Ideal thermodynamic cycle
See Through Glass Head on Briggs and Stratton Internal Combustion Engine in Slow Motion and 4K Slow Motion. you can see just how and engine really works and the internal engine combustion process when we use our Phantom to film inside the engine in High Speed
1-2 ISOTHERMAL Heat addition (expansion).
2-3 ISOCHORIC Heat removal (constant volume)
3-4 ISOTHERMAL Heat removal (compression)
4-1 ISOCHORIC Heat addition (constant volume)