Home » Textbooks » Thermal Engineering » Two stroke cycle petrol engine operation description

Two stroke cycle petrol engine operation description

  • Description about operation of two stroke cycle engine in diagram and important points with p-v diagram in simple way.
  • Complete the cycle with two strokes only
  • Ports are used to bring the fuel in to the engine cylinder and exhaust gases are brought into outside from engine cylinder to outside
  • Operation of two stroke cycle petrol engine as shown in the bellow images

two-stroke-cycle-phase-1



  • As show in the image (Phase-1) the piston head move upwards then valve is open in the crank chamber and proportion of air and fuel mixture enter into the crank chamber
  • Already existing air fuel mixture in the cylinder chamber is going to compress as shown in the image (phase-2)

two-stroke-cycle-phase-2

  • At the end of the first stroke piston head move top dead centre then air fuel mixture in the cylinder chamber is compressed and air fuel mixture coming into the crank chamber is stop, valve is closed as shown in the image (phase-2)
  • In this stroke exhaust port and transfer pots are closed
  • After air fuel compression spark plug produce the spark to ignite the air fuel mixture and burning takes place in the cylinder chamber, produce the hot gases
  • The piston head moves downward due the expansion of the hot gases, this is second stroke and it is also called working stroke as shown in the image bellow (phase-3)

two-stroke-cycle-phase-3



  • In the second stroke piston moves downwards then air fuel mixture in the crank chamber is compressed and it is enter into the cylinder chamber through transfer port
  • Transfer port and exhaust ports are open in this stroke
  • Compressed air fuel mixture enter into the cylinder chamber from crank chamber though transfer port and at the piston head mixture deflected upwards by the hump provided on the piston head
  • Air fuel mixture enter into the cylinder chamber is helps the removal of exhausted gases in the cylinder chamber to outside through exhaust port
  • The cycle is completed by the two strokes and again repeat the operation to complete the cycle with same procedure as described above steps
  • In case of exhaust gases do not leave the cylinder, the air fuel mixture gets weak and the efficiency of the engine will decrease

Two stroke cycle engine p-v diagram

p-v-diagram-two-stroke

Related Posts Plugin for WordPress, Blogger...

Leave a Reply

Your email address will not be published. Required fields are marked *