The Knight Sleeve Valve Engine Was Charmingly Weird

Karolis Kavolelis/Shutterstock

Automobiles were still successful their comparative infancy successful 1905, but they had been increasing much celebrated for years. There was a problem, though: they were highly noisy. One origin of nan sound were nan poppet valve caps and springs that would unfastened and adjacent entree to nan intake and exhaust valves. Charles Knight, an American inventor, sought to lick that problem by building an motor pinch nary valve springs whatsoever.

The Knight Sleeve Valve Engine replaced valve caps and springs pinch reciprocating sleeves placed astir nan cylinders. The consequence was an motor that was truthful overmuch quieter than accepted engines that it would beryllium dubbed nan "Silent Knight." But American automakers weren't impressed, truthful Knight shopped it astir Europe, wherever it would drawback connected pinch companies for illustration Mercedes and Daimler. Knight would licence his motor to respective automakers connected nan continent, limiting nan licensing to 1 institution per country.

Fast guardant a fewer years, and American automakers would commencement to show liking successful Knight's engine, arsenic well. He would licence it to aggregate U.S. companies, but Willys-Overland would go nan astir successful pinch nan engine, trading arsenic galore arsenic 50,000 Willys-Knight models per year. In nan minds of some, it looked for illustration nan aged poppet valve engines would soon spell retired of style. After all, this was an era of invention for nan combustion motor — it would beryllium astir this time, for example, that nan 7-cylinder Gnome rotary engine was invented for airplanes.

You mightiness deliberation nan conception down this motor was simple, but that couldn't beryllium further from nan truth. Basically, nan motor worked for illustration this: alternatively of noisy poppet valve caps and springs, each cylinder was surrounded by 2 sleeves. 

Each sleeve had slits astatine nan top. The sleeves were timed to move up and down to facilitate each shape of nan piston stroke. During nan intake phase, nan sleeves were positioned truthful that nan slits lined up pinch nan opening to nan intake port. And during nan compression phase, nan sleeves were positioned truthful that nan openings to nan ports were blocked. Then, of course, nan ignition would happen, pushing nan piston backmost down. This would lead into nan exhaust phase, during which nan slits were lined up pinch nan opening to nan exhaust port. That creation mightiness look weird, but it's not arsenic weird arsenic nan Wankel rotary engine. Simple aliases not, nan sleeve valve conception was elegant. It was besides fuel-efficient for its time. 

In 1913, Théodore Pilette entered his Mercedes-Knight 16/45 hp successful nan 500 Miles of Indianapolis. It had nan slowest qualifying time, but it sewage in. The car ended up successful an awesome 5th place, successful portion because it ne'er had to make a pit stop.

The Knight Sleeve Valve Engine solved immoderate problems presented by nan poppet valve engines, but location were trade-offs. The motor was very costly to manufacture, apt because it was dense and besides because nan exertion was very analyzable for nan time. That's why Willys-Overland sold its Willys-Knight arsenic its premium model, while producing accepted poppet valve models for mean consumers. The Knight engines utilized a batch of oil as well, producing rather a spot of fume down it arsenic a result.

In nan meantime, improvements were being made successful nan manufacturing of nan accepted poppet valve engines. Those problems solved by nan Knight Sleeve Valve Engines would yet nary longer beryllium successful accepted engines. There conscionable wasn't a feasible logic anymore to make nan finance successful a smoky, costly lipid guzzler. 

Willys-Overland would discontinue nan Willys-Knight successful 1932, nan aforesaid twelvemonth nan Knight patents would expire. By that time, motorists and automakers alike had already moved on, and nan motor that erstwhile powered hundreds of thousands of vehicles connected nan roadworthy would gradually time off nan public's consciousness. That doesn't mean combustion invention is dead, though. To spot what we mean, publication astir nan tiny two-stroke INNengine E-REX.