Engine Theory

Question 1

Describe an intake stroke.

Answer 1

Intake valve opens, piston begins to move downward direction 180 degree, air/fuel mixture is drawn in to the combustion chamber.

Question 2

Describe the compression stroke.

Answer 2

Both valves close, piston moves in upward direction to 360 degree, air fuel is compressed.

Question 3

Describe the power stroke.

Answer 3

Both valves remain closed, air fuel mixture is ignited, due to combustion forces the piston travel in a downward direction towards 540 degree

Question 4

Describe the exhaust stroke.

Answer 4

Exhaust valve opens, piston moves in an upward direction to 720 degree, burnt gases are pushed out of the cylinder.

Question 5

Describe cylinder block.

Answer 5

Holds all the other engine parts.

Question 6

Describe the cylinder.

Answer 6

A round hole bored (machined) into the block, it is responsible for guiding piston movement.

Question 7

Describe the piston.

Answer 7

Transfers energy of combustion (burning of air fuel mixture) to the connecting rods.

Question 8

Describe the connecting rods.

Answer 8

Links the piston to the crankshaft and transfers power from the piston to the crankshaft.

Question 9

Describe the crankshaft.

Answer 9

Changes the reciprocating (up and down) motion of the piston and connecting rod to useful rotary (spinning) motion.

Question 10

Describe the combustion cylinder.

Answer 10

Is a small cavity in the cylinder head in which the burning of the air fuel mixture occurs. It is located between the top of the cylinder and the bottom of the cylinder head.

Question 11

Describe the valves.

Answer 11

Open and close to control the flow of the air fuel mixture into the combustion chamber and the flow of the exhaust out of the combustion chamber.

Question 12

Describe the camshaft

Answer 12

Controls the opening of the valves.

Question 13

Describe the valve springs.

Answer 13

Keeps the valves closed when they do not need to be open.

Question 14

Describe the rocker arms.

Answer 14

Transfers camshaft action to the valves.

Question 15

Describe the lifters.

Answer 15

Ride on the camshaft and transfer motion to the other part of the valve train.

Question 16

Describe the flywheel.

Answer 16

Helps keep the crankshaft turning smoothly.

Question 17

Describe the inline block engine configuration.

Answer 17

Cylinders are arranged in a straight line. Can be mounted transversely or longitudinally.

Question 18

What cylinder designs do Inline block engine configurations come in?

Answer 18

4,5,6 and 8 cylinder designs

Question 19

Describe the v-block engine configuration.

Answer 19

Cylinders are arranged in a V configuration. They can be mounted transversely or longitudinally.

Question 20

What cylinder design do the V-block engine configuration come in?

Answer 20

2 (motorcycle), 4, 6, 8, 10, 12, and 16 cylinder configurations

Question 21

The internal combustion engine is a device which…

Answer 21

Transforms the burning of air and fuel into mechanical energy.

Question 22

What are the two types of internal combustion engines?

Answer 22

Spark ignition gasoline engine, and the compression ignition Diesel engine.

Question 23

What are the four stroke cycles of an engine?

Answer 23

Intake stroke, compression Stroke, power stroke, and exhaust stroke.

Question 24

Describe a supercharger.

Answer 24

Is an air compressor that increases the pressure of density of air supplied to an engine. This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing power.

Question 25

Describe a turbocharger.

Answer 25

It’s a gas compressor used to force air into an engine. It increases the amount of air entering the engine to create more power. Turbocharger has the compressor charged by a turbine.

Question 26

What is the abbreviation for carbon monoxide?

Answer 26

CO

Question 27

What is the abbreviation for oxides of nitrogen?

Answer 27

NOX

Question 28

What is the abbreviation for hydrocarbons?

Answer 28

HC

Question 29

Definition of carbon monoxide.

Answer 29

Is an extremely toxic omission that results from the release of partially Burnt fuel. It is due to the incomplete combustion of a petroleum based fuel. It is a odourless, tasteless, and colourless, but deadly gas. It can cause headaches nausea breathing problems and even death if inhaled.

Question 30

Definition of particulates.

Answer 30

Are the solid particles of soot and fuel additives that blow out of a car’s tail pipe.

Question 31

Definition of oxides of nitrogen.

Answer 31

Are emissions produced by extremely high temperatures during combustion. These vehicle emissions produce the dirty brown colour in smog.

Question 32

Definition of hydrocarbons.

Answer 32

Results from the release of unburned fuel into the atmosphere. These vehicle emissions can be caused by incomplete combustion or fuel evaporation.

Question 33

What is a plastigage used for?

Answer 33

Used for measuring bearing clearances

Question 34

What is a straight edge and feel gauge used for?

Answer 34

Used for checking cylinder head or block for warpage.

Question 35

What is a micrometer and dial bore gage used for?

Answer 35

Used for measuring the cylinders for taper and out of round.