Editing Atkinson cycle (section)

==Atkinson "Utilite Engine"==
[[File:Atkinson utilite engine.jpg|thumb|Atkinson Utilite Engine]]
[[File:Atkinson's Utilite' engine 1892.png|thumb|Atkinson's Utilite engine 1892]]

Atkinson's third design was named the "Utilite Engine".<ref>{{cite book |title=The gas, petrol, and oil engine, Volume 2 |first=Dugald |last=Clerk |page=210 |url=https://books.google.com/books?id=aB9YAAAAYAAJ&q=The+gas%2C+petrol%2C+and+oil+engine%2C+Volume+2+By+Dugald+Clerk |year=1913 |publisher=J. Wiley}}</ref> Atkinson's "Cycle" engine was efficient; however, its linkage was difficult to balance for high speed operation. Atkinson realized an improvement was needed to make his cycle more applicable as a higher-speed engine. 

With this new design, Atkinson was able to eliminate the linkages and make a more conventional, well balanced engine capable of operating at speeds up to 600 rpm and capable of producing power every revolution, yet he preserved all of the efficiency of his "Cycle Engine" having a proportionally short compression stroke and a longer expansion stroke. The Utilite operates much like a standard two-stroke except that the exhaust port is located at about the middle of the stroke. 

During the expansion/power stroke, a cam-operated valve (which remains closed until the piston nears the end of the stroke) prevents pressure from escaping as the piston moves past the exhaust port. The exhaust valve is opened near the bottom of the stroke; it remains open as the piston heads back toward compression, letting fresh air charge the cylinder and exhaust escape until the port is covered by the piston. 

After the exhaust port is covered the piston begins to compress the remaining air in the cylinder. A small piston fuel pump injects liquid during compression. The ignition source was likely a hot tube as in Atkinson's other engines. This design resulted in a two-stroke engine with a short compression and longer expansion stroke. 

The Utilite Engine tested as even more efficient than Atkinson's previous "differential" and "cycle" designs. Very few were produced, and none are known to survive. The British patent is from 1892, #2492. No US patent for the Utilite Engine is known.

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