Begin a preliminary design of a simple, 4-cylinder, naturally aspirated, spark-ignition engine based on an ideal otto cycle. the engine should operate on e30 fuel (assume 30% ethanol, c2h6o and 70% iso-octane, c8h18 on a volume basis, rhoethanol = 790 kg/m3 , rhoiso-octane = 692 kg/m3 ) and less than 5% excess air (to avoid emissions aftertreatment issues). the engine should develop a power of 75 kw under full load at 3500 rpm (remember this is a 4- cylinder engine using a 4-stroke cycle). assume port fuel injection, such that the intake charge contains a fuel/air mixture at 30 °c and 1 bar (state 1). spark is triggered at the end of an isentropic compression stroke (state 2), followed by infinitely fast combustion (state 3). to avoid knock under boosted conditions, your compression ratio cannot be greater than 13: 1. also, consider that most si engines have comparable bore and stroke sizes, but you are free to decide the bore to stroke ratio, β.