Chapter 5 Summary Flashcards
A gasoline- fueled engine is
A mechanism designed to transform the chemical energy of burning fuel into mechanical energy.
A gasoline engine is an
Internal combustion engine.
In an internal combustion engine, how is gasoline used?
It is combined with air and burned inside the engine.
The more surface area of gasolinr exposed to the air:
The faster a given amount will burn.
what must happen to gasoline in order
to produce the rapid burning required in an engine?
It must be broken up into tiny droplets and mixed with air.
What is the name of the process of breaking down gasoline into tiny droplets and mixing them with air?
Atomizing
What is the stroke of a piston ?
Its movement in the cylinder from one end of its travel to the other
Four-stroke engines need four strokes to complete the operating cycle:
Intake,compression, power, and exhaust.
How is lubrication of four- stroke engines generally provided?
A splash system or a pump system.
What happens In a two-stroke engine?
The intake, compression, power, and exhaust functions take place during two strokes of the piston.
(True or False)
Two stroke engines are typically smaller and lighter than four-stroke engines of equivalent horsepower?
True
Two-stroke engines receive lubrication as a fuel-oil mixture is passed through the engine, which causes what to happen?
It receives adequate lubrication even when operated at extreme angles.
A gasoline fueled engine changes ______ energy to ____ energy.
A: Chemical, mechanical
(True or False)
In an internal combustion engine, gasoline is combined with air and burned inside the engine.
True
To perform useful work, combustion force must be____?
A: Contained
The four strokes of a four- stroke engine in proper order are:
A: Intake, Compression, power, exhaust.
Each of the following is a function of the intake valve except____.
D: it must get hotter than the exhaust valve to burn off by-products of combustion.
When the atoms that make up molecules of air and fuel are compressed, _____ energy is created.
C: Heat
(True or False)
Because fuel is atomized, the entire air-fuel charge burns at once.
False?
The removal of gases from the cylinder during the exhaust stroke is known as:
B: Scavenging
(True or False)
Valve timing is measured in degrees of crankshaft rotation.
True
The compression ratio must be limited in gasoline spark ignition engines, because:
D: The heat of compression will ignite the air fuel mixture too soon
The time during the four-stroke cycle when both valves are ooen is called____?
B: Overlap
(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.
False
(True or False)
Four-stroke engines do not require periodic oil changes
False
In a two-stroke engine, it takes_____ revolution(s) of the crankshaft to complete an entire two-stroke cycle.
A. One
(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.
True
Each of the following is an advantage of a two-stroke engine except _____.
A. It uses less fuel than a comparable four stroke engine.
Why is gasoline atomized before being burned in an engine.
To produce the rapid burning required in an engine. It causes a sudden release of heat energy.
Why is there a difference in temperature between the intake valve and the exhaust valve?
The intakes do not get as hot as the exhausts. The incoming air-fuel mixture tends to cool the intake valve during operation.
How does compression increase the force of combustion?
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.
what types of engine performance problems are likely to occur if fuel is improperly atomized?
What are some of the characteristics of gasoline that make it an ideal fuel for small internal combustion engines?
Which implements and applications are better suited for the use of a four- stroke engine than a two-stroke engine?
