Ignition of the Gasoline Engine by Injection of Ignition Agents

Some ignition agents such as diesel fuels with high cetane number or ethyl-ether, decompose readily into products that cause spontaneous ignition of the gasoline engine, when they are injected into the combustion chamber. High speed motion pictures of flame using a testing engine with glass window reveal that spontaneous ignition occured at different quarters in the combustion chamber. Results of tests carried out with the CFR engine and another gasoline engine indicated that the injection of such ignition agents extended the use of lean mixtures well beyond the usual lean limit with spark ignition and that knock-free combustion was obtained at the higher compression ratio like 10.3 : 1 even with a fuel of 51 octane number.