THE PETROL ENGINE A mixture of 1. and air burns in 2. → spark 3. → mechanical power
Four strokes: •4. stroke → piston down → intake 5. opens → mixture in the cylinder • compression stroke → piston 6. → compresses mixture • power stroke → 7. ignites compressed mixture → burning 8. expand → piston down • exhaust stroke → 9. up → exhaust valve opens → burnt gases leave the cylinder through 10. system
5. Watch the video and complete the sentences.
1. In a four-stroke engine, the piston goes up and down . 2. In the , the intake valve opens, and the piston moves down from the top dead centre. 3. In the compression stroke, the mixture temperature and pressure become high, and it is ignited by the . 4. In the compression stroke, the occurs. 5. In the power stroke, the piston from the top dead centre to the bottom dead centre. 6. In the exhaust stroke, the exhaust valve opens, and the pushes out the burnt gases. 7. We get complete combustion at the two of the crank. 8. The piston goes four times.
6. Complete the table with the missing information.