Question 1

On the intake stroke, a big gulp of air happens when the piston reaches its maximum velocity at ____° of rod angle.

Accepted Answer

The answer of On the intake stroke, a big gulp...

Question 2

The work efforts needed to move air into and out of the cylinder are called _________ losses.

Accepted Answer

The answer of The work efforts needed to move air...

Question 3

What is the term that describes the camshaft position when the piston is at the top of the intake stroke, the intake valve is beginning to open, and the exhaust valve has not yet finished closing?

Accepted Answer

The answer of What is the term that describes the...

Question 4

A change of 0.001" in valve lash will result in approximately _____° of duration change.

Accepted Answer

The answer of A change of 0.001" in valve lash...

Question 5

Which of the following is/are true regarding lift and duration?

Accepted Answer

A) Increasing duration can cause a rough idle and ruin low-end performance. 
B) Increasing valve lift can cause a rough idle and ruin low-end performance. 
C) Both A and B 
D) Neither A nor B

Question 6

What is the term that describes the part of the power stroke between the time the exhaust valve opens and the piston arrives at BDC?

Accepted Answer

The answer of What is the term that describes the...

Question 7

Technician A says thermal efficiency is the ratio of how effectively an engine converts a fuel's heat energy into usable work. Technician B says the thermal energy of gasoline is about 50,000 BTUs per pound. Who is correct?

Accepted Answer

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

Question 8

What are the two types of hydraulic phasers?

Accepted Answer

The answer of What are the two types of hydraulic...

Question 9

What is the formula for mechanical efficiency?

Accepted Answer

The answer of What is the formula for mechanical efficiency?...

Question 10

What is the name of the one camshaft angle that is measured in camshaft degrees instead of crankshaft degrees?

Accepted Answer

The answer of What is the name of the one...

Question 11

All of the below are factors in camshaft performance EXCEPT _____.

Accepted Answer

A) duration 
B) rate of lift 
C) overlap 
D) valve size

Question 12

Some aftermarket camshaft sprockets for OHC engines are adjustable.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following is/are true when measuring camshaft duration?

Accepted Answer

A) SAE specifications are measured after the valve has lifted 0.060". 
B) High-performance camshafts are usually measured for duration at 0.050" lift. 
C) Both A and B 
D) Neither A nor B

Question 14

What term refers to the intake and exhaust valves being equally open at TDC?

Accepted Answer

A) neutral LCA 
B) advanced cam 
C) retarded cam 
D) split overlap

Question 15

The usable horsepower at the crankshaft is known as ____.

Accepted Answer

The answer of The usable horsepower at the crankshaft is...

Question 16

Technician A says excessive valve lift causes piston-to-valve interference. Technician B says high valve overlap can lead to clearance problems between the valves and pistons. Who is correct?

Accepted Answer

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

Question 17

Which of the following is/are true about a cam with less overlap?

Accepted Answer

A) There will be more pressure in the cylinder at lower rpm. 
B) There will be greater torque at low rpm. 
C) This fits the profile of an RV camshaft. 
D) All of the above 
E) A and B only

Question 18

Which of the following can cause clearance problems between the pistons and valves?

Accepted Answer

A) High valve overlap 
B) Excessive valve lift 
C) Both A and B 
D) Neither A nor B

Question 19

Camshaft timing readings on OHC engines are taken before/after (choose one) the cylinder head is installed.

Accepted Answer

The answer of Camshaft timing readings on OHC engines are...

Question 20

Closing the intake/exhaust [choose one] valve too soon can increase detonation.

Accepted Answer

The answer of Closing the intake/exhaust [choose one] valve too...

Exam 19: Producing Power: Valve Timing, Power and Torque Measurement

On the intake stroke, a big gulp of air happens when the piston reaches its maximum velocity at ____° of rod angle.

The work efforts needed to move air into and out of the cylinder are called _________ losses.

What is the term that describes the camshaft position when the piston is at the top of the intake stroke, the intake valve is beginning to open, and the exhaust valve has not yet finished closing?

A change of 0.001" in valve lash will result in approximately _____° of duration change.

Which of the following is/are true regarding lift and duration?

What is the term that describes the part of the power stroke between the time the exhaust valve opens and the piston arrives at BDC?

Technician A says thermal efficiency is the ratio of how effectively an engine converts a fuel's heat energy into usable work. Technician B says the thermal energy of gasoline is about 50,000 BTUs per pound. Who is correct?

What are the two types of hydraulic phasers?

What is the formula for mechanical efficiency?

What is the name of the one camshaft angle that is measured in camshaft degrees instead of crankshaft degrees?

All of the below are factors in camshaft performance EXCEPT _____.

Some aftermarket camshaft sprockets for OHC engines are adjustable.

Which of the following is/are true when measuring camshaft duration?

What term refers to the intake and exhaust valves being equally open at TDC?

The usable horsepower at the crankshaft is known as ____.

Technician A says excessive valve lift causes piston-to-valve interference. Technician B says high valve overlap can lead to clearance problems between the valves and pistons. Who is correct?

Which of the following is/are true about a cam with less overlap?

Which of the following can cause clearance problems between the pistons and valves?

Camshaft timing readings on OHC engines are taken before/after (choose one) the cylinder head is installed.

Closing the intake/exhaust [choose one] valve too soon can increase detonation.