This technical article is about the Knight Engine, an early automotive evolution of the internal combustion engine.
Charles Knight, the inventor of the engine, was a printer who published a newspaper for farmers in the US. This was very early in the 20th century and he used a car to get around the community. Being a printer he knew a thing or two about mechanical devices and the car he used had very noisy valves. Like many engineers, he figured he could do a better job and make a quieter engine. The industry is full of people who consider what they bought as inferior and set about doing a better job – Lamborghini and others come to mind!
So with some backing, Knight started to develop a new style engine. It contained two sleeves, one that moved inside the other. The sleeves were the valves that moved the fuel/air mixture and exhaust in and out of the cylinder. The spark plug was centralised in the head – each cylinder head was detachable and because the valves were no longer in the head, the ports could be bigger.
Knight had taken some concepts from early Otto Cycle engines including the concept of a sliding valve. The design was much quieter than the popular poppet valve engine and it needed much less maintenance. This was because the valves moved up and down rather than being hit downwards with a spring to close them, thus there was no noise each time the valves opened and closed. The engine was known as the “Silent Knight”! The downside was that the engine was very expensive to make and it used more oil than other designs.
Because of the expense in manufacturing, none of the US based manufacturers wanted it, so Knight took a unit to the UK and showed it to the British Daimler company. They fitted it to a car and gave it to the Royal Automobile Company (RAC) to test. The results were so favourable that Knight took a British patent and then sold licences to the German Daimler company, Minerva and Panhard. The British version of Daimler took the engine and enhanced it calling it the Daimler-Knight.
When the results of the RAC tests were publicised, many US companies flocked to Knight to licence the engines. Several companies like Columbia, Stearns and Edwards sold vehicles with licensed versions of the engine.
As with many early technologies in a market, the Knight was soon overtaken by new sidevalve engines that produced acceptable power outputs, were quieter than the earlier engines and were cheaper to manufacture. By the early 1930s, no company had renewed their licences for the Silent Knight. Willys-Overland were the last to use this type of engine and they stopped production of the engine in 1932. Knight, himself, died 8 years later in 1940.
The Silent Knight was an evolutionary branch of the internal combustion engine’s tree that didn’t survive however in recent years, the concepts of a sleeve valve engine have been researched further to see if it becomes viable again. Who knows, we might see a new type of highly efficient motor appearing in the coming decades. It all depends on which fuel source becomes dominant as fossil fuel usage becomes more and more politically incorrect.