Saturday 6th June 1908
American Charles Yale Knight obtained a British patent for his internal-combustion engine that used sleeve valves instead of the more common poppet-valve construction. In September the same year Daimler announced that these so-called ‘Silent Knight’ engines would be installed in some of its 1909 models. To combat criticism from its competitors, Daimler had the RAC (Royal Automobile Club) carry out their own independent tests on the Daimler-Knight. RAC engineers took two Knight engines and ran them under full load for 132 hours nonstop. The same engines were then installed in a touring car and driven for 2,000 miles (3,200 km) on the Brooklands race track, after which they were removed and again run on the bench for 5 hours. RAC engineers reported that, when the engines were dismantled, there was no perceptible wear, the cylinders and pistons were clean, and the valves showed no signs of wear either. The RAC was so impressed that it awarded Daimler the 1909 Dewar Trophy. The RAC reports caused Daimler’s share price to rise, £0.85 to £18.75, and the company’s competitors to fear that the poppet-valve engine would soon be obsolete. W O Bentley was of the opinion that the Daimler-Knight engine performed as well as the comparable Rolls-Royce power plant. The Knight engine (improved significantly by Daimler’s engineers) attracted the attention of the European automobile manufacturers. Daimler bought rights from Knight “for England and the colonies” and shared ownership of the European rights, in which it took 60%, with Minerva of Belgium. European rights were purchased from them and used by Panhard et Levassor and Mercedes.