Internal Energy: The sum of all energy in a substance, potential And kinetic. This energy changes constantly in an internal Combustion engine because of the burning and Cooling that takes place. The engine block stores the heat energy of the Burned 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 to Its 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 Oil Phase modulated cooling finsIrregular 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 will Vaporize 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 and Allows the water to circulate degrees F (wax pellet)

Lubrication: The use of a substance, usually a liquid, that reduces Friction. All surfaces have Asperities, or peaks, with valleys that Help 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 the Alphabetical letter the better the oil. This letter will continue to Constantly change as new engines are developed which require Different 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 an Engine. Splash:Uses dippers and slingers to “throw” the oil around Inside the engine to moving parts. Pressure filtration: The use of a pump to filter part of the oil and Send it under pressure to certain parts of the Engine. These systems also use a Slinger to lubricate the other Moving parts.

Lubrication systems: Pressure: Uses a pump and oil passages “galleries” machined into The 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 present It will not fire and the regular spark plug will fire. If the oil level Is below the oil spark plug it will fire NOT the regular spark plug.