An engine operates on an air-standard Otto cycle. The pressure and temperature at the beginning of the compression stroke are 110kPa and 40 deg. Celsius, respectively. The temperature at the end of the compression stroke is 500 deg. Celsius. If the heat added during the heat addition process is 1500 kJ/kg, calculate the maximum pressure that the walls must withstand. Also find the cycle efficiency. Assume temperature independant properties for air. For ideal gas, Pv/T = constant.