Editing Aircraft engine (section)

====Combustion cycles====
Starting in the 1930s attempts were made to produce a practical [[aircraft diesel engine]]. In general, Diesel engines are more reliable and much better suited to running for long periods of time at medium power settings. The lightweight alloys of the 1930s were not up to the task of handling the much higher [[compression ratio]]s of diesel engines, so they generally had poor power-to-weight ratios and were uncommon for that reason, although the [[Clerget aircraft engines|Clerget 14F Diesel radial engine]] (1939) has the same power to weight ratio as a gasoline radial. Improvements in Diesel technology in automobiles (leading to much better power-weight ratios), the Diesel's much better fuel efficiency and the high relative taxation of AVGAS compared to Jet A1 in Europe have all seen a revival of interest in the use of diesels for aircraft. [[Thielert]] Aircraft Engines converted Mercedes Diesel automotive engines, certified them for aircraft use, and became an OEM provider to Diamond Aviation for their light twin. Financial problems have plagued Thielert, so Diamond's affiliate&nbsp;— Austro Engine&nbsp;— developed the new [[Austro Engine E4|AE300 turbodiesel]], also based on a Mercedes engine.<ref>{{cite web
|url = http://www.flyingmag.com/pilot-reports/pistons/diamond-twins-reborn
|title = Diamond Twins Reborn
|publisher = Flying Mag
|access-date = 2010-06-14
|archive-url = https://web.archive.org/web/20140618032748/http://www.flyingmag.com/pilot-reports/pistons/diamond-twins-reborn
|archive-date = 2014-06-18
|url-status = dead
}}</ref>