Engine Physics

Front 1

Matter

Back 1

°Occupies space and has weight(mass)

°composed of atoms

Front 2

Solid (Characteristic of Matter)

Back 2

°3 dimensions

°Resistant to change in shape

°Does not naturally conform to shape of container

*Heated solids turn into liquids

Front 3

Liquid (Characteristic of matter)

Back 3

°No clearly defined shape.

°FILLS BOTTOM AND SHAPE OF CONTAINER

° Can be atomized(liquid drops suspended in air).

*Flammable liquids must be vaporized(turned into a gas) before they will burn

Front 4

Gas (Characteristic of Matter)

Back 4

°No clearly defined shape.

*EXPANDS TO FILL THE SHAPE OF CONTAINER

° Highly compressible

Front 5

Plasma (Characteristic of Matter)

Back 5

°No clearly defined shape

°Does not fill a container like a gas or water(amorphous).

*SUPER HEATED GAS

*Cooled plasma changes form to a gas.

Front 6

Air

Back 6

°78% Nitrogen

°21% Oxygen

°1% inert (not able to move) gases

Front 7

Air pressure

Back 7

°Mean Sea Level Pressure (MSLP) is normal,everyday atmospheric pressure=14.7psi

°⬇when altitude⬆

°pressure differences between two points results in air movement

°Can move matter ex:weather.

°AN ENGINE'S INTAKE EVENT

Front 8

Air Density

Back 8

Front 9

Boyle's Law

Back 9

A trapped gas doubles its pressure each time it's volume (space) is halved (compressed,lessened)

Front 10

Power

Back 10

°Is the production of EFFORT, WORK OR FORCE

*FORMULA: Power=Amount of work÷ period of time

Front 11

Motion

Back 11

Change of position over time

Front 12

Velocity

Back 12

°INDICATES SPEED OR DESTINATION of an object's movement

°constant velocity is the speed of an object from point A to point B

Front 13

Acceleration

Back 13

°rate of velocity over time.

*How fast you can reach a certain SPEED (ex: Mario Kart)

Front 14

Mass

Back 14

°Resistance of an object to acceleration

*considered weight by motorcycle standards

Front 15

Inertia

Back 15

Resistance to change in motion or direction

Front 16

Law of Inertia

Back 16

A body in motion wants to stay in motion ( short version)

Front 17

Momentum

Back 17

°The ENERGY WITHIN a moving object

*FORMULA: =mass x velocity

Or =weight x speed

Front 18

Energy

Back 18

°is the ABILITY TO DO WORK

*Thermal= light and warmth emitted by 🔥

*Electrical= spinning an electric motor with power

*Gravitational= dropping an object and watching it fall

*Magnetic= push two + magnets together and fuel the resistance

Front 19

Newton's Law

Back 19

°Energy cannot be CREATED OR DESTROYED

° Can be converted or changed from one form to another

*conversion is not 100% efficient

➡EXAMPLE: Drop a ball and it will not bounce up to the same level

Front 20

Potential Energy

Back 20

°latent or NOT CONVERTED FROM ONE FORM TO ANOTHER

➡EXAMPLE: Holding ball in the air

Front 21

Kinetic Energy

Back 21

°energy required to create movement is stored in a moving object

Front 22

Active energy

Back 22

°energy that has been CONVERTED FROM ONE FORM TO ANOTHER

*EXAMPLE: Energy converted to light

Front 23

Force

Back 23

°The amount of PRESSURE used to create work (weight, pressure, voltage)

°Brake Mean Effective Pressure (BMEP)...indicates the average pressure of all power STROKES

➡FORMULA: 2-stroke BMEP = 75.4 psi × Torque (ft - lb.) ÷ Displacement (CI)

➡ FORMULA: 4-stroke BMEP = 150.8 psi × Torque (ft.- lb.) ÷ Displacement (CI)

Front 24

Work

Back 24

°The application of FORCE TO MOVE AN OBJECT

➡FORMULA: force × distance

**EXAMPLE: 50 lb. pushing on 1 ft. long lever = 50 ft.- lb. torque

** movement of the piston in a cylinder is work

Front 25

Leverage

Back 25

°Ability of a pivoting bar to use distance to gain mechanical advantage.

Front 26

Leverage

Back 26

°ability of a pivoting bar to use distance to gain mechanical advantage

Front 27

Torque

Back 27

°ability to create TWISTING OR ROTATIONAL WORK

➡EXAMPLE: combustion FORCE applied to crankshaft leverage

Front 28

Horsepower

Back 28

°Is the rate at which work is performed

➡FORMULA: (force×distance) ÷ time = power

*HORSEPOWER RESULTS FROM TORQUE (COMBUSTION FORCE) AND RPM (COMBUSTION FREQUENCY)

Front 29

Oxidation (Combustion)

Back 29

°COMBINING OXYGEN TO ANOTHER MATERIAL

Front 30

Internal Combustion (Gasoline Engine)

Back 30

°Compresses air and fuel then used a spark to initiate combustion

Front 31

Internal Combustion ( Deisel Engine)

Back 31

° Compresse air and fuel until the temperature increases to the point of combustion (Boyle's law)

Front 32

External Combustion

Back 32

°combustion occurs outside the engine

➡EXAMPLE: steam engine

Front 33

1st stage of COMBUSTION

Back 33

COMBUSTION LAG is the time it takes after ignition for combustion to reach peak pressure (low pressure to peak pressure)

Front 34

2nd stage of COMBUSTION

Back 34

°ACTIVE COMBUSTION is the working pressure.

Front 35

3rd stage of COMBUSTION

Back 35

°POST-COMBUSTION activity.

°no power production

°The piston continues moving due to crankshaft momentum.

Front 36

Abnormal Combustion (Pre-ignition)

Back 36

°Is an untimed burn event (valves) with normal combustion speeds.

°Occurs BEFORE normal ignition.

* Will not cause a ping or knock.

**Caused by hot spots in the cylinder such as too hot of a SPARK PLUG, PROTRUDING GASKETS, METAL BURRS,AND CARBON DEPOSITS HEATED from previous combustion cycles.

Front 37

Abnormal Combustion (Detonation)

Back 37

°Untimed explosive event with rapid combustion speeds.

*usually happens just after spark ignition

*Usually happens just after spark ignition

°Can be caused by POOR QUALITY FUEL, TOO LOW OCTANE,TOO HIGH OF COMPTESSION RATIOS,HIGH ENGINE LOAD, PRE-IGNITION AND POOR STATE OF TUNE.

Front 38

result of Combustion (physical)

Back 38

°a low thumping sound

°normal pressures may peak over 1000 PSI

°normal temperatures can reach 4000°F (1/3=exhaust,1/3=cooled, 1/3=heat nitrous)

Front 39

Result of Combustion (Chemical)

Back 39

➡carbon monoxide CO is a colorless, odorless, and lethal gas

°partially burned fuel

➡hydrocarbons HC are chains of multiple hydrogen and carbon atoms.

°unburned fuel

*lean mixtures,lean misfires, and low compression can cause high HCs.

Front 40

Result of Combustion (Chemical)

Back 40

➡✅Carbon Dioxide CO2 is the ideal product of HC combustion where two oxygen molecules bind to a carbon molecule and split off from the hydrocarbon chain

°result of complete combustion

Front 41

Result of Combustion (Chemical)

Back 41

➡⚠Oxides of nitrogen NO× or Acid ☔ rain

°NO× is toxic to animals and plants in higher levels

*in low doses NO× is safe for our environment and acts as a fertilizer for plants

*High combustion temperatures cause nitrogen to bond to two or three oxygen molecules

Front 42

Result of Combustion (Chemical)

Back 42

➡✅ water H2O is an ideal by-product of Combustion where the hydrogen molecules bind to oxygen

Front 43

Emissions Standards (CAA) Clean Air Act

Back 43

°1970 Clean Air Act (CAA) was created by Congress to regulate the emission of airborne pollutants.

Front 44

Emission Standards (EPA) Environmental Protection Agency

Back 44

°1970 ENVIRONMENTAL PROTECTION AGENCY (EPA) established to protect the environment and human health and govern the CAA.

*the Environmental Protection Agency (EPA) regulates motorcycle emissions from new Original Equipment Manufacturers (OEMs)

*Exhaust emissions of CO,HC,NO× and particulate matter.

Front 45

Department of Transportation (DOT)

Back 45

°responsible for safe,secure, and quick transportation to support our nation's growth.

* established the National Highway Traffic Safety Administration (NHTSA) to govern safety related items on new automobiles and motorcycles

Front 46

Emission Controls

Back 46

➡CHARCOAL CANISTERS or carbon containers are used to trap fuel which has evaporated from the fuel system or if the fuel tank is overfilled.

*California Air Resource Board (CARB) required emissions item

➡AIR INJECTION allows air to be introduced to exhaust gases.

➡CATALYTIC CONVERTER converts toxic gases to safer gases through oxidation.

*Rich mixtures can cause temperatures to rise and can clog and damage CATALYTIC converters

Front 47

Volumetric Efficiency (Engine)

Back 47

°HOW FULL THE CYLINDER GETS.

*Affected by:

➡Valve timing

➡Intake and exhaust tuning

➡Intake Velocity

➡Naturally aspirated

➡Supercharging or turbocharging can increase volumetric efficency over ambient pressures

Front 48

Combustion efficiency (engine)

Back 48

°HOW COMPLETELY THE CYLINDERS CONTENTS BURN.

Affected by:

➡Combustion chamber design,intake velocity.

➡Anything that affects mixture

Front 49

Thermal efficency (Engine)

Back 49

°HOW MUCH OF COMBUSTION'S HEAT ENDS UP PUSHING ON THE PISTON.

*Heat Distribution

➡30-35% pushes piston

➡30-35% leaves with exhaust gases

➡30-35% radiated away

Front 50

Stroke efficiency (engine)

Back 50

°HOW FAR DOWN THW COMBUSTION STROKE THE PISTON IS MOVED BY THE COMBUSTION PRESSURE

Affected by:

➡ignition timing= when spark plug sparks

➡rod/stroke ratio

Front 51

Mechanical efficiency

Back 51

°HOW MUCH POWER IS LOST TO FRICTION, PARTS FLEX, AND OTHER ENERGY ABSORBING FACTORS, SUCH AS ALTERNATOR DRAG.

Affected by:

➡number of cylinders, number of bearings

➡fit of parts

➡Rigidity of parts