EXHAUST GAS HYDROCARBONS-GENESIS AND EXODUS

New evidence is presented that wall quenching is the principal cause of the failure of all the fuel to burn in the combustion chamber. Moreover, it is shown that a significant portion of the quenched hydrocarbons are not exhausted from the engine cylinder. The hydrocarbon concentration of the gases which are exhausted from the chamber varies with time during the exhaust stroke. In addition, some of the quenched hydrocarbons may burn in the exhaust pipe. These findings provided a basis for enumerating several factors which ultimately determine the amount of hydrocarbons which reach the atmosphere.