Editing V12 engine (section)

=== 1900s to 1930s ===
{{multiple image
| align     = right
| direction = vertical
| width     = 220
| image1    = Liberty V12.jpg
| caption1  = 1917 [[Liberty L-12]] airplane engine
| image2    = Renault130hp.jpg
| caption2  = Renault 12Dc airplane engine, circa 1925
}}

[[Renault]] introduced the first V12 engine for aircraft with their [[Renault 90 hp|90 hp model of 1912]]. This engine had a V-angle of 60 degrees, air cooling and an [[IOE engine|intake over exhaust]] (F-head) valve arrangement. The propeller was driven from the front end of the camshaft, thus spinning the propeller speed at half the speed of a typical crankshaft driven propeller, in order to improve the propeller efficiency.<ref name="Ludvigsen"/> The Renault engine was closely mimicked by the [[RAF 4]] and its derivatives,{{citation needed|date=February 2020}} which was used by various British military aircraft during World War I. The RAF 4 engine had a displacement of {{convert|13.2|L|cuin|0|abbr=on}}, weighed {{convert|637|lbs|kg|0|abbr=on|order=flip}} and produced {{convert|140|hp|kW|0|abbr=on|order=flip}} at 1,800 rpm.

In March 1914, a prototype version of the [[Sunbeam Crusader#Variants|Sunbeam Mohawk]] V12 engine was unveiled in the United Kingdom, based on the 'Toodles V' motor racing engine. The production version was rated at {{convert|225|hp|kW|0|abbr=on|order=flip}} at 2,000 rpm, making it the most powerful airplane engine in Great Britain at the outbreak of World War I.<ref name="Ludvigsen"/> During and after World War I, various companies in the United States produced the [[Liberty L-12]] engine. In Austria, the [[Austro Daimler]] V12 engines were used by the large flying boats of the Naval Air Force and produced up to {{convert|345|hp|kW|0|abbr=on|order=flip}}. By the end of World War I, V12s were well established in aviation, powering some of the newest and largest fighter and bomber airplanes.

After World War I, many [[Zeppelin]]s used V12 engines built by [[Maybach]] and [[Daimler-Motoren-Gesellschaft|Daimler]]. V12 engines powered the first transatlantic crossings by the Curtiss NC flying boats (using four Liberty L-12 engines), the first non-stop transatlantic crossing in a Vickers Vimy (using two [[Rolls-Royce Eagle]] engines) and the first transatlantic crossing by an airship in the R-34 class airship (using five [[Sunbeam Maori]] engines).