Download or read book Theoretical and Experimental Study of Ignition Lag and Engine Knock written by Fritz A. F. Schmidt and published by . This book was released on 1939 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author believes, on the basis of experimental ignition-lag data, that the character of a fuel cannot be stated in terms of a single constant (such as octane or cetane number) but that at least two and generally three constants are required. Thus no correlation between knock ratings can be expected if in one set of tests the charge temperature was varied while in the other the charge pressure was varied. For this reason, he favors knock rating being based on an equation characterizing the ignition lag of the fuel as a function of pressure and temperature of the charge.