Deck 3: Cylinder Block Assemblies

Question 1

What is piston slap?

A) The piston contacting the valves at high revs.
B) Loose wrist pins chattering when the engine is cold.
C) Late combustion in cold engines causing a slapping noise.
D) Tilting of the piston when it is thrust loaded by cylinder combustion pressure.

Answer 1

D

Question 2

What is a disadvantage of cam-ground pistons?

A) Poor heat transfer.
B) Can be damaged when cold if subject to heavy loads.
C) They require reinforcement at the pin boss resulting in a heavier piston.
D) Short service life.

Answer 2

B

Question 3

When replacing defective connecting rods what should a technician make sure of?

A) That the new rod matches the weight code of the damaged rod.
B) The new rod is made from the same batch code.
C) The new rod comes with a new wrist pin.
D) Both rods have the same general shape.

Answer 3

A

Question 4

What are the three piston oil cooling methods?

A) Pressurized, ambient and vacuum.
B) Shaker, circulation and spray.
C) Active, passive and indirect.
D) Using lube oil, fuel or exhaust fluid (DEF).

Question 5

What is the minor thrust face sometimes called?

A) Anti-thrust face.
B) Leading-thrust face.
C) Pivot-thrust face.
D) Small-thrust face.

Question 6

What force is primarily responsible for piston ring seal?

A) Cylinder pressure.
B) Radial ring pressure.
C) Crankcase pressure.
D) Oil viscosity.

Question 7

What is the wall section of the piston where the piston rings are located called?

A) Top land.
B) Ring belt.
C) Ring dome.
D) Compression grooves.

Question 8

What functions are performed by piston rings?

A) Sealing only.
B) Pressurizing only.
C) Lubrication only.
D) Sealing, lubrication and cooling.

Question 9

Why is piston ring control of cylinder wall oil film important on current engines?

A) Aluminum cylinder walls must be kept lubricated.
B) Oil must be delivered to the combustion chamber for cooling.
C) Current engines must maintain higher compression levels.
D) Excess oil on cylinder walls adversely effects exhaust emissions.

Question 10

Which of the following is true of barrel faced piston rings?

A) Increased service life but a less effective seal.
B) Lower cost and easier to install.
C) A less effective seal but better heat transfer.
D) A better seal and increased service life.

Question 11

What ring configuration is used in most current automotive diesel engines?

A) Three rings, two compression and one oil control.
B) Three rings, compression, cooling and oil control.
C) Three rings, one compression and two oil control.
D) A single multi-purpose ring.

Question 12

What is the practice of fracturing the big end of a connecting rod is referred to as?

A) Absolute zero rod technology.
B) Snapped rod technology.
C) Broken rod technology.
D) Cracked rod technology.

Question 13

The lower region of the engine is known as?

A) Cylinder block.
B) Head.
C) Engine block.
D) Crankcase.

Question 14

What type of piston is best at overcoming engine slap?

A) Mexican hat crowned pistons.
B) Aluminum pistons
C) Forged steel trunk type pistons.
D) Cam ground pistons.

Question 15

What is the function of the engine powertrain?

A) Cranking and power supply.
B) Compressing and ignition.
C) Converting cylinder gas pressure into torque at the flywheel.
D) Manages the electrical systems.

Question 16

Why is lubricant spayed onto the underside of aluminum pistons?

A) To assist in keeping piston crown temperatures lower.
B) To lower ignition temperatures.
C) Because moving cylinders provide splash circulation of oil.
D) It is the only method available to lubricate wrist pins.

Question 17

In what position are combination compression/scraper rings located?

A) Just above the oil drain holes.
B) In the middle of the ring belt, below the compression ring and above the oil rings.
C) In the bottom ring groove below any oil rings.
D) In the top ring groove.

Question 18

What are pistons manufactured from a single piece of metal called?

A) Crown pistons.
B) Trunk-type pistons.
C) Ceramic pistons.
D) Cast iron pistons.

Question 19

What is a short block overhaul?

A) Overhauling of a small engine.
B) Replacement of just the power train components.
C) Overhauling of just the cylinder block.
D) Replacement of the engine cylinder block assembly.

Question 20

Under what conditions is ring end gap is checked?

A) The engine is at operating temperature.
B) With the engine cold but the rings and cylinder warmed.
C) The engine and ring are both cold.
D) With the combustion chamber pressurized.

Question 21

Technician A states that a ni-resist insert is a groove insert used on aluminum trunk type pistons. Technician B states ni-resist inserts are often used in the oil ring grooves. Who is correct?

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