Deck 33: Pistons, Rings, and Connecting Rods

Question 1

A hypereutectic piston ________.

A)Is a cast piston
B)Uses about 16% silicon
C)Is a forged piston
D)Both A and B

Answer 1

Both A and B

Question 2

Many aluminum piston skirts are plated with ________.

A)Terneplate
B)Lead
C)Tin or moly graphite
D)Antimony

Answer 2

Tin or moly graphite

Question 3

A hypereutectic piston has a higher ________.

A)Nickel content
B)Tin content
C)Silicon content
D)Weight than an aluminum piston

Answer 3

Silicon content

Question 4

The purpose of casting steel struts into an aluminum piston is to ________.

A)Provide increased strength
B)Provide increased weight at the top part of the piston where it is needed for stability
C)Control thermal expansion
D)Both A and C

Question 5

Full floating piston pins are retained by ________.

A)An interference fit between rod and piston pin
B)Lock rings
C)A drilled hole with a roll pin
D)An interference fit between piston and piston pin

Question 6

The space behind the piston ring is called ________.

A)Side clearance
B)Back clearance
C)Piston ring clearance
D)Forward clearance

Question 7

A misaligned connecting rod causes what type of engine wear?

A)Diagonal wear on the piston skirt
B)Barrel-shaped cylinders
C)Cylinder taper
D)Ridge wear

Question 8

Side clearance is a measure taken between the ________ and the ________.

A)Piston (side skirt); cylinder wall
B)Piston ring; piston ring groove
C)Compression ring; oil control ring
D)Piston pin; piston pin retainer (clip)

Question 9

Piston ring gap should only be measured after ________.

A)Installing the rings on the piston
B)Installing the piston in the cylinder
C)All cylinder work has been performed
D)Both A and C

Question 10

Which type of connecting rod needs to be heated to install the piston pin?

A)Interference fit
B)Floating
C)Forged
D)PM rods

Question 11

Technician A says that the connecting rods should be marked before disassembly. Technician B says that pistons are cam ground so that when operating temperature is reached, the piston will have expanded enough across the piston pin area to become oval shaped. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 12

Technician A says that replacement pistons can be of different weights from the original pistons. Technician B says that some engines use an offset piston pin to help reduce piston slap when the engine is cold. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 13

Technician A says that if the ring end gap is excessive, blowby gases can travel past the rings and into the crankcase. Technician B says that piston rings usually include three compression rings at the top of the piston and an oil control ring below the compression rings. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 14

Technician A says that powdered metal connecting rods cannot be reconditioned and must be replaced if damaged or worn. Technician B says that the piston and the connecting rod must be correctly assembled according to identifying notches or marks. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 15

All of the following are methods of piston to rod attachment EXCEPT ________.

A)Woodruff key
B)Full floating
C)Free floating
D)Press fit to rod

Question 16

Cam ground pistons, as they warm up, take on which of these shapes?

A)Round
B)No change
C)Tapered
D)Oval

Question 17

Technician A says that chrome rings are the best rings to use in an unbored cylinder. Technician B says that ring end gap is non-adjustable; therefore there is no need to check it when reassembling the engine. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 18

Some connecting rods have ________ to help lubricate the cylinder wall or piston pin.

A)Spit holes
B)Three rod bolts
C)Drip valves
D)Graphite coatings

Question 19

A full-floating piston pin is held in place using ________.

A)Glue
B)Snap rings
C)Friction
D)Cotter pins

Question 20

It is normal for a powdered metal connecting rod to have a cracked parting line.

Question 21

In this drawing, which is the side clearance?

A)B
B)A
C)Neither A nor B
D)Either A or B

Question 22

What is the technician doing in this photograph?

A)Measuring back clearance
B)Measuring side clearance
C)Cleaning the rings
D)Measuring end gap