In comparison to exhaust
valves, intake valves of diesel engines may be fabricated from low-alloy steels
because _____________./intake valves are
less affected to the corrosive action of exhaust gases
The opening of an exhaust
valve on a modern, large, low- speed, main propulsion diesel engine, may be
actuated by _____________./hydraulic "push rods"
The closing of the
exhaust valves used on a modern, large, low-speed, main propulsion diesel
engine may be directly provided by _____________./compressed air pressure
If the intake, or exhaust
valve stem clearance is found to be excessive, in addition to too little
movement of the rocker arms, you should
check for _____________./collapsed hydraulic valve lifters
A burned exhaust valve
may be detected by a higher than normal
____________./exhaust temperature from a particular cylinder
Which of the listed
conditions will occur if a diesel engine exhaust valve is leaking?/All of the
above
In a diesel engine, a
leaking exhaust valve can cause
_____________./misfiring
Exhaust valve grooving
and corrosion is caused by certain components of residual fuel oil. These
components are sodium, sulfur, and
_____________./vanadium
The easiest way to locate
a defective diesel engine exhaust valves is by _____________./comparing exhaust
pyrometer readings
Increasing the exhaust
valve tappet clearance of a diesel engine will result in the exhaust valve
opening __________./later and closing earlier
Diesel engine exhaust
valve springs are under compression when they are __________./in any position
A diesel engine exhaust
valve spring is under compression when _____________./all of the above
The intake and exhaust
valves used in a diesel engine are returned to their seats by
_____________./spring force
In which of the
scavenging methods listed will the exhaust valve be located in the cylinder
head?/Uniflow
The purpose of an
interference angle in a diesel engine exhaust valve is to ________. I. work in conjunction with valve rotators to
rotate the valve II. break up seat deposits/II only
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/I only
The
exhaust valve opens
before bottom dead center in a four stroke engine to___________. I.
allow for blow down II. reduce pumping losses/both I and II
The
purpose of an
interference angle in a diesel engine exhaust valve is to ________. I.
seat the valve quickly II. break up seat deposits/both I and II
The purpose of an
interference angle in a diesel engine exhaust valve is to ________. I. work in conjunction with valve rotators to
rotate the valve II. seat the valve quickly/II only
In
a diesel engine,
exhaust valves open before the intake ports are uncovered to
___________. I. reduce pumping losses II. reduce back pressure/both I
and II
A substance found in
residual fuels which tends to cause exhaust valve corrosion and grooving, is
____________./vanadium
During diesel engine
warm-up, which type of valve lash
adjuster listed allows for the change in length of the exhaust valves?/Hydraulic
Which of the listed
design features is found in an exhaust valve and NOT in an intake valve?/Hard
alloy steel construction
Many diesel engine
exhaust valves are being constructed with hollow stems filled with sodium in
order to _____________./assist in dissipating heat due to the extreme
operating temperatures
A built-up exhaust valve
is one in which _____________./the stem and heads are made of different
material
The size of the exhaust
valve opening is ____________./most critical in a two-stroke/cycle diesel
engine
Exhaust valve openings in
a diesel engine cylinder head are made as large as practical to
_____________./reduce the pumping loss associated with scavenging
The satisfactory
operation of diesel engine exhaust valves usually depends on
______________./correct timing and proper seating
Decreasing the exhaust
valve clearance of a diesel engine will cause the exhaust valve to open
______________./earlier and remain open longer
Multiple concentric valve
springs are often used with diesel engine valves to ____________./operate the
valve gear where a larger force is normally
required, but space limitations restrict the use of a single large
spring
If the valve tappets in a
diesel engine are set at greater clearances than those specified by the engine
manufacturer, those valves will _____________./open late and close early
Increasing the valve
clearance between a valve stem and
rocker arm, will result in the valve _____________./staying open for a
shorter period of time
Which of the listed items
should be secured before performing any
maintenance on a solenoid operated air start valve?/Electric power
An important design
characteristic of an explosion relief valve for a diesel engine is the ability
to _________./close quickly in order to prevent an inrush of air
Which statement regarding
the arrangement and location of explosion relief valves used on an internal
combustion engines is
true_____________?/Minimizing the danger from emission of flame is a key consideration
Collapsed hydraulic valve
lifters in a diesel engine will result in ____________./excessive valve
clearance
At what pressure should a
cylinder relief valve of an internal
combustion engine be set to relieve?/The device should be set to relieve at a
pressure not more than 40 percent in excess of the maximum firing pressure.
The diesel engine valve
subjected to most severe conditions of service is the ____________./cylinder
exhaust valve
When the cold tappet
clearance is less than that specified by the engine manufacturer, the diesel
engine valves will _____________./open earlier than normal
In diesel engines,
hydraulic valve lifters are used to
____________./reduce valve gear pounding
Valve lash, or clearance
refers to the _____________./clearance between the top of the valve stem and
the rocker arm
What is the purpose of a
hydraulic valve lash adjuster?/Allows for constant contact between the valve
stem and the rocker arm regardless of whether the engine is cold or warm.
Diesel engine valve
springs function to _____________./close the valves
Valve cages are used on
some large diesel engines to _____________./facilitate
valve removal for servicing
During warm-up the
expansion of valve stems due to engine heat, is allowed for by the
_____________./valve lash
In a diesel engine, the
spring force required for proper valve operation is determined by _____________./cam
contour
According to Coast Guard
regulations, isolation valves used in keel cooler installations are permitted
to be constructed of ____________./bronze
If a single cylinder
relief valve on a diesel engine lifts frequently while the engine is running,
the cause may be an _____________./incorrectly adjusted fuel injector
Diesel engine air start
valve timing is controlled by
_____________./individual cams and valve gear
If there is a
"clicking" sound in the valve compartment of a diesel engine, the
cause may be _____________./excessive valve lash
Excessively worn, or
polished ends on a diesel engine valve spring, indicate
________________./spring surge
Excessive valve clearance
will cause a valve to open
_____________./late and close early
The valve stem expansion
associated with engine warm-up is allowed for by the ____________./valve lash
adjusters
Diesel engine air start
system check valves are opened by _____________./starting air pressure
Excessive valve lash in
an auxiliary diesel engine will cause
the valves to open _____________./later and close sooner
If the valve lash on a
diesel engine is set improperly, which
of the following statements represents the most
serious problem that can develop?/Too little lash may prevent the valves
from seating properly.
If you increase the
clearance between a valve stem and
rocker arm, which of the listed conditions will occur?/Valve will open
later.
Reducing the clearance
between a valve stem and rocker arm will result in the valve _____________./having
a longer duration of opening
If you were inspecting
the valve springs on an auxiliary diesel engine, your best indication of
impending spring failure would be
_____________./cracks in the surface of the spring
If the relief valve on a
diesel engine cylinder lifts, the cause could be due to _____________./liquid
in the cylinder
Which of the listed items
should be secured before performing any
maintenance on a solenoid operated air start valve?/Electric power and starting
air
Bouncing of the valve gear
in a diesel engine can be caused by _____________./spring surge
Spring surge in diesel
engine valve springs can result in _____________./bouncing of the valve gear
If a clicking sound is
being produced from within the valve compartment of a diesel engine, the cause
may be __________./all of the above
The force exerted by a
valve spring to close the diesel engine
valves, is proportional to _____________./spring compression
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1 comments:
It is very good post containing Exhaust and inlet valves question.
exhaust valves
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