Deck 4: Cylinder Blocks and Crankshafts

Question 1

Which of the following is the primary reason for locating geartrains on the rear of the engine?

A)To minimize engine noise.
B)To ease of service.
C)To make it easier to mount accessories such as power steering pumps and air compressors.
D)To minimize engine torsional vibrations.

Answer 1

A

Question 2

Technician A says that rear geartrains are used to shorten the length of the engine block. Technician B says that rear geartrains reduce engine vibration. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Answer 2

D

Question 3

What type of tapped threads is most commonly used in cylinder block castings?

A)Fine.
B)Coarse.
C)Rolled.
D)Metric and imperial

Answer 3

B

Question 4

Which of the following is the manufacturer's purpose for core plugs?

A)To clean sand from blocks after casting.
B)To install block heaters.
C)To prevent freezing damage to cylinder blocks.
D)To add inspection holes for internal block castings.

Question 5

The lightest, strongest, and quietest engine blocks are _________.

A)made from aluminum
B)parent bore blocks
C)dry sleeve blocks
D)made from compacted graphite iron (CGI)

Question 6

Technician A says that cast-in-place iron liners are commonly used in aluminum cylinder blocks. Technician B says that only closed-deck blocks will use cast iron liners. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 7

Which of the following is the purpose of bolster bolts or tie bolts?

A)To hold the main bearing caps down tightly.
B)To reduce torsional vibrations.
C)To increase engine block rigidity and strength.
D)To secure the crankcase bedplate to the engine block.

Question 8

Which of the following features will a ladder-frame engine block have?

A)A block skirt extending past the main bearing caps.
B)A steel plate bolted to the oil pan rail and main bearing caps.
C)Main bearing caps integrated into a one-piece casting.
D)A lightweight engine block.

Question 9

While examining a thick, heavy, flat steel plate bolted to the oil pan rails and main bearing caps, Technician A suggests it is used to stiffen the crankcase to reduce torsional twisting. Technician B says the plate is used to prevent oil from splashing up onto the cylinder walls and causing high oil consumption. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 10

The presence of cavitation on a replaceable cylinder liner is most likely caused by ___________.

A)liner vibration
B)low cylinder pressures
C)excessive cooling system pressure
D)improperly conditioned coolant

Question 11

Technician A says that polished cylinder walls will cause low power and more blowby. Technician B says cylinder walls with more than 90% remaining crosshatch have less than 50% remaining service life. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 12

V8 engines have cylinder banks arranged at which of the following angles to allow for even crankshaft rotation between firing impulses?

A)60°.
B)90°.
C)37.5°.
D)45°.

Question 13

Crankshaft counterweights are used to minimize engine vibration caused by which of the following?

A)The inertia of the piston/connecting rod assembly.
B)Uneven firing impulses.
C)Torsional vibration.
D)Angular velocity changes of the crankshaft.

Question 14

Technician A says that nitriding bearing journal surfaces produces the deepest amount of crankshaft hardening. Technician B says that induction hardening produces the hardest journal finish. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 15

Torsional vibration resulting in "jumped" accessory drive belts, excessive geartrain wear, and broken camshafts is commonly the result of which of the following defective components?

A)Dual mass flywheel (DMF).
B)Vibration dampener.
C)Imbalanced crankshaft.
D)Balance shaft.

Question 16

Technician A says that a defective vibration dampener will cause the accessory drive belts of an engine to jump off the drive pulleys. Technician B says a defective vibration dampener will cause the crankshaft or even the camshaft to break. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 17

After discovering coolant is leaking into the engine oil, Technician A says the leak will rapidly accelerate cylinder wall wear. Technician B says the coolant leak is likely casue more damage to engine bearings first. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 18

Technician A says that Plastigauge that becomes wider indicates a smaller oil clearance between a crankshaft and main bearing. Technician B says the Plastigauge will become narrower when bearing oil clearances are smaller. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 19

While installing new rod bearing inserts, the shells protruded very slightly above the margin of the bearing cap. Technician A says this is normal. Technician B says that wrong bearings produce this result. Who is correct?
​

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 20

Technician A says that crankshaft end play is controlled by the fillet radius of the crankshaft journals. Technician B says that the main bearings limit crankshaft end play. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 21

Two technicians are discussing diesel engine block design. Technician A says that the diesel's high cylinder pressure produces extraordinary vibration that requires a unique design. Technician B says that cylinder block has other major parts attached to it. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 22

Which of the following supports cylinders and liners (if equipped) as its primary function?

A)Girdle"
B)Bedplate"
C)Crankshaft
D)Cylinder block"

Question 23

Which of the following does NOT have a diesel engine block cylinder banks configuration?

A)In-line"
B)V-Block"
C)W-Block
D)Horizontally opposed"

Question 24

Technician A says that with each alternating power and compression stroke the crankshaft will slow and then accelerate several times during each revolution. Technician B says that camshaft and crankshaft speed variations are between 10% and 20% during each crank rotation. Who is right?

A)A only"
B)B only"
C)Both A and B
D) Neither A nor B

Question 25

Which of the following is NOT an advantage of cast iron?

A)Absorbs vibration well"
B)Inherently strong"
C)Easy to manufacture
D)Light weight"

Question 26

What portion of the upper cylinder walls is induction hardened by the GM Duramax 6.6 blocks?

A)½"
B)¼"
C)1/3
D)3/4"

Question 27

Two technicians are discussing the use of aluminum in diesel engine blocks. Technician A says that aluminum has an expansion coefficient ten times the rate of iron. Technician B says that aluminum also has challenges in diesel application in terms of rigidity, strength, and reliable bolting of the cylinder head and main bearings. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 28

What is the technique called that ties the cylinder head to the block with steel tie bolts inserted through the bottom of the block?

A)Heli-coils"
B)Thread inserts"
C)Tension bolt design
D)Warp anchor method"

Question 29

Two technicians explain how to increase block rigidity. Technician A says that vibration reduction and increased block rigidity can be further enhanced by adding lines to the deep skirt crankcase walls. Technician B says that adding ribs and webbing to the crankcase area minimizes crankcase distortion causing noise vibration. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 30

When you add curves to the deep skirt crankcase walls to increase block rigidity, it is called:

A)cross-bolted mains"
B)deep skirt block"
C)serpentine convolutions
D)cross-bolted blocks"

Question 31

Which of these takes place when using a crossbolt design to strengthen the crankcase walls?

A)Block height lowers"
B)Block height lowers"
C)Weight reduces
D) Weight increases

Question 32

A ladder frame uses an additional block structure located between the cylinder block and the oil pan which incorporates the main bearing caps into one unit and is called a:

A)serpentine curve"
B)bedplate"
C)girdle
D)cross-bolt bed"

Question 33

What cylinder construction, also known as a no-sleeve block, has holes cast and bored in the block for the cylinders?

A)Parent-bore"
B)Wet-sleeve"
C)Dry-sleeve
D)Cast in place sleeve"

Question 34

Technician A says that cylinder sleeves must be replaced in pairs if they become worn or damaged prematurely. Technician B says that sleeves are commonly used in medium and large bore engines operating under high mileage extended service conditions. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 35

Which of the following is NOT part of a cylinder kit?

A)Pistons"
B)Rings"
C)Liners
D)Rods"

Question 36

What type of dry-liner will use a counter bore machined into the block to accommodate the liner flange?

A)Slip-fit"
B)Interference-fit"
C)Smooth-fit
D)Press-fit"

Question 37

Cylinder walls have a cross hatch finish made by:

A)honing stones"
B)a boring bar"
C)a dial-bore tool
D)a reamer"

Question 38

To reduce the time and distance required for engine break in, manufacturers use a process called:

A)plateau honing"
B)direct honing"
C)reaming
D)boring"

Question 39

Two technicians are describing the reasons for the greatest amount of wear near the top of the cylinder wall, causing taper. Technician A says that higher cylinder pressures near the top part of piston travel increase ring pressure against the cylinder walls. Technician B says a lack of upper cylinder wall lubricant takes place because lubrication oil can only be carried into this area on the face of the compression ring. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 40

Cylinder wear at mid-stroke is a common condition in engines with:

A)high thrust forces"
B)low thrust forces"
C)excessive clearance
D)insufficient clearance"

Question 41

The distance of rod journal offset from the main bearing journals is known as the throw and determines the :

A)bore"
B)stroke"
C)rod length
D)bearing size"

Question 42

When the engine is operating, tremendous inertia forces are generated by the reciprocating mass of the connecting rod and piston assembly. To balance these forces, large counterweights are formed on the crankshaft at _____ degrees opposite the rod journal.

A)90"
B)120"
C)180
D)360"

Question 43

Two technicians are describing the crankshaft induction hardening process. Technician A says that to induction harden a crankshaft, the journal is wrapped in a coil of wire using high amperage with direct current passing through it. Technician B says that the journal surface will have current induced into it by mutual induction, much like the secondary winding of an ignition coil. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 44

Technician A says that undersized bearings are available to service diesel engine forged crankshafts. Technician B says that diesel crankshafts are almost always hardened; and grinding to repair journal damage will remove the surface hardening. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 45

What type of balance is achieved when the movement of one piston counterbalances the movement of another?

A)Primary"
B)Secondary"
C)Controlled
D)Horizontal"

Question 46

The place where the amplitude of the wave form is reversed and formed by harmonic waves along the crank and are points of potential failures due to harmonic vibration is called the:

A)harmonic point"
B)nodal point"
C)stress point
D)load point"

Question 47

Which of the following can substantially suppress torsional vibration at its end of the crankshaft?

A)Flywheel weight"
B)Damper weight"
C)Harmonic rhythm
D)Balance weights"

Question 48

Which of the following is NOT a type of dampener used on diesel engines?

A)Elastomer dampener"
B)Parallel dampener"
C)Rotating pendulum vibration absorber
D)Viscous dampener"

Question 49

What type of dampener uses balance shafts to cancel out rhythmic forces produced by long or uneven delays between firing impulses of an engine?

A)Elastomer dampener"
B)Combination dampeners"
C)Rotating pendulum vibration absorber
D)Viscous dampener"

Question 50

Technician A says that if the marks are not aligned on the two rings of an elastomeric dampener, it is defective. Technician B says that the lines on the outer and inner hub of an elastomeric dampener should always line up. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 51

Two technicians are describing flywheel function. Technician A says that a flywheel provides a mounting surface for a clutch in the case of a manual transmission and a torque converter for automatic transmissions. Technician B says that flywheel shape and construction is the same for any type of clutch used, whether torsional dampening capabilities are built into the flywheel or not. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 52

Technician A says that a dual mass flywheel (DMF) is constructed of two major parts. Technician B says that DMFs are recognized by a series of springs located around the flywheel circumference. Who is right?

A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Question 53

During the inspection of a dual-mass flywheel, you inspect the spring retainer for damage. What do you notice between the springs and nylon retainers that makes you recommend a replacement?

A)Large gap"
B)Small gap"
C)Corrosion
D)No shims"

Question 54

What is measured after the clutch cover is reinstalled during the inspection of a dual mass flywheel?

A)Flywheel freeplay"
B)Clutch endplay"
C)Clutch internal adjustment
D)Clutch brake"

Question 55

As part of the dual-mass flywheel inspection, the secondary plate rock checks the:

A)radial movement"
B)clutch engagement"
C)axial movement
D)rotation"

Question 56

Which of these is the ability of a bearing to allow friction without excessive wear or friction?

A)Embedability"
B)Conformability"
C)Compatibility
D)Fatigue strength"

Question 57

Which of these is the ability of a bearing to conform to irregularities on a journal surface?

A)Embedability"
B)Conformability"
C)Compatibility
D)Fatigue strength"

Question 58

What type of bearings use a construction technique that hardens the bearings overlay surface to increase their durability?

A)Babbit"
B)Copper"
C)Spatter
D)Sputter"

Question 59

Which of the following is NOT a function of engine bearings?

A)Reduce friction"
B)Support moving parts under load"
C)Increase clearance
D)Serve as replaceable wear surfaces"

Question 60

Technician A says that Plastigauge that becomes wider indicates a smaller oil clearance between a crankshaft and main bearing. Technician B says the Plastigauge will become narrower when bearing oil clearances are smaller. Who is correct?

A)Technician A"
B)Technician B"
C)Both A and B
D)Neither A nor B"