Poppet Valve System

 

 

The poppet valve has a complex system that is necessary to coordinate when it opens and closes. That system has a cam synchronized with the engine crankshaft, which commands the opening and closing time. To calculate the intake area of the valve when it is open is necessary to know in which crankshaft degree it opens and closes. After it is applied the equations (from Heywood, 1988) for the three different positions.

 

• Position 1:

       

                                                                                                                                        (1)

 

 

• Position 2:

 

                                                                                                                                        (2)

 

 

• Position 3:

                                                                                                                                                                                                                                                                                      (3)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After inserting this equations in Excel, the following graph was obtained,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Analyzing the graph it is possible to see that the intake valve opens at 330º and closes at 590º of the crankshaft. The maximum intake area is                .