Chapter 5 Summary

Question 1

A gasoline- fueled engine is

Answer 1

A mechanism designed to transform the chemical energy of burning fuel into mechanical energy.

Question 2

A gasoline engine is an

Answer 2

Internal combustion engine.

Question 3

In an internal combustion engine, how is gasoline used?

Answer 3

It is combined with air and burned inside the engine.

Question 4

The more surface area of gasolinr exposed to the air:

Answer 4

The faster a given amount will burn.

Question 5

what must happen to gasoline in order
to produce the rapid burning required in an engine?

Answer 5

It must be broken up into tiny droplets and mixed with air.

Question 6

What is the name of the process of breaking down gasoline into tiny droplets and mixing them with air?

Answer 6

Atomizing

Question 7

What is the stroke of a piston ?

Answer 7

Its movement in the cylinder from one end of its travel to the other

Question 8

Four-stroke engines need four strokes to complete the operating cycle:

Answer 8

Intake,compression, power, and exhaust.

Question 9

How is lubrication of four- stroke engines generally provided?

Answer 9

A splash system or a pump system.

Question 10

What happens In a two-stroke engine?

Answer 10

The intake, compression, power, and exhaust functions take place during two strokes of the piston.

Question 11

(True or False)
Two stroke engines are typically smaller and lighter than four-stroke engines of equivalent horsepower?

Answer 11

True

Question 12

Two-stroke engines receive lubrication as a fuel-oil mixture is passed through the engine, which causes what to happen?

Answer 12

It receives adequate lubrication even when operated at extreme angles.

Question 13

A gasoline fueled engine changes ______ energy to ____ energy.

Answer 13

A: Chemical, mechanical

Question 14

(True or False)
In an internal combustion engine, gasoline is combined with air and burned inside the engine.

Answer 14

True

Question 15

To perform useful work, combustion force must be____?

Answer 15

A: Contained

Question 16

The four strokes of a four- stroke engine in proper order are:

Answer 16

A: Intake, Compression, power, exhaust.

Question 17

Each of the following is a function of the intake valve except____.

Answer 17

D: it must get hotter than the exhaust valve to burn off by-products of combustion.

Question 18

When the atoms that make up molecules of air and fuel are compressed, _____ energy is created.

Answer 18

C: Heat

Question 19

(True or False)
Because fuel is atomized, the entire air-fuel charge burns at once.

Answer 19

False?

Question 20

The removal of gases from the cylinder during the exhaust stroke is known as:

Answer 20

B: Scavenging

Question 21

(True or False)
Valve timing is measured in degrees of crankshaft rotation.

Answer 21

True

Question 22

The compression ratio must be limited in gasoline spark ignition engines, because:

Answer 22

D: The heat of compression will ignite the air fuel mixture too soon

Question 23

The time during the four-stroke cycle when both valves are ooen is called____?

Answer 23

B: Overlap

Question 24

(True or False)
All four-stroke engines use an oil pump to distribute the oil contained in the engine’s crankcase to the proper locations throughout the engine.

Answer 24

False

Question 25

(True or False)
Four-stroke engines do not require periodic oil changes

Answer 25

False

Question 26

In a two-stroke engine, it takes_____ revolution(s) of the crankshaft to complete an entire two-stroke cycle.

Answer 26

A. One

Question 27

(True or False)
In a conventional two-stroke engine, a portion of the air-fuel charge flows out through the open exhaust port as exhaust gases are pushed from the cylinder.

Answer 27

True

Question 28

Each of the following is an advantage of a two-stroke engine except _____.

Answer 28

A. It uses less fuel than a comparable four stroke engine.

Question 29

Why is gasoline atomized before being burned in an engine.

Answer 29

To produce the rapid burning required in an engine. It causes a sudden release of heat energy.

Question 30

Why is there a difference in temperature between the intake valve and the exhaust valve?

Answer 30

The intakes do not get as hot as the exhausts. The incoming air-fuel mixture tends to cool the intake valve during operation.

Question 31

How does compression increase the force of combustion?

Answer 31

because tightly packed molecules are highly activated and are striving to move apart. This energy combined with expanding energy of combustion, provides tremendous force against the piston.

Question 32

what types of engine performance problems are likely to occur if fuel is improperly atomized?

Question 33

What are some of the characteristics of gasoline that make it an ideal fuel for small internal combustion engines?

Question 34

Which implements and applications are better suited for the use of a four- stroke engine than a two-stroke engine?