Internal Energy: The sum of all energy in a substance, potentialAnd kinetic.

This energy changes constantly in an internalCombustion engine because of the burning andCooling that takes place.

The engine block stores the heat energy of theBurned fuel.

Engine block material:

Cast iron: Provides a stable base that does not distort easily.

Pores to hold oil.

Heavy

Hard and brittle

Engine block material:

Aluminum: High strength to weight ratio

Ease of manufacture

Great heat dissipation

Less resistant to wear

Greater thermal expansion

Thermal conductivity: The ability of a material to transfer heat.

Aluminum is high

Cast Iron is lower

Thermal expansion: Growth in all directions from heat

Dimensional change in a material for one Degree F increase.

Material will recover

Thermal growth: Growth of a material with no change back toIts original size.

Thermal distortion: Asymmetrical expansion due to heat

Bore and seat heat differential

Conduction, convection, and radiation of heat

Air cooled engines:

Components:

Flywheel with fins.

Blower housing

Air guards

Cylinder cooling fins

OilPhase modulated cooling fins Irregular shapes and

Spacing to reduce noise.Ducting: More control of air flow to increase the cooling

Effect. Better warm up.

Plenum: A specific path for incoming or outgoing air.

Hot soak back: When the engine is shut off when hot the heat willVaporize the gas in the carburetor.

Liquid cooled: A more stable cooling system.

Liquid: Water, antifreeze (ethylene glycol)

Passages: Cavities that direct the liquid in the right area.

Pressurized: It increases the boiling point of the liquid.

Radiator: Multi channeled chamber that cools the liquid.

The bottom is cool The top is hot

Pump: Circulates coolant usually with a a fan.

Thermostat: Between the block and the radiator

Opens when a certain temperature is reached andAllows the water to circulate

175-195 degrees F (wax pellet)

Lubrication: The use of a substance, usually a liquid, that reduces Friction.

All surfaces have Asperities, or peaks, with valleys thatHelp hold oil on their surfaces.

Oil characteristics: Qualities that separate different oils.

Viscosity: The ability of an oil to flow at a given temperature.

A low number means it will flow easily.

Assigned by the Society of Automotive Engineers(SAE)

In a multi-viscosity oil, the first number which is Followed by a W indicates its viscosity at 0 degrees F.The second number its viscosity at 212 degrees F.

Polymers make a multi-viscosity oil work.

Oil characteristics:

Service or quality grades:

Designated by the American Petroleum Institute (API)

The first letter indicates the type of fuel used by the engines

S= gasoline engines C=diesel engines

The second letter indicates the level of service, the higher theAlphabetical letter the better the oil. This letter will continue toConstantly change as new engines are developed which requireDifferent oils.

Energy conserving:

The ability of an oil to reduce friction and conserve energy Compared to a index oil.

Lubrication systems: How oil reaches the moving parts of anEngine.

Splash: Uses dippers and slingers to “throw” the oil aroundInside the engine to moving parts.

Pressure filtration: The use of a pump to filter part of the oil andSend it under pressure to certain parts of the Engine.

These systems also use aSlinger to lubricate the otherMoving parts.

Lubrication systems:

Pressure: Uses a pump and oil passages “galleries” machined intoThe engine parts to force oil to them. Oil is filtered first.

Some pumps may operate up to 70 PSI.

High pressure is reduced by a pressure relief valve.

Low oil safety system:

Some engines are equipped with systems that will not let the engine Start or run if low oil levels are present.

Some use a spark device in the oil. If there is enough oil presentIt will not fire and the regular spark plug will fire. If the oil levelIs below the oil spark plug it will fire NOT the regular spark plug.