DEPOSIT‐INDUCED RUNAWAY SURFACE PREIGNITION Available to Purchase

OF THE MANY forms of abnormal combustion that occur in petrol engines, runaway preignition is the only one that commonly leads to engine damage. It only occurs in passenger cars under abnormal driving conditions and in truck engines operated at high speed and full load for long periods. According to the Co‐ordinating Research Council runaway preignition is defined as surface ignition which occurs earlier and earlier in the cycle. Research workers L. B. Scott, J. G. Ryan and J. B. Baker, of Shell Oil Co's. Wood River Research Laboratory, presented a paper at the S.A.E. Summer Meeting in June at Atlantic City, when the results of their work on this subject were given.