Unit 4 Chapter 13 & 14

Front 1

Modern engine oil-control piston ring designs include:

Back 1

Three-piece rings.

Front 2

The __________ is the difference between the volume in the combustion chamber above the piston when the piston is at bottom dead center and the volume of the combustion chamber above the piston when the piston is at top dead center.

Back 2

Compression ratio

Front 3

Piston compression rings must have proper:

(3)

Back 3

End gap, Back clearance, and ring tension.

Front 4

Technician A says that oil passageways drilled in the crankshaft carry oil from the main bearing journals to the rod journals.Technician B says bearings can be undersized or standard. Who is correct?

Back 4

Both Tech A and B

Front 5

Cracks in cast-iron parts are commonly detected by a process called:

Back 5

Magnafluxing.

Front 6

Zyglo is a:

Back 6

Crack-detection dye for metals.

Front 7

Typical clearance for a floating piston pin is:

Back 7

0.0004" to 0.0008".

Front 8

Technician A says hardened valve seats cause valve seat regression.Technician B says hardened seats are necessary in aluminum heads. Who is correct?

Back 8

Tech B

Front 9

Technician A says the fillet area of the crankshaft is where the rod bearing journal meets the crankshaft. Technician B says the journal area of the crankshaft is where the flywheel or flexplate bolts up. Who is correct?

Back 9

Tech A

Front 10

Technician A says some heavy-duty and performance cranks use nitriding. Technician B says nitriding produces a harder, more durable surface than induction hardening. Who is correct?

Back 10

Both Tech A and B

Front 11

Technician A says the asymmetrical design of some in-line four-cylinder and 90-degree V6 engines causes an inherent second-order vibration. Technician B says V8 engines typically use one or two balance shafts to reduce vibrations from engine operation. Who is correct?

Back 11

Tech A

Front 12

Which of the following is a typical shape for tops of pistons?

A. Concave

B. Domed

C. Flat

D. All of the answers listed

Back 12

D. All of the answers listed

Front 13

Two technicians are discussing piston slap. Technician A says piston slap is more noticeable when the pistons are cold. Technician B says piston slap occurs as the piston pivots on the pin near top dead center. Who is correct?

Back 13

Both Tech A and B

Front 14

Technician A says crankshaft bearings are split in two parts, each with a tang that fits into the bearing saddle and cap. Technician B says that automotive crankshaft bearings are typically of the needle bearing type. Who is correct?

Back 14

Tech A

Front 15

Technician A says all main bearings and rod bearings are held in place by what is called bearing crush. Technician B says each main bearing receives its own oil under pressure from the oil hole in the main bearing saddle. Who is correct?

Back 15

Both Tech A and B

Front 16

Cylinder hones can be all of the following types, EXCEPT:

A. rigid.

B. flexible.

C. ball style.

D. tapered.

Back 16

D. tapered.

Front 17

After bead-blasting engine parts:

Back 17

The parts must be thoroughly cleaned to remove any leftover beads.

Front 18

A used engine that is within specs for reusing the pistons will usually have a polished glaze that must be removed. Technician A says to use a boring bar. Technician B says to use a cylinder hone of the proper grit. Who is correct?

Back 18

Tech B

Front 19

Technician A says an outside micrometer is used to measure piston pin diameter. Technician B says the small ends of connecting rods are measured with a bore gauge or inside micrometer. Who is correct?

Back 19

Both Tech A and B

Front 20

A Welch plug is a:

Back 20

Type of soft, round metal disc pressed into the engine block to plug water jackets or passageways.

Front 21

Technician A says that when removing the pistons, you must first remove the piston rings. Technician B says that cracks in a cylinder can be measured with a dial indicator, and are OK as long as they are less than 0.003" wide. Who is correct?

Back 21

Neither

Front 22

Technician A says that using a thicker head gasket would lower the compression ratio. Technician B says that the effective compression ratio is affected by valve timing. Who is correct?

Back 22

Both Tech A and B

Front 23

Technician A says that most pistons use one compression ring and one oil control ring. Technician B says that most pistons use two compression rings and one oil control ring. Who is correct?

Back 23

Tech B

Front 24

Technician A says that fractured rods have a unique mating surface and that only the cap that was fractured is the one that will fit that rod. Technician B says that a powdered metal rod is less expensive, lighter, and as strong as a forged rod. Who is correct?

Back 24

Both Tech A and B

Front 25

Technician A says that the thrust bearing should be aligned by tapping the crankshaft forward and backward before tightening the main bearing cap. Technician B says that the thrust bearing is located on the flywheel. Who is correct?

Back 25

Tech A

Front 26

Technician A says that a failed harmonic balancer can cause a crankshaft to break. Technician B says that the crankshaft rod journals are typically measured using a dial indicator. Who is correct?

Back 26

Tech A

Front 27

Technician A says that a piston is manufactured slightly oval in shape. Technician B says that the piston pin is slightly oval in shape to allow for heat expansion and lubrication. Who is correct?

Back 27

Tech A

Front 28

Technician A says that cylinder walls are manufactured with a slight taper so that the piston rings will seal tighter at TDC. Technician B says that piston coatings assist in the control of piston temperature, which allows for tighter bore clearances and greater engine efficiency. Who is correct?

Back 28

Tech B

Front 29

Technician A says that main and rod bearings are glued in place with special bearing cement. Technician B says that main and rod bearings are held in place by a precise amount of “bearing crush.” Who is correct?

Back 29

Tech B

Front 30

Technician A says that when grinding main journals, an undersized main bearing will be required. Technician B says that the main bearing journals should be measured for minimum diameter, out-of-round, and taper. Who is correct?

Back 30

Both Tech A and B

Front 31

Technician A says the proper crosshatch pattern is critical for proper lubrication of the pistons and rings. Technician B says that the smoother the cylinder walls, the better the rings will seal. Who is correct?

Back 31

Tech A

Front 32

Technician A says that main bearing clearance can be calculated by knowing the inner diameter of the main bearing and the outer diameter of the main journal. Technician B says that rod bearing and main bearing clearance can be measured with Plastigauge. Who is correct?

Back 32

Both Tech A and B

Front 33

Technician A says that after using a portable boring bar, the cylinder bore will need to be honed by 0.0015" to 0.002". Technician B says that the portable boring bar is the best way to go as it can be used on all current engines. Who is correct?

Back 33

Neither

Front 34

Technician A says that when boring a cylinder, it should be bored to the final cylinder size. Technician B says that it should be bored smaller than the final size to allow for honing of the cylinder. Who is correct?

Back 34

Tech B

Front 35

Technician A says that Ra is critical in the machining process to ensure gasket sealing. Technician B says that a Ra rating of 0-1 is the best sealing surface. Who is correct?

Back 35

Tech A

Front 36

Technician A says that failure analysis will assist the technician in making an estimate of repairs. Technician B says that failure analysis will help prevent reoccurrence of the problem. Who is correct?

Back 36

Both Tech A and B

Front 37

Technician A says that a torque plate bolts to the bottom of the block to strengthen the block when boring. Technician B says that the use of a torque plate compensates for the cylinder head being torqued in place. Who is correct?

Back 37

Tech B

Front 38

Technician A says that bearing crush is when the main caps are torqued and the bearing is crushed against the crankshaft. Technician B says that crankshaft journals can be machined undersize and undersized bearings can be used. Who is correct?

Back 38

Tech B

Front 39

Technician A says that when measurement of the cylinder bore is out of specifications, just install an oversized piston. Technician B says that cylinders can typically be bored out to only a few specific sizes. Who is correct?

Back 39

Tech B

Front 40

Technician A says that full floating pistons use keepers to retain the piston pin. Technician B says that some piston pins are press-fit in the rod. Who is correct?

Back 40

Both Tech A and B

Front 41

A typical dry sleeve is held in place by a(n) _____________________ with the cylinder walls.

Back 41

interference fit

Front 42

All of the following parts may be found on, or fastened to, a modern crankshaft, EXCEPT:

A. a crankshaft position sensor reluctor.

B. a torque converter flex plate.

C. a flywheel.

D. a wrist pin.

Back 42

D. a wrist pin.

Front 43

On a gasoline engine, what is a typical type of cylinder found in a new cast iron block?

Back 43

Machined directly into the block

Front 44

Technician A says the main role of the crankshaft is to transfer the up-and-down strokes of the pistons into rotary motion. Technician B says the crankshaft is situated in the cylinder head. Who is correct?

Back 44

Technician A

Front 45

The quickest tool to measure a cylinder bore is a(n):

Back 45

dial bore gauge.

Front 46

Typical clearance for a floating piston pin is:

Back 46

0.0004" to 0.0008".

Front 47

Crankshafts:

A. use Woodruff keys

B. use square-cut keys

C. have a sealing surface

D. All of the answers listed

Back 47

D. All of the answers listed

Front 48

Technician A says hardened valve seats cause valve seat regression. Technician B says hardened seats are necessary in aluminum heads. Who is correct?

Back 48

Technician B

Front 49

When testing cylinder heads, Technician A says magnafluxing or dye checking is used to locate any external cracks. Technician B says pressure testing is used to locate any internal cracks. Who is correct?

Back 49

Both Technician A and Technician B

Front 50

Two technicians are discussing cylinder preparation after honing to the correct crosshatch pattern has been performed. Technician A says to first clean the cylinder walls with solvent; then scrub them with warm, soapy water and a stiff brush to remove any metal and stone particles. Technician B says to first take a shop rag and pour some clean oil on it; then rub the oil into the cylinder walls. Who is correct?

Back 50

Technician A

Front 51

What is the most common coating for pistons?

Back 51

Black moly coating

Front 52

Technician A says the oil control rings prevent excessive oil from working up into the combustion chambers. Technician B says the oil control ring is always a one-piece ring. Who is correct?

Back 52

Technician A

Front 53

Which type of wrist pin can be installed by hand?

Back 53

Floating pin

Front 54

The most common piston arrangement has:

Back 54

two thin compression ring grooves and one large oil ring groove.

Front 55

Stock gasoline engine compression ratios typically run between:

Back 55

8:1 to 10.5:1

Front 56

A type of soft, round metal disc pressed into the engine block to plug water jackets or passageways.

Back 56

Welch plug

Front 57

Technician A says when rebuilding an engine, used pistons must have no cracks, acceptable ring land wear and acceptable skirt wear in order to be reused. Technician B says that if the piston skirts are worn too much the pistons will make a screeching noise. Who is correct?

Back 57

Technician A

Front 58

What allow(s) exact alignment of the cylinder head and cylinder head gasket when reassembling the engine assembly?

Back 58

Engine block dowel pin hole

Front 59

Two technicians are discussing cylinder honing. Technician A says a good crosshatch helps to trap the oil and retain it in the cylinder bore where it is needed. Technician B says most hones are self-tensioning, which alleviates the need for the technician to determine the amount of tension needed. Who is correct?

Back 59

Both Tech A and B

Front 60

Two technicians are discussing engine work. Technician A says the manufacturer's specifications for the main bearing bore diameter must be followed when line honing to ensure that the proper oil clearance is established between the bearings and the crankshaft main journals. Technician B says you should line-hone the bearing bores .010" undersize to increase engine oil pressure. Who is correct?

Back 60

Technician A

Front 61

Which of the following finishes is left in a cylinder after honing?

Back 61

Crosshatch pattern

Front 62

Which of the following is typically used when a cylinder only needs to be deglazed?

Back 62

Ball hone

Front 63

A boring bar is used to:

Back 63

cut the cylinders to their new oversized dimensions.

Front 64

When testing cylinder heads, Technician A says magnafluxing or dye checking is used to locate any external cracks. Technician B says pressure testing is used to locate any internal cracks. Who is correct?

Back 64

Both Technician A and Technician B

Front 65

The _______________ gets its name because it is in direct contact with the water jacket.

Back 65

wet sleeve

Front 66

Which of the following is typically used to correct for a main bearing bore alignment issue?

Back 66

Line boring

Front 67

Which of the following is a style of boring bar?

A. Portable boring bar

B. Semi-automatic boring bar

C. Computer numerical control (CNC) boring machine

D. All of the answers listed

Back 67

D. All of the answers listed

Front 68

Technician A says virtually all production engines are pre-balanced before leaving the factory. Technician B says cylinder head resurfacing should be performed if the head has internal cracks. Who is correct?

Back 68

Technician A

Front 69

What should be done if the cylinder bore is damaged beyond the boring limits for that engine?

Back 69

Bore the cylinder out and install a sleeve.

Front 70

Which of the following allows exact alignment of the cylinder head and cylinder head gasket when reassembling the engine assembly?

Back 70

Engine block dowel pin hole.

Front 71

The _________ is approximately 2 inches thick and bolts in place where the cylinder head is fastened on to the engine block.

Back 71

Torque Plate

Front 72

Which of the following is a typical condition caused by cylinder glazing?

Back 72

Increased oil consumption

Front 73

When weight is needed to be added to a crankshaft during balancing:

Back 73

use Mallory metal plugs.

Front 74

Technician A says the wrist pin is typically held in place with an Allen screw on each side of the piston pin boss. Technician B says some floating wrist pin designs use a bushing on the small end of the connecting rod. Who is correct?

Back 74

Technician B

Front 75

Most crankshafts are:

Back 75

nitriding hardened

Front 76

Technician A says the dry method of checking for cracks in a cast iron head uses iron dusting powder. Technician B says the wet method uses a liquid iron and fluorescent dye mixture. Who is correct?

Back 76

Both Tech A and B