Question 1

What is the brand name ofthe largest manufacturer of forged steel trunk pistons used in commercial diesel engines?

Accepted Answer

A)   Caterpillar
B)   Cummins
C)   Monotherm
D)   FerrothermE) B) and C)
F) None of the above

Question 2

Which of the following do current forged steel trunk type pistons primarily depend on to lubricate the wrist pins?

Accepted Answer

A)   lube oil delivered through conn rod rifle
B)   splash lube from oil sump
C)   spray cooling jets
D)   lube transfer from cylinder wallE) None of the above
F) A) and D)

Question 3

Which of the following ring arrangements would be most common on current medium and large bore truck diesel engines?

Accepted Answer

A)   one compression, one oil control
B)   two compression, one oil control
C)   three compression, two oil control
D)   four compression, two oil controlE) A) and B)
F) A) and C)

Question 4

What is diametrically opposite to the piston major thrust face?

Accepted Answer

A)   pin boss
B)   cylinder head
C)   anti-thrust face
D)   crankshaftE) None of the above
F) A) and C)

Question 5

How would a Mahle Monotherm piston be described?

Accepted Answer

A)   aluminum trunk piston
B)   forged steel trunk piston
C)   composite steel trunk piston
D)   steel and aluminum articulating pistonE) B) and D)
F) A) and B)

Question 6

Technician A says that Monotherm pistons feature a bushingless wrist pin bore. Technician B says that forged steel pistons are usually equal in weight to equivalent bore aluminum trunk pistons because much less material is used in their construction. Who is correct?

Accepted Answer

A)   Technician A only
B)   Technician B only
C)   Both A and B
D)   Neither A nor BE) A) and C)
F) A) and D)

Question 7

Which of the following piston types is the most common in large bore highway diesel engines built after 2007?

Accepted Answer

A)   aluminum trunk
B)   forged steel trunk
C)   crosshead articulating
D)   full articulatingE) C) and D)
F) B) and D)

Question 8

Which of the following is generally a disadvantage of an articulating piston assembly when compared to an aluminum trunk piston?

Accepted Answer

A)   piston slap
B)   thermal distortion
C)   longevity
D)   weightE) A) and B)
F) C) and D) D

Question 9

Technician A says that Monotherm pistons are manufactured with a much tighter fit to the liner bore than aluminum trunk pistons. Technician B says that Monotherm pistons do not require an oil spray jet aimed at the underside of the piston. Who is correct?

Accepted Answer

A)   Technician A only
B)   Technician B only
C)   Both A and B
D)   Neither A nor BE) B) and C)
F) C) and D)

Question 10

Which of the following is a major advantage of using quiescent combustion dynamics in truck diesel engine?

Accepted Answer

A)   increases engine power
B)   reduces afterburn and soot emissions
C)   requires increased injection pressures
D)   simplifies piston crown designE) A) and B)
F) A) and C) B

Question 11

What is PlastigageTM used for measuring?

Accepted Answer

A)   crankshaft endplay
B)   big end side play
C)   friction bearing clearance
D)   flywheel runoutE) A) and D)
F) B) and D) C

Question 12

What is used to retain friction bearings?

Accepted Answer

A)   tangs
B)   spread
C)   thrust
D)   crushE) B) and D)
F) All of the above

Question 13

Which of the following identifies the correct companion cylinder pairings in an in-line 6-cylinder engine?

Accepted Answer

A)   1 - 2, 3 - 4, 5 - 6
B)   1 - 5, 3 - 6, 2 - 4
C)   1 - 6, 2 - 5, 3 - 4
D)   6 - 5, 4 - 3, 2 - 1E) A) and B)
F) B) and C)

Question 14

A viscous type vibration damper shows trace fluid leakage. Which of the following is recommended?

Accepted Answer

A)   seal with silicone
B)   check with a balance sensor
C)   repair weld the crack
D)   replacementE) A) and B)
F) A) and C)

Question 15

Which of the following piston types is likely to be cam ground?

Accepted Answer

A)   aluminum trunk
B)   two piece crosshead
C)   two piece articulating
D)   ceramic headlandE) A) and B)
F) B) and C)

Question 16

Technician A says that the upside of a piston ring is often identified by a dot. Technician B measures a ring end gap of 0.018 inch in 5-inch diameter cylinder bore and says that it almost certainly exceeds the OEM specification. Who is correct?

Accepted Answer

A)   Technican A only
B)   Technican B only
C)   Both A and B
D)   Neither A nor BE) All of the above
F) A) and D)

Question 17

Which of the following best describes the sectional shape of a keystone ring?

Accepted Answer

A)   oval
B)   round
C)   rectangular
D)   wedgeE) All of the above
F) C) and D)

Question 18

Which of the following features would be required in an aluminum alloy, trunk type piston when used in a commercial diesel engine application?

Accepted Answer

A)   full floating wrist pin
B)   ring groove insert (Ni-Resist) 
C)   chromed pin boss
D)   tin platingE) B) and D)
F) All of the above

Question 19

Which of the following would be the most likely cause of a connecting rod tensile failure?

Accepted Answer

A)   engine overspeed
B)   excess ether usage
C)   high cylinder pressures
D)   drive train shock loadE) All of the above
F) A) and D)

Question 20

Where is a piston ring installed in the piston assembly?

Accepted Answer

A)   pin boss
B)   ring groove
C)   ring land
D)   crownE) All of the above
F) C) and D)

Exam 7: Engine Powertrain Components

What is the brand name ofthe largest manufacturer of forged steel trunk pistons used in commercial diesel engines?

Correct AnswerverifiedShow Answer

Which of the following do current forged steel trunk type pistons primarily depend on to lubricate the wrist pins?

Correct AnswerverifiedShow Answer

Which of the following ring arrangements would be most common on current medium and large bore truck diesel engines?

Correct AnswerverifiedShow Answer

What is diametrically opposite to the piston major thrust face?

Correct AnswerverifiedShow Answer

How would a Mahle Monotherm piston be described?

Correct AnswerverifiedShow Answer

Technician A says that Monotherm pistons feature a bushingless wrist pin bore. Technician B says that forged steel pistons are usually equal in weight to equivalent bore aluminum trunk pistons because much less material is used in their construction. Who is correct?

Correct AnswerverifiedShow Answer

Which of the following piston types is the most common in large bore highway diesel engines built after 2007?

Correct AnswerverifiedShow Answer

Which of the following is generally a disadvantage of an articulating piston assembly when compared to an aluminum trunk piston?

Correct AnswerverifiedD

Technician A says that Monotherm pistons are manufactured with a much tighter fit to the liner bore than aluminum trunk pistons. Technician B says that Monotherm pistons do not require an oil spray jet aimed at the underside of the piston. Who is correct?

Correct AnswerverifiedShow Answer

Which of the following is a major advantage of using quiescent combustion dynamics in truck diesel engine?

Correct AnswerverifiedB

What is PlastigageTM used for measuring?

Correct AnswerverifiedC

What is used to retain friction bearings?

Correct AnswerverifiedShow Answer

Which of the following identifies the correct companion cylinder pairings in an in-line 6-cylinder engine?

Correct AnswerverifiedShow Answer

A viscous type vibration damper shows trace fluid leakage. Which of the following is recommended?

Correct AnswerverifiedShow Answer

Which of the following piston types is likely to be cam ground?

Correct AnswerverifiedShow Answer

Technician A says that the upside of a piston ring is often identified by a dot. Technician B measures a ring end gap of 0.018 inch in 5-inch diameter cylinder bore and says that it almost certainly exceeds the OEM specification. Who is correct?

Correct AnswerverifiedShow Answer

Which of the following best describes the sectional shape of a keystone ring?

Correct AnswerverifiedShow Answer

Which of the following features would be required in an aluminum alloy, trunk type piston when used in a commercial diesel engine application?

Correct AnswerverifiedShow Answer

Which of the following would be the most likely cause of a connecting rod tensile failure?

Correct AnswerverifiedShow Answer

Where is a piston ring installed in the piston assembly?

Correct AnswerverifiedShow Answer

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D

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B

What is Plastigage^TM used for measuring?

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C

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