You have been hired by advanced combustion engineering and your boss has asked you to work on a new downsized, boosted gdi engine concept that will be designed to replace an existing 6-cylinder automotive gasoline engine. the existing engine has displaced volume of 500 cm per cylinder, compression ratio of 11.5: 1, port fuel injection, and operates naturally aspirated. based on your knowledge gained from mec 423/523 you propose to downsize the engine to 4 cylinders, keep the cylinder displaced volume the same, and operate unthrottled and globally lean at y = 0.8 with late injection of the fuel to create a stratified mixture in the cylinder. you also propose to use a turbocharger that can the engine to operate at intake pressure of 1.8 bar with exhaust pressure of 1.5 bar. in order to prevent the engine from knocking you also suggest to reduce the compression ratio to 10: 1. based on these changes, you claim that the new engine will operate at higher load compared to the existing one, which will offer higher net indicated efficiency and higher torque than the existing one. your boss is unsure of the success of your proposed design and has asked you to present a detailed comparison between the two engines. you are asked to do the following: 1. sketch the mass fraction burned curves for both engines on the same graph. explain the differences between the two engines in flame initiation (ca0-10%), flame propagation (ca10-90%), and flame termination (ca90-100%) phases. does your proposed design burn faster or slower than the existing engine? 2. will the new engine have higher or lower combustion efficiency than the existing one? explain your answer. 3. will the new engine have higher or lower net indicated efficiency than the existing one? explain your answer. 4. will the new engine have higher or lower brake efficiency than the existing one? explain your answer. 5. will the new engine produce more power than the existing one? make appropriate assumptions and explain your answer. 6. how will the co2, co, uhc, and nox emissions compare between the two engines? explain your answer.