Effects of fuel absorbed in oil film on unburnt hydrocarbon emissions from spark ignition engines. (3rd report. Determination of absorption process of octane or methanol in motor oil by combustion bomb experiments)

Experiments presented in this paper determined the effect of oil films on unburnt hydrocarbon emissions when octane or methanol is used as a fuel. The exhaust gas from a combustion bomb in the presence and absence of oil has been analyzed by gas chromatography. Experiments show that the unburnt fuel concentration increases when motor oil is applied to a surface of the bomb. This result shows that absorption of the fuel occurs in the oil prior to ignition, and dissolved fuel is then desorbed into the burst gas after the completion of combustion. Henry's constant of octane or methanol in the motor oil is also calculated on the basis of the experimental results.