Deck 17: Engine Breathing: Intake and Exhaust Systems

Question 1

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

Answer 1

A

Question 2

Headers are exhaust manifolds made of steel tubing.

Answer 2

True

Question 3

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.

Answer 3

False

Question 4

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 5

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 6

What is plenum?

Question 7

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

Question 8

Hemispherical combustion chambers restrict airflow because of shrouding.

Question 9

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 10

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

Question 11

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

Question 12

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

Question 13

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 14

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 15

What are the three styles of exhaust systems?

Question 16

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

Question 17

What is the meaning of the term, red line?

Question 18

Modern day engines can have _____ valves per cylinder.

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

Question 19

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 20

What is the purpose of a catalytic converter?

Question 21

On racing engines, airflow though intake and exhaust passages is tested on a ________ bench.

Question 22

On an engine with a two-barrel intake manifold, if each barrel supplies fuel to four cylinders, what is this manifold design called?

Question 23

Which valve seat angle results in a larger gap between the valve face and seat, 30° or 45° angle?

Question 24

Two technicians are discussing service after a catastrophic engine failure. Technician A says replacement of the intake manifold is recommended by some manufacturers. Technician B says metal parts can be coughed up into the runners of the intake manifold where they can remain even after cleaning. Who is right?

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

Question 25

When higher tension valve springs are used in a high-performance engine, this is inefficient and uses horsepower. True or False?

Question 26

Today's springs are designed with a __________ frequency beyond the normal operating range of the engine.

Question 27

Resonance tuning is based on the __________ Resonance Theory.

Question 28

Which manifold can have tighter bends and bigger runners, port or wet?

Question 29

When a single manifold runner feeds two neighboring cylinders, these are known as _____________ ports.

Question 30

Exhaust manifolds made of steel tubing are called _____________.

Question 31

When intake runners are designed to trap standing waves in the manifold, timing them so they are ready to be breathed when the intake valves open, this is called a _________ manifold.

Question 32

What is installed under valve springs on an aluminum head?

Question 33

What is the name of the type of fuel injection system that injects fuel directly above the intake valve?

Question 34

Which of the following is/are true about titanium valves?

A)They are stronger.
B)They are often replaced after a race.
C)They require less valve closed seat pressure.
D)All of the above
E)A and B only

Question 35

What is the name of the air space in the manifold below a carburetor or throttle body?

Question 36

Multiple coil springs are often used with high lift cams to prevent coil spring _________.

Question 37

When intake and exhaust manifolds are on opposite sides of an in-line engine cylinder head, what is this design called?

Question 38

The amount of intake and exhaust that flows through manifold runners is measured in _________.

Question 39

Technician A says that there is no contact between the center root of the valve locks/keepers and the groove in the valve stem. Technician B says the keepers are clamped tightly to the stem of the valve. Who is right?

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

Question 40

Which of the following are recommended additions when installing a high lift cam?

A)Bronze valve guides
B)Rocker arms with roller tips
C)Higher tension valve springs
D)All of the above
E)None of the above

Question 41

Which of the following is/are true about cylinder head porting?

A)Porting is usually helpful for street car performance.
B)Most factory ports flow 40% more air than can flow through the valve opening.
C)Larger ports can keep air flowing at a higher velocity.
D)With smaller ports at lower rpm, fuel tends to fall out of the air-fuel mixture.
E)All of the above

Question 42

Which of the following can cause an exhaust manifold to run red hot?

A)Excessive engine work load
B)A rich air-fuel mixture
C)Both of the above
D)Neither of the above

Question 43

Stainless steel headers have a shorter life expectancy than cast iron exhaust manifolds. True or False?

Question 44

Technician A says that headers do not improve performance at low rpm unless they are specifically tuned for low rpm use. Technician B says that longer header pipes tend to improve low rpm performance. Who is right?

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

Question 45

Which of the following is/are true about valve springs that have too much pressure when the valve is open?

A)Cam and lifter life are reduced.
B)Valve guide wear increases.
C)Pushrods and rocker arms are caused to flex.
D)All of the above