. Spark-ignition and prechamber diesel engines are both used as engines for passenger cars. They must meet the same exhaust emission requirements. Of great importance are their emission...

. Spark-ignition and prechamber diesel engines are both used as engines for passenger cars. They must meet the same exhaust emission requirements. Of great importance are their emission characteristics when optimized for maximum power at wide-open throttle (WOT) and when optimized at cruise conditions for maximum eEciencv.

 (a) Give typical values for the equivalence ratio for a passenger car spark-ignition engine and a prechamber diesel optimized for maximum power at WOT and 2000 revlmin, and optimized for maximum efficiency at part load (bmep = 300 kPa) and 1500 rev/min. Briefly explain the values you have chosen.

(b) Construct a table indicating whether at these two operating conditions the specific emissions of CO, HC, NO,, and particulates are low (L), medium (M), or high (H) relative to the other load point and to the other engine. Explain your reasoning for each table entry.