Deck 9: Camshafts, Lifters, Timing Belts and Chains

Question 1

Technician A says valve overlap occurs at the bottom of the intake stroke. Technician B says valve overlap occurs at the top of the intake stroke. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Answer 1

B

Question 2

Technician A says sometimes the exhaust lobe on the camshaft will wear quickly and more severely than the intake. Technician B says the roller cam cuts valvetrain friction by 75%. Who is right?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Answer 2

A

Question 3

In reference to fuel use, what is CAFE?

Answer 3

Corporate Average Fuel Economy (CAFE) are the fuel economy standards passed by the United States Congress in 1975.

Question 4

Technician A says on most pushrod engines, lifters have a concave face. Technician B says pushrods are stationary when the engine is running. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 5

Technician A says on a pushrod engine, the lifters do not need to be replaced when the camshaft is replaced. Technician B says when replacing a roller camshaft, the lifters must be replaced. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 6

With regard to gear drives, what is backlash?

Question 7

Technician A says that a gear on the camshaft drives the distributor. Technician B says the exhaust and intake valves each operate on a separate lobe on the camshaft. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 8

The camshaft is the determining factor in how efficiently the engine pumps air.

Question 9

Before using a chain wrench to hold a pulley in order to torque the crank bolt, what should you do?

Question 10

Camshafts are being discussed. Technician A says cam journals rarely wear so they do not need to be reground. Technician B says reground cams are more expensive. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 11

What is an interference engine?

Question 12

What is meant by the term, valve overlap?

Question 13

Technician A says a new or rebuilt engine should have the idle maintained above 1500 rpm for at least 20 minutes to insure proper lubrication and break in. Technician B says long periods of idle are hard on the camshaft. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 14

Pressures on a lifter can reach 100,000 psi.

Question 15

Lifters are being discussed. Technician A says there is only 0.0002" of clearance between the plunger and lifter body. Technician B says dirt particles in an engine are generally larger than 0.0002". Who is right?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 16

Two factors of cam lobe profile are called lift and length.

Question 17

Technician A says camshaft end thrust on some engines is controlled by the distributor. Technician B says timing can change if camshaft end thrust is not controlled. Who is right?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 18

Another term for mechanical lifter is tappet.

Question 19

Timing belt sprockets should be cleaned with a petroleum-based solvent.

Question 20

All of the following are timing components EXCEPT _____.

A) chain
B) belt
C) tensioner
D) lifter