Mode of Formation of Lead Deposits in Gasoline Engines 530245
DEVELOPMENT of an effective technique for the study of the formation of combustion chamber deposits is described in this paper. The method is based on the extraction of samples from the end gas of an engine cylinder by means of an electromagnetic sampling valve, arranged to open over a narrow range of crank angles.
Lead compounds in the sample are deposited on a nickel foil placed in the body of the valve. Subsequently, they are identified by X-ray diffraction or, if necessary, by analytical chemical methods. The samples provide data on the mechanism of scavenging, particularly on the various steps occurring between the first breakdown of tetraethyl lead and the formation of the final products.
The technique also provides data on the exact mechanism of the antiknock action of tel.