,Whats this?,Its a heart.,Whats that?,Beijing is the heart of our country.,Its a map of China.,What is the heart of a car?,Which part is known as the heart of a car?,Engine,The Four-Stroke Cycle of Engine Operation,无锡公益职业学校 陶曙婷,exhaust valve,intake valve,进气阀,排气阀,piston,活塞,cylinder,气缸,connecting rod,连杆,crankshaft,曲轴,spark plug,火花塞,intake,进气,压缩,compression,做功,power,排气,exhaust,Intake：,is drawn in,intake valve,open,exhaust valve,closed,air-fuel mixture,piston,goes down,valves,closed,Compression：,piston,goes up,Power：,piston,goes down,spark plug,an electric spark is produced,firing,Exhaust:,intake valve,closed,exhaust valve,open,piston,goes up,waste gases,are pushed out,Intake：,a. The intake valve ,b. The goes down.,c. The piston draws the air-fuel mixture into the ,opens.,piston,cylinder.,Compression：,a. The closes.,b. Crankshaft pushes the piston again.,c. The mixture is upward into the combustion chamber.,valves,up,compressed,Power：,a. An electric is produced.,b. The spark ignites the mixture.,c. The piston goes ,spark,air-fuel,down.,Exhaust:,a. The valve opens.,b. The waste are pushed out of the engine.,exhaust,gases,intake,compression,exhaust,power,Identify the differences between the gasoline engine and the diesel engine,a. Only is drawn into the cylinder.,b. fuel oil is injected into the cylinder at the end of the compression stroke.,air,Diesel,