Increase in maximum pressures produced by preignition in internal combustion engines S. W. Sparrow naca-tn-14 Aug 1920 With the high compression ratio of the aviation engine, preignition is of frequent occurrence. That extremely high temperatures are a result, is fairly well recognized, but little attention seems to have been given to the pressures that prevail in the cylinder under these conditions. An Adobe Acrobat (PDF) file of the entire report: http://naca.central.cranfield.ac.uk/reports/1920/naca-tn-14.pdf S. W. Sparrow; Increase in maximum pressures produced by preignition in internal combustion engines; naca-tn-14; Aug 1920