Chapter 6. Summary

Question 1

What component keeps all engine parts in alignment?

Answer 1

The engine block

Question 2

what materials are usually used to make engine blocks

Answer 2

casted iron or an aluminum alloy.

Question 3

The engine block consists of two sections:

Answer 3

The cylinder block
and the crankcase.

Question 4

What is the portion of the engine block that contains the cylinder bore?

Answer 4

The cylinder block

Question 5

What portion of the enginr block contains the crankshaft?

Answer 5

The crank case

Question 6

Which part is the major rotating part of the engine?

Answer 6

The Crankshaft

Question 7

What is the straight line driving member of the engine?

Answer 7

The piston

Question 8

what is the purpose of the piston?

Answer 8

To provide a seal between the combustion chamber and the crankcase.

Question 9

How does the piston provide a seal between the combustion chamber and the crankcase

Answer 9

by grooves being cut into the piston near the top and piston rings being i stalled on the piston.

Question 10

What would happen to the engine without piston rings?

Answer 10

The piston could not compress the fuel charge properly, and burning gases would leak out between the sides of the pisto and the cylunder wall.

Question 11

How many piston rings do most pistons use?

Answer 11

Three

Question 12

If a piston uses three rings; what two ring types do they usually consist of?

Answer 12

The upper two = compression rings.
The lower ring = an oil control ring.

Question 13

What secures the piston to the connecting rod?

Answer 13

The piston pin

Question 14

what attaches the piston to the crankshaft?

Answer 14

The connecting rod

Question 15

How does the connecting rod attach the piston to the crankshaft?

Answer 15

The upper end has a hole that the piston pin is passed through.

The lower end has a large bearing that fits around the crankshaft journal.

Question 16

What has to occur during normal engine operation?

Answer 16

A fresh air-fuel mixture must be admitted to the engine and once its burned , the waste products have to be exhausted.

Question 17

How is the process of admitting a fresh air-fuel mixture into an engine then exhausting the waste products carried out?

Answer 17

By using ports that are alernately covered and exposed by the piston
( two-stroke cycle design)
or by using poppet valves to open and close the port openings ( four-stroke cycle design).

Question 18

What is the purpose of a camshaft in four-stroke engines?

Answer 18

To open the valves the right amount at the right time.

Question 19

What does the valve train consist of?

Answer 19

All of the components that work together to transform the rotation of the crankshaft into the opening and closing of the valves.

Question 20

During the non power strokes, what keeps the crankshaft spinning and smoothes engine operation?

Answer 20

The inertia of the heavy flywheel

Question 21

What do all small gasoline engines have

Answer 21

some provision for spinning the crankshaft during engine starting.

Question 22

What are the two things that can be used as the provision for spinning the crankshaft during engine starting?

Answer 22

A recoil rope starter assembly or an electric starter

Question 23

what do some small engines have to make hand cranking easier?

Answer 23

an automatic compression release mechanism on the camshaft

Question 24

What does an automatic compression release mechanism on the camshaft do that makes hand cranking easier?

Answer 24

It lifts the exhaust valve slightly during cranking and releases part ofbthe compression pressure.

Question 25

The two main sections of an engine block are the

Answer 25

A: Cylinder block and crankcase

Question 26

Aluminum cylinder blocks sometimes cast around a(n)_______ sleeve

Answer 26

B: Steel

Question 27

[True or False] The crankshaft converts the reciprocating motion of the piston into rotary motion

Answer 27

True

Question 28

All of the following are used as crankshaft main bearings, except_____________

Answer 28

C: Lip bearings

Question 29

Each of the following is a type of crankshaft main bearing, except

Answer 29

D: groove

Question 30

[True Or False] The piston provides a seal between the crankcase and the combustion chamber.

Answer 30

True

Question 31

Most pistons use ______ piston rings

Answer 31

C: Three

Question 32

The ridges between the piston grooves are known as the piston__________

Answer 32

B: Lands

Question 33

The piston______ keeps the piston from tipping from side to side

Answer 33

A: Skirt

Question 34

[True or False] Floating piston rings are installed with their end gaps aligned.

Answer 34

False

Question 35

What are placed in grooves in the piston pin bosses to prevent full floating pins from rubbing on the cylinder surface.

Answer 35

B: Snap rings

Question 36

A piston pin may turn in _____

Answer 36

A: Piston bosses B: Bushings C: needle bearings

Question 37

______ Friction bearings are used in the big end of the connecting rod

Answer 37

D: All of the above

Question 38

(True or False) Antifriction bearings use rollers or balls to reduce friction between moving parts.

Answer 38

True

Question 39

In two-stroke engines, the intake and exhaust ports are alternately covered and exposed by the_______ as it moves up and down in the cylinder.

Answer 39

B: Piston

Question 40

Four-stroke engines use_____ valves to open and close port openings.

Answer 40

Poppet?

Question 41

Most small four-stroke engines contain a single camshaft with how many cam lobes for each valve?

Answer 41

A: one

Question 42

(True or False) The crankshaft turns the same speed as the camshaft

Answer 42

False

Question 43

(True or False) Automatic compressionà