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New Design for Fuel Efficient Piston Engines
Home » Bourke Technology 
Bourke Engine Uses Piston Dwell
During the 1940s and 1950s, Russell Bourke's attempt to advance piston engine technology by using the "scotch yoke" to increase piston dwell was not well received by industry. He was without doubt ahead of his time, and as many believe, if given the opportunity, Bourke’s technology would have been successful for some important engine applications. His engine advancement was apparently considered too challenging and risky for the Automotive Industry to take seriously. Many engine enthusiasts had hoped that Bourke would overcome the bias of the engine industry, the main problem he often faced, when presenting his ideas. Nevertheless, Bourke accomplished much of his objectives and proved through his various prototype models that added piston dwell during combustion greatly increases engine performance for both fuel economy and power. Those of you who might be interested in some of Bourke’s accomplishments, can read selected articles in Hot Rod Magazine, July and September 1954, for example. Numerous articles of Bourke’s day were published in various other magazines and publications, and also “Bourke’s Documentary” is available on the Internet which describes his accomplishments. Many have attempted to improve Bourke’s engine, but to date, except for Fisher’s yoke-arm, no one has found a way to introduce the necessary added piston dwell during combustion to provide the superior performance which has and continues to elude engine manufacturers. Some main stream automotive manufacturers have attempted to improve the Bourke engine by introducing a "yoke-slider", but achieved limited success. Automotive companies which have implemented or researched the yoke-slider are CMC, Toyota, BMW, VW, SAAB, Benz, Fiat, as examples. CMC or Collins Motor Corporation has achieved the most success with some limited production and test cars in Europe and elsewhere. It appears that these and other companies have not looked beyond the Bourke concept because their intent and focus were apparently just on the improvements of mostly the “slider” arrangement. And as a result, no new or practical mechanical improvements have yet been devised from them or anyone. Fisher has developed a new approach which not only overcomes the disadvantages of the "Bourke Technology", but also has substantially simplified everything by adding, in essence, only one component part to the existing conventional engine which is called a yoke-arm. The result has been superior performance compared to Bourke and with the added advantages of many different cylinder arrangements such as the single cylinder, opposed, V-type, in-line and radial for aircraft. Therefore, the Fisher's yoke-arm has replaced Bourke as the next level of superior performance for automotive and other piston engine applications.

Although Russell Bourke was ahead of his time, the engine technology of his day was not what it is today. The industry of today has found limited ways to improve engine performance by redesigning various peripheral components like electronic control systems, fuel injection systems by adding stratified charging and the like, combustion chambers for improved combustion efficiencies and such to increase engine performance and fuel economy. However, the Automotive Industry in particular, and the engine industry in general, have not found a break-thru technology that will carry engine performance to a new level into future generations. The new level similar to what Bourke was trying to achieve during his day. Fisher's yoke-arm has not only surpassed Bourke, but has substantially surpassed improvements provided by the engine manufacturers of today. The yoke-arm affords added piston dwell in excess of five times what Bourke was able to achieve with his harmonic motion or Bourke-Cycle engine design. Also, the Bourke engine has a mechanical disadvantage compared to conventional engines of today where as Fisher's yoke-arm has a significant mechanical advantage plus much less piston friction compared to Bourke and conventional. So, Fisher has “leap frogged” both Bourke and conventional by just adding a single component part, the yoke-arm. It is beyond the belief of many that Fisher's yoke-arm technology has been missed by the World’s automotive and engine manufacturers. Fisher has acquired both US and foreign patents. And Fisher Technologies is currently in the final stages of development to reconfirm what computer modeling and preliminary prototype testing have proven about the superiority of using a yoke-arm to advance engine performance for future generations.


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