采用与排放的常规测量方法（通常为排气总管取样）、不同的各缸分别取样测量方法，对492QC发动机怠速时的HC、CO排放及其缸间差异进行了研究．结果表明：试验用发动机各缸的CO排放差异不大，HC的排放差异很大，HC排放最大的为HC排放最小的10倍之多．如能使各缸的HC排放水平都能达到排放浓度最小，则发动机的HC排放可降低为由排气总管测得的HC体积分数的30％左右． The routine and emission measurement methods (usually exhaust manifold sampling), different cylinders were sampled and measured separately, the 492QC engine idling HC, CO emissions and differences between the cylinders were studied. The results show that there is not much difference in CO emission among the cylinders of the engine under test, and there is a great difference in HC emission. The largest HC emission is 10 times of the smallest emission of HC. If HC emissions from each cylinder are to be at a minimum, the HC emissions from the engine can be reduced to about 30% of the HC volume fraction measured by the exhaust manifold.