Valves/Valve Gear
A built-up exhaust valve is one in which ______. a) the stem and head is made of different materials
a
Exhaust valve grooving and corrosion is caused by certain components of residual fuel oil. These components are sodium, sulfur, and ______. a) vanadium
a
Exhaust valve timing for the engine, shown in the illustration, is to be set at 106° after top dead center. To what position should the flywheel be rotated to set the exhaust valve timing on the #11 cylinder? See illustration MO-0039. a) 61°
a
If a valve seat insert, similar to the that shown in the illustration is cracked, this may be indicated by ______. See illustration MO-0043. a) white vapor in the exhaust gas
a
In a diesel engine, a leaking exhaust valve can cause ______. a) misfiring
a
In a four-stroke/cycle diesel engine, the intake valves open ______. a) before TDC and close after BDC
a
On a four-cycle diesel engine, the valve subjected to the most severe conditions during normal service is the ______. a) cylinder exhaust valve
a
The burning of fuel oil in a diesel engine having a high sodium content, will cause ______. a) corrosion and grooving of exhaust valves
a
The force exerted by a valve spring to close the diesel engine valves, is proportional to ______. a) spring compression
a
The parts labeled 'I' and 'II', shown in the illustration are respectively identified as the ______. See illustration MO-0020. a) exhaust valve and intake valve
a
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
a
The use of push rods becomes necessary in a diesel engine when ______. a) the camshaft is located some distance below the valve gear
a
The valve bridge, illustrated, allows for ______. See illustration MO-0019. a) two exhaust valves to be operated from one rocker arm
a
Turbocharged four-stroke/cycle diesel engines utilize valve overlap for ______. a) improving cylinder scavenging
a
Which letter represents the top deck (valve) cover of the engine shown in the illustration? See illustration MO-0122. a) "A"
a
Which of the following problems represents one possible cause of high lube oil consumption in a four stroke diesel engine? a) Worn intake valve guides
a
Which of the following statements describes the operational characteristics of figure "B" in the illustration? See illustration MO-0045. a) The valve will lift abruptly.
a
Which of the following statements describes the operational characteristics of figure "B" shown in the illustration? See illustration MO-0045. a) The valve will lift abruptly, and reseat gradually.
a
Which of the following statements identifies the purpose of the valve bridge shown in the illustration? See illustration MO-0019. a) Operate two exhaust valves from one rocker arm.
a
Which of the following statements is true concerning the diesel engine cylinder head and valve mechanism shown in the illustration? See illustration MO-0013. a) The rocker arm causes a valve bridge to open the valves simultaneously.
a
Which of the listed design features is found in an exhaust valve and NOT in an intake valve? a) Hard alloy steel construction
a
Worn cylinder head valve seats in a diesel engine will cause ______. a) less cold valve lash
a
A burned exhaust valve may be detected by a higher than normal ______. b) exhaust temperature from a particular cylinder
b
Bouncing of the valve gear in a diesel engine can be caused by ______. b) spring surge
b
Broken intake valve springs on one cylinder of a diesel engine can cause the engine to ______. b) fire improperly
b
During the process of cylinder scavenging, the size of the exhaust valve opening is ______. b) most critical in a two-stroke/cycle diesel engine
b
Excessive lubricating oil consumption in a running diesel engine can be caused by ______. b) excessive valve-guide clearance
b
Excessive wear at part #11, shown in the illustration would result in ______. See illustration MO-0027. b) increased oil consumption
b
Multiple concentric valve springs are often used with diesel engine valves to ______. b) operate the valve gear where a larger force is normally required, but space limitations restrict the use of a single large spring
b
Spring surge in diesel engine valve springs can result in ______. b) bouncing of the valve gear
b
The closing of the exhaust valves used on a modern, large, low-speed, main propulsion diesel engine may be directly provided by ______. b) compressed air pressure
b
The device labeled "B" in the illustration is a ______. See illustration MO-0122. b) camshaft rotating at the speed of the crankshaft
b
The device shown in the illustration is closed by force as provided by ______. See illustration MO-0066. b) "F"
b
The device shown in the illustration may be closed by using pressurized air on some recently built large low speed engines and would replace the component identified as ______. See illustration MO-0066. b) "F"
b
The intake and exhaust valves used in a diesel engine are returned to their seats by ______. b) spring force
b
The line identified as "I" in the illustration is used to ______. See illustration MO-0066. b) supply lubricating oil for actuating the exhaust valve
b
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 b) II only
b
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 b) II only
b
The valve spring shown in the illustration, functions to ______. See illustration MO-0073. b) hold the valve against its seat
b
When the #1 piston, shown in the illustration, is at top dead center, the #9 piston is ______. See illustration MO-0039. b) on the compression stroke
b
Which of the listed reasons is the most likely cause of a sudden drop in compression pressure in one diesel engine cylinder? b) Malfunctioning valves
b
A diesel engine valve spring is under compression when the valve is ______. I. Open II. Closed c) both I and II
c
Diesel engine valve springs function to ______. c) close the valves
c
Excessively worn, or polished ends on a diesel engine valve spring, indicate ______. c) spring surge
c
In a diesel engine, exhaust valves open before the intake ports are uncovered to ______. I. reduce pumping losses II. reduce back pressure c) both I and II
c
In a diesel engine, the spring force required for proper valve operation is determined by ______. c) cam contour
c
In the chart shown in the illustration, a right hand rotation engine has the #9 piston on top dead center; therefore, the #1 piston is ______. See illustration MO-0039. c) on the power stroke
c
Many diesel engine exhaust valves are being constructed with hollow stems filled with sodium in order to ______. c) assist in dissipating heat due to the extreme operating temperatures
c
The diesel engine component labeled "Z", shown in the illustration is called the ______. See illustration MO-0122. c) exhaust valve bridge
c
The easiest way to locate a defective diesel engine exhaust valves is by ______. c) comparing exhaust pyrometer readings
c
The exhaust valve opens before bottom dead center in a four stroke engine to______. I. allow for blow down II. reduce pumping losses c) both I and II
c
The opening of an exhaust valve on a modern, large, low-speed, main propulsion diesel engine, may be actuated by ______. c) hydraulic "push rods"
c
The purpose of an interference angle in a diesel engine exhaust valve is to ______. I. seat the valve quickly II. break up seat deposits c) both I and II
c
The satisfactory operation of diesel engine exhaust valves usually depends on ______. c) correct timing and proper seating
c
The valve shown in the illustration operates by which of the following principles? See illustration MO-0066. c) Hydraulic pressure opens the valve.
c
The valve stem expansion associated with engine warm-up is allowed for by the ______. c) valve lash adjusters
c
Valve rotators are commonly used on which of the listed diesel engine cylinder head valves? c) Exhaust
c
Valves in the cylinder head of a diesel engine are opened by the direct action of the ______. c) rocker arm movement
c
When one cylinder has a lower compression pressure and higher exhaust gas temperature than any of the other engine cylinders, which of the conditions listed will be indicated? c) Leaky exhaust valve
c
Worn diesel engine intake valve guides can result in ______. c) excessive lube oil consumption
c
A diesel engine exhaust valve spring is under compression when ______. a) the valve is open b) the piston is at top dead center c) the valve is closed d) all of the above
d
A sudden drop in compression pressure in one cylinder of a diesel engine can be caused by ______. d) malfunctioning valves
d
A sudden drop in diesel engine cylinder compression pressure can be caused by ______. d) malfunctioning valves
d
Diesel engine exhaust valve springs are under compression when the valves are ______. d) in any position
d
From the chart shown in the illustration, if a right hand rotation engine had the #9 piston on top dead center, the #8 piston would be on the ______. See illustration MO-0039. d) power stroke
d
If you were inspecting the valve springs on an auxiliary diesel engine, your best indication of impending spring failure would be ______. d) cracks in the surface of the spring
d
In a diesel engine, with the valves set to specification, the shape of the cam determines the valve ______. a) point of opening b) speed of opening c) lift from its seat d) all of the above
d
In a four-stroke/cycle diesel engine, badly worn intake valve guides can cause excessive ______. d) lube oil consumption
d
In comparison to exhaust valves, intake valves of diesel engines may be fabricated from low-alloy mild steels because ______. d) intake valves operate at lower temperatures due to the cooling effect of the intake air flow across the valve
d
In comparison to exhaust valves, intake valves of diesel engines may be fabricated from low-alloy steels because ______. d) intake valves are less affected by the corrosive action of exhaust gases
d
In comparison to exhaust valves, intake valves of diesel engines may be fabricated from low-alloy steels because ______. d) intake valves operate at much lower temperatures and are less affected by the corrosive action of exhaust gases
d
The device shown in the illustration is opened by force as provided by ______. See illustration MO-0066. d) hydraulic pressure
d
The device shown in the illustration may be closed by using pressurized air on some recently built large low speed engines and would replace the component identified as ______. See illustration MO-0066. d) "F"
d
The diesel engine component labeled "1", shown in the illustration is called a/an ______. See illustration MO-0122. d) exhaust valve spring
d
The diesel engine rocker arms shown in the illustration serve to ______. See illustration MO-0122. d) open the exhaust valves and operate the unit injectors
d
The inlet valves for the diesel engine shown in the illustration are indicated by the letter or number ______. See illustration MO-0122. a) "2" b) "19" c) "H" d) none of the above are correct
d
The opening of an exhaust valve on a modern, large, low-speed, main propulsion diesel engine, may be actuated by ______. d) direct hydraulic pressure
d
The rocker arms of the diesel engine shown in the illustration are indicated by ______. See illustration MO-0122. d) "C" and "Y"
d
Valve cages are used on some large diesel engines to ______. d) facilitate valve removal for servicing
d
What will cause valve stem blow-by to the valve section shown in the illustration? See illustration MO-0030. d) Defective rubber seal rings in the valve guides.
d
When checking the underside of the valve cover shown in the illustration, you find localized black patches. You should suspect ______. See illustration MO-0043. d) worn exhaust valve guides and seals
d
Which of the following statements is true concerning the cylinder head and valve assembly of the diesel engine illustrated? See illustration MO-0013. d) Both exhaust valves are opened simultaneously by the valve bridge.
d
Which of the following statements is true concerning the diesel engine valve gear shown in the illustration? See illustration MO-0013. a) Both exhaust valves are operated simultaneously from one rocker arm by a valve bridge. b) Valve lash is mechanically adjusted. c) The engine head is fitted with replaceable valve seats. d) All of the above.
d
Which of the listed conditions will occur if a diesel engine exhaust valve is leaking? a) Loss of compression for that cylinder b) Misfiring or rough running c) Damage to the valve d) All of the above
d
Which of the listed construction characteristics is apparent of the diesel engine shown in the illustration? See illustration MO-0005. d) Valve lash is mechanically adjusted.
d
