Deck 17: Engine Breathing: Intake and Exhaust Systems

Question 1

When a port has been designed for a particular engine, it remains in the computer's memory and can be duplicated using a ____ on future sets of heads.

A) CNC machine
B) flowbench
C) calibrated porting machine
D) Superflow bench

Answer 1

A

Question 2

Hemispherical combustion chambers restrict airflow because of shrouding.

Answer 2

True

Question 3

Modern day engines can have _____ valves per cylinder.

A) two
B) three
C) four
D) all of the above

Answer 3

D

Question 4

Technician A says that when valve lift reaches 25% of the port opening, maximum airflow is achieved. Technician B says the more a spring is compressed to lift a valve, the more pressure it exerts resulting in increased reliability. Who is right?

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

Question 5

Racing engines that operate at speeds above 14,000 rpm often use pneumatic valve closing mechanisms.

Question 6

Technician A says cross-flow heads improve engine breathing. Technician B says cross-flow heads inhibit engine breathing. Who is correct?

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

Question 7

What is the purpose of a catalytic converter?

Question 8

A straight through muffler has short pipes and baffles that cause the exhaust gases to move back and forth as they travel through the muffler.

Question 9

What are the three styles of exhaust systems?

Question 10

As each valve opens and compresses its valve spring, another valve is closing, decreasing pressure as its spring re-extends. This is known as the ____ characteristic.

A) resonance
B) regenerative
C) oscillating
D) frequency

Question 11

Technician A says restrictor plate racing involves blocking off some of the exhaust ports. Technician B says manifolds that flow air only can have sharper bends than those that flow air and fuel. Who is correct?

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

Question 12

Technician A says high rpm performance can mean poor low rpm performance. Technician B says purchasing just a high performance manifold without matching components will probably hurt performance. Who is correct?

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

Question 13

Exhaust manifolds are often made of ____ because of its ability to tolerate fast, severe temperature changes.

A) mild steel
B) aluminum
C) cast iron
D) stainless steel

Question 14

What is plenum?

Question 15

Cylinder heads are being discussed. Technician A says porting is when the size of a passageway is altered. Technician B says polishing smoothes the surface of the port. Who is right?

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

Question 16

Newer engines with port fuel injection (PFI) require intake manifold heating.

Question 17

Headers are exhaust manifolds made of steel tubing.

Question 18

What is the formula for the CFM requirement at 100% volumetric efficiency? Give an example.

Question 19

What is the meaning of the term, red line?

Question 20

Technician A says press bending reduces the diameter of tubing. Technician B says a mandrel bender prevents changes in a tube's diameter during the bend. Who is correct?

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