cam, rocker arm
Cam, rocker arm
____________ lifters do not need to be adjusted after the initial adjustments
hydraulic
solid
Hydraulic
the valve bridge or cross heads are used for on cylinder heads with 4 valves per cylinder
true
false
True
valve seat width is important because
if it is to wide, there could be carbon build up
if it is to narrow, there could be excess cooling
both the 1st and 2nd answers are correct
none of the above
Both first and second answers are correct
if valve guides and seats are worn, then the __________ should be done forst
valve guides
valve seats
Valve guides
valve clearnace is set up between the rocker arm and the pushrod to compensate for component expansion and wear of the valve operating mechanism
true
False
False
Between the rocker arm and valve
valve clearance is set when the valve is open
true
False
False
when valve is closed
the back pressure in an exhaust system should be_________
1 psi
4 psi
8 psi
10 psi
1 PSI
a catalytic converter is working properly when the temperature is_________
100 degrees F higher at the inlet then the outlet
38 degrees F higher at the outlet then the inlet
100 degrees F higher at the outlet then the inlet
38 degrees F higher at the inlet then the outlet
100 degrees F higher at the outlet then at the inlet
for most engines, the ideal cooling temperature for the engine to run properly is between _______ degrees F
180 to 200
300 to 350
32 to 200
none of the above
180 to 200 degrees F
82 to 95 C
the thermostat must be installed so the temperature sensor faces toward the engine
true
false
True
coolant is usually a mxture of _______ water to ______ antifreeze
20, 80
80, 20
70, 30
50, 50
50 50
system operating pressure in a lubrication system is determined by the
oil stop valve
oil sump
bearing clearances
maximum pressure relief valve
Bearing Clearances
filters in a lubrication system can be full flow filtration or bypass filtration
true
False
True
depth type filters trap particles below the surface with the use of cotton, wood chips and steel wool
true
False
True
pumps that supply oil to the bearings before start-up or during cool down are called post lube or pre-lube pumps
true
False
True
oil changes can be influenced by
fuel type
environmental conditions
volume of oil in the sump
all the above
All of the above
when changing oil, you should make sure to _______on large stationary engines
change the oil while it is still warm and just after it is shut down
change the oil when it has cooled down
change the oil every 5000 hrs
does not matter when you change the oil
Change the oil while it is still warm and just after it has shut down
if you have a problem with low oil pressure, it might be
higher than normal bearing clearances
new bearings that are to tight
relief valve may be stuck closed
all the above
Higher than normal bearing clearances
crankcase ventilation systems are designed to remove __________ from the crankcase
intake gases
head gases
blowby gases
gas tank gases
Blowby gases
a fuel with a high octane rating will
burn fast
burn slow
Burn slow
pre-ignition is caused by
extreme compression of the gas after initial ignition
hot spots in the cylinder
to long of a spark plug
to short of a spark plug
Hot spots in the cylinder
carburetors operate on a venturi action. this is similar to
pascal’s law
bernoulli’s principle
the law of conservation
Bernoulli’s principle
some fuel injection systems spray the gas into the _______ with ______
carb, fuel pressure
intake system, fuel pressure
cylinder, vacuum
head, atmospheric pressure
Intake systems with fuel pressure
the oxygen sensors in an electronic fuel injection system sense the _________ at the _________
oxygen levels, intake
CO2 levels, sparkplug
CO2 levels, carb
oxygen levels, exhaust
Oxygen levels at the exhaust
a fuel-gas scrubber is used in natural gas systems to clean the gas
true
false
tRUE
with natural gas and propane sustems, it is important to have a ____________ in the system for safety during stalls
pressure regulator
gas filtering system
automatic shut-off valve
expansion tank
Automatic shut off valve
LPG is 1 1/2 times heavier than air, has a boiling point of -42 degrees C and expands _____________ when it vaporizes
50 times its volume
100 times its volume
200 times its volume
270 times its volume
270 times its volume
to reduce the higher pressure liquid propane to a low pressure vapor, the gas passes thru the
filter
spray bar
converter/regulator
Converter/regulator
in diesel fuel systems, the ignition stage takes place because of the
heat of exhaust
heat of compression
low pressures
none of the above
heat of compression
to help start a diesel engine, you can use glow plugs and /or a higher cranking speed of the engine so more heat is available to help ignite the fuel
true
False
True
inline fuel injection has its own cam and plunger for each cylinder
true
False
True
the most efficient filtering system for an induction system on engines is the
spiral rotor (turbo)
Dry
oil bath
manometer
Dry
turbo lag is a result of
play in linkages
driving the turbo with the engine
driving the turbo with the exhaust
all of the above
Driving the turbo with the exhaust
the stationary diffuser in a turbo charger converts the kinetic energy of the moving air into increased pressure
true
False
True
to control the amount of boost (pressure) from a turbocharger, you would sense the output pressure of the compressor and the pressure would operate a waste gate by means of an actuator rod
true
False
True
spark plugs can be a hot plug or a cold plug. cold plugs are good for engines running at full load and hot plugs are used for engines running at low load or idling. (the length of the heat path determines if it is a hot or cold plug)
true
False
True
.the magnetic pulse generator is a common triggering device in electronic distributors
true
False
True
1 cylinder lead
ignition timing is done by using a timing light hooked up to the
2 cylinder lead
it does not matter which one it is hooked uo to
1 Cylinder lead
air starting of large engines can be used with reduced gearing or the air directed into the cylinders themselves
true
False
True
to reduce the likely hood of installtion problems with a stationary engine,, the foundation should have a mass of
1.5 times the engine
2.5 times the engine
3.5 times the engine
4.5 times the engine
2.5 times the engine
.skid mounting of an engine is ideal for smaller engines
true
False
True
some engine installations use vibration isolators to keep the vibration away from other machinery
true
False
True
when using a block mounted installation for an engine, the best type of anchor bolt would be
j-bolts
piped
boxed
expansion
Boxed
the sole plate is the load bearing steel plate that is ______ to the foundation
not level
anchored and grouted
perpendicular
none of the above
Anchored and grouted
shims are used between the_____ and the______ to make fine adjustments
foundation, engine base
engine base, sole plate
engine, grout
none of the above
Engine base and sole plate
epoxy grouts are used becasue they are
strong
easy to use
don’t shrink
all the above
All of the above
exhaust piping for stationary engines should have ________ to help with vibration isolation and thermal expansion
rigid piping
flexible piping or expansion joints
plastic piping
loosened mounting brackets
Flexible piping or expansion joints
ventilation of an engine building should have the inlet source for the air higher then the outlet
true
False
False
Inlet source should be below the outlet air
when shutting down a large natural gas stationary engine, never shut off the fuel valve to stop the engine
true
false
False
shut off the fuel valve
when starting a large engine, you should start the pre-lube pump before you do an engine cranking
true
False
True
an electronic control system for a large stationary engine is used to monitor and control the engine. it is also used to shut down the engine in the event of a critical alarm
true
False
True
basic pressure devices that should be monitored on a stationary engine, are lube oil, jacket water, air manifold and crankcase pressure
true
False
True
the 2 areas of engine troubleshooting are, to determine if the engine has the basic requirements to operate and does it’s mechanical state need correction
true
false
True
on ignition systems, new magnetos must be timed when installed. this is done by rotating the flywheel until the proper timing mark aligns with the timing hole pointer in the flywheel housing and the engine is on # 2 cylinder TDC firing. (for most engines)
true
False
False
#1 cylinder TDC
you will test for compression in an engine when the sparkplugs are in the engine
true
False
False
Spark plug tester goes in the spark plug hole
.valve clearance adjustments can be made on solid lifters. the least confusing way to do this is to start at # 1 cylinder at TDC at the end of the compression stroke and then proceed in the firing order
true
False
True
electric motors are
DC
AC polyphase
AC single phase
all the above
All of the above
the power rating of an electric motor refers to the value of output power that a motor will produce at the shaft
without overheating
regardless of a temperature rise
at 125% efficiency
all the above
Without over heating
for every 18 degrees F rise in insulation temperature above the rated values, the life of the motor is reduced by ________%
10
25
50
75
50%
.the NEMA motor enclosure type which can prevent ignition of gases or vapors surrounding the machine is the
water proof
totally enclosed fan cooled
explosion proof
weather protected type 2
Explosion proof
the speed control of DC motors is
uncontrollable
unreliable
inaccurate
percise
Precise
the part of the DC motor that is made from carbon steel and acts as a stationary support and also the return path for the magnetic flux that passes from the field poles to the armature is the
armature
armature windings
main frame
commutator
Main frame
the component on a DC motor which are used to make a low resistance contact with the commutatot is the
carbon brushes
armature
main frame
field poles
Carbon brushes
a DC motor may be slowed down or brought to a quick stop by
dynamic braking
regenerative braking
plugging
all the above
All of the above
squirrel cage induction motors
have no physical connection between the stator and the rotor
have a commutator and carbon brushes
require rheostaatic speed control
all the above
Have no physical connections between the stator and the rotor
three phase motors are the most common type in industry because they are
of simple design and reliable
rugged and low maintenance
efficient and low cost
all the above
All of the above
the formula for synchronous speed is
60 X frequency/ #of poles
60 x frequency x # of poles
120 x frequency / # of poles
120 x frequency x # of poles
120 x frequency / # of poles
the synchronous speed in synchronous motors means that there is
no difference in the speed of the rotor and the speed of the rotating magnetic stator field
a lag in the speed of the rotor in relation to the stator field
an advance speed of the rotor in relation to the stator field
none of the above
no difference in the speed of the rotor and the speed of the rotating magnetic stator field
an electric motr failure is associated with
mechanical problems
lack of maintenance and general deterioration
the quality of electrical power supply
all the above
All of the above
one of the principle and common causes of electic motor bearing failure is
improper installation
over lubrication
looseness
misalignment of bearings in the housing
Over lubrication
extremely high current flow rates upon start-up over heat motors. large motors are ussually limited to ___ starts per hour
2
6
10
15
2
