Can somebody help me about engine analysis?

I've been away from school for about a year now so I may be incorrect, and forgive my bad English.
As you know, from A to B there is no thermodynamic operation.
From B to C it's an adiabatic compression (in a perfect situation) so you get equation no. 1.
From C to D it's an isobaric since the combustion happens instantly so you get equation no. 2.
From D to E it's an adiabatic expansion so back to equation no. 1.

thank you but I need depending on time. I used formul 1 and after formul 2. formul 2 is better than 1 I think.