Module 4: Internal Combustion Engines

Question 1

mechanical device used to convert the heat energy of fuel produced by combustion into mechanical energy.

Answer 1

internal combustion engine

Question 2

main application of ICE

Answer 2

used as prime movers for mobile and field equipment such as tractors, pumps, sprayers, harvesters and threshers

Question 3

other applications of ICE

Answer 3

• fishing boats to increase fishermen’s mobility
• places where elec motors cannot be used

Question 4

parts of ICE converts reciprocating linear motion into?

Answer 4

rotational motion

Question 5

movement of the piston from TDC to BDC or vice versa

Answer 5

stroke

Question 6

highest position attained by the piston when it goes up

Answer 6

top dead center (TDC)

Question 7

lowest position attained by the piston when it goes down

Answer 7

bottom dead center

Question 8

engine classification based on no. of piston movement needed for a cycle

Answer 8

1) 4-stroke
2) 2-stroke

Question 9

engine classification based on manner of igniting the fuel

Answer 9

1. spark ignition
2. compression ignition

Question 10

in a 4-stroke cycle engine, each stroke corresponds to what?

Answer 10

each corresponds to an event in the cycle

Question 11

in a 2-stroker cycle engine, power and exhaust happens in one stroke and intake and compression happens on the other

true or false

Answer 11

false; power, exhaust, and intake happens in one stroke

Question 12

in a spark-ignition engine, what is used to ignite the compressed air-fuel mixture?

Answer 12

spark plug

Question 13

spark-ignition engine

spark occurrence is timed when

Answer 13

before or at TDC

Question 14

spark-ignition engine

what type of fuel is used

Answer 14

gasoline

Question 15

spark-ignition engine

air and fuel is mixed and metered by the _________ before the intake event

Answer 15

carburetor

Question 16

engine that uses heat of compressed air to ignite the fuel

Answer 16

compression-ignition engine

Question 17

in a compression-ignition engine, air is compressed to a very high degree

true or false

Answer 17

true

Question 18

during intake in a compression-ignition engine, air and fuel is taken in

true or false

Answer 18

false; only air is taken in, fuel is injected before end of compression

Question 19

compression-ignition engine

what type of fuel is used

Answer 19

diesel

Question 20

in a compression-ignition engine, fuel metering is done by?

Answer 20

fuel injection system

Question 21

series of events occurring one after the other in a definite sequence and repeats itself after the last event has occurred.

Answer 21

cycle

Question 22

four events comprising an engine cycle

Answer 22

1. intake
2. compression
3. power
4. exhaust

Question 23

cycle of operation (explain the steps)

Answer 23

air-fuel mixture or air enters combustion chamber —> it is compressed inside —> spark is produced or fuel is injected and the mixture is ignited resulting to a very rapid expansion of the burning mixture —> constitutes the power of the engine —> burned gases are removed —> cycle is repeated

Question 24

basic engine terminology

Answer 24

1. bore
2. stroke
3. piston displacement
4. clearance volume
5. total volume
6. compression ratio

Question 25

engine specifications

Answer 25

1. engine type 2. engine dimensions 3. output 4. capacities 5. auxiliary systems

Question 26

diameter of the cylinder, inches or mm

Answer 26

bore (D)

Question 27

length of travel of the piston from TDC to BDC, inches or mm

Answer 27

stroke (L)

Question 28

volume displace by the piston as it moves from BDC to TDC, cubic inches, cubic mm, or cubic cm

Answer 28

piston displacement

Question 29

volume of the cylinder when the piston is at TDC

Answer 29

clearance volume

Question 30

volume of the cylinder when the piston is at BDC

Answer 30

total volume

Question 31

how do you get the total volume?

Answer 31

add piston displacement and clearance volume

Question 32

ratio of total volume over clearance volume

Answer 32

compression ratio

Question 33

serve as a good source of power to perform diff kinds of farm operations

Answer 33

ICE

Question 34

devices that generate work using the products of combustion as the working fluid rather thanas a heat transfer medium

Answer 34

ICE

Question 35

commonly, diesel engines are used in what type of tractor to perform specific farm operations like in crop establishment processes?

Answer 35

two-wheel tractors

Question 36

a diesel engine is heavier and stronger than a gasoline engine of an equal hp because?

Answer 36

its materials are used to withstand the greater dynamic forces from higher combustion pressures present in the engine

Question 37

higher compression ratio results to greater combustion pressure true or false

Answer 37

true

Question 38

measure of how much the engine compresses the gas in the cylinder

Answer 38

compression ratio

Question 39

lower ignition temp of gasoline will cause ignition at a CR of less than __:1

Answer 39

10

Question 40

in diesel engines, CR ranges from 14:1 to as high as 24:1 true or false

Answer 40

true

Question 41

higher CR of diesel engine is made possible because?

Answer 41

only air is compressed and then fuel is injected