Calculate the mean piston speed, bmep, and specific power of: (a) the spark-ignition engines in Figs. 1.11 and 1.13 at their maximum rated power and torque; and (b) the mean piston speed, bmep, and specific power of the diesel engines in Figs. 1.31 and 1.32 at their maximum rated power and torque. Briefly explain any significant differences between these two types of engine.