Harry Ricardo

A classic piece of writing in its time, and contains much quite detailed thought and analysis, but time has marched on. "High Speed" in this case means 3000rpm. It contains a good account of the development of large four stroke engines between WW1 and WW2 but most data is firmly in the 1915 - 1930 era. The material is evenly split between spark ignition and compression ignition with useful chapters on supercharging, two strokes, and sleeve valve engines. Since sleeve valve engines have all but disappeared this latter chapter was an education for me. they seems to run better and be less prone to detonation than their poppet valve counterparts, so I am left wondering why they disappeared. The testing of alternative fuels, alternative to the 50 octane available (!) is interesting as it gives data for methanol, ethanol, toluene, benzol and others. It was significantly later that the "octane" rating was agreed. Good background and history, but little immediate help in today's world