Engines
Internal combustion engine
connecting rod [N-COUNT] A connecting rod is a piece that connects the piston to the crankshaft.
crankcase [N-COUNT] A crankcase is the bottom part of the engine surrounding the crankshaft.
crankshaft [N-COUNT] A crankshaft is the main shaft in the engine that is moved by the connecting rods.
cylinder [N-COUNT] A cylinder is a round hole in the cylinder block that contains a piston.
engine block [N-COUNT] An engine block is the main part of the engine to which other parts are attached.
head [N-COUNT] A head is the part attached to the top of the engine that covers the tops of the cylinders, holds the spark plugs, and often contains valves.
piston [N-COUNT] A piston is a cylindrical plug that moves up and down in the cylinder during combustion.
piston ring [N-COUNT] A piston ring is a metal ring that fills the space between a piston and the cylinder wall.
spark plug [N-COUNT] A spark plug is a device that uses electricity to create a spark to ignite the fuel.
sump [N-COUNT] A sump is a reservoir that stores oil in the engine.
valve [N-COUNT] A valve is a device that control the flow of fluid by opening and closing.
Diesel vs. gasoline
biodiesel [N-UNCOUNT] Biodiesel is a form of liquid fuel made from vegetable oils and/or animal fats.
clean diesel [N-UNCOUNT] Clean diesel is a more refined form of diesel that emits fewer pollutants than regular diesel.
combustion chamber [N-COUNT] A combustion chamber is a place within an engine where fuel is compressed and ignited.
compression ratio [N-UNCOUNT] A compression ratio is the ratio of a combustion chamber’s largest and smallest volume as measured by the piston in the lowest and highest positions.
diesel [N-UNCOUNT] Diesel is a liquid fuel made from petroleum that is heavier, cheaper, and less refined than gasoline.
durable [ADJ] If something is durable, it is can withstand a lot of use and stress.
fuel injection pump [N-COUNT] A fuel injection pump is a device that forces fuel into the combustion chamber
gasoline [N-UNCOUNT] Gasoline is a liquid fuel made from petroleum that is used in most cars.
glow plug [N-COUNT] A glow plug is a wire in some diesel engines that heats the air in the combustion chamber when the engine is cold.
heat up [V-T] To heat something up is to make it get hotter.
maintenance [N-UNCOUNT] Maintenance is the act of making regular adjustments and repairs to keep an engine working properly.
precombustion chamber [N-COUNT] A precombustion chamber is a small contained space where air is warmed before entering the main combustion chamber.
run on [V-PHRASAL] To run on something is to be powered by that source of fuel.
Two-stroke engine
compress [N-UNCOUNT] To compress is to make the volume of something smaller.
cycle [N-UNCOUNT] A cycle is the motion of the piston from one position to the other and back to the initial position.
exhaust [N-UNCOUNT] Exhaust is the gas that is given off when fuel is burned.
fire [V-I] To fire is to create a spark which ignites the fuel mixture in an engine.
fuel [N-UNCOUNT] Fuel is the liquid substance that an engine burns to create mechanical energy.
fuel-to-oil ratio [N-COUNT] The fuel-to-oil ratio is proportion of oil to fuel used in a two-stroke engine.
inlet [N-COUNT] An inlet is where air, fuel, and oil enter the combustion chamber.
mix [V-T or I] To mix is to combine two or more things.
revolution [N-COUNT] A revolution is one complete turn of the crankshaft.
two-stroke engine [N-COUNT] A two-stroke engine is a type of internal combustion engine that completes its cycle when the crankshaft makes one revolution.
two-stroke oil [N-UNCOUNT] Two-stroke oil is a special oil added to the fuel of a two-stroke engine to lubricate it.
Four-stroke engine
compression stroke [N-COUNT] A compression stroke is the stage in the four-stroke cycle in which a piston moves to the top of the cylinder to compress the mixture of fuel and air.
cylinder head [N-COUNT] A cylinder head is the part of a four-stroke engine that houses the valves and often contains passages for transferring excess heat away from the engine.
exhaust stroke [N-COUNT] An exhaust stroke is the stage in the four-stroke cycle in which the piston returns to the top of the cylinder to force the mixture of fuel and air out through the open exhaust valve.
exhaust valve [N-COUNT] An exhaust valve is the part of a four-stroke engine where the spent mixture of fuel and air is released from the cylinder.
four-stroke engine [N-COUNT] A four-stroke engine is a type of engine commonly used in cars, aircraft and other machinery. It cycles through four stages, or strokes, called intake, compression, power and exhaust.
head gasket [N- COUNT] A head gasket is a ring that seals the cylinder head to maintain the proper pressure inside the cylinder and prevent substances from leaking in or out.
ignite [V-T] To ignite something is to cause it to burn or catch fire.
intake stroke [N-COUNT] An intake stroke is the stage in the four-stroke cycle in which a piston moves to the bottom of the cylinder and makes room for fuel and air to enter the cylinder. Fuel and air are forced in through the intake valve.
intake valve [N-COUNT] An intake valve is the part of a four-stroke engine where fuel and air enter the cylinder before being compressed.
power stroke [N-COUNT] A power stroke is the stage in the four-stroke cycle in which heat ignites the compressed mixture of fuel and air, causing tremendous pressure that forces the piston to the bottom of the cylinder. This stage is the primary source of a machine’s power.
pressure [N-UNCOUNT] Pressure is force that is caused by something pushing against something else.