Abstract
Knocking characteristics of some stock components of gasoline were studied under varying operating conditions by the CFR engine. The antiknock characteristics of fuels, clear or with antiknock compounds, were studied by the incipient knock limited compression ratio, which was detected from the knock characteristic dp/dt traces of the combustion chamber pressure on the cathode ray oscilloscope. Fuels used were catalytically reformed naphtha, cracked naphtha, straight-run light naphtha and some primary reference fuels.
It was shown that the lead responses of reformed naphtha and cracked naphtha were greater at richer mixture strength and at more retarded ignition timing.
It was found that the relationship between the incipient knock limited compression ratio and the lead concentration at any operating conditions at the air-fuel ratio of 14.0 could be expressed by the same type of empirical equations for octane number and lead concentration.
The effect of inlet-mixture temperature was analysed using the knock limited compression density at the end of compression stroke.
Making use of a bled manifold, the effects of volatilities of lead alkyl compounds on its distribution in the front end of fuels were observed.
