Editing Variable valve timing (section)

===Aircraft===
An early experimental 200&nbsp;hp [[Clerget]] V-8 from the 1910s used a sliding camshaft to change the valve timing{{Citation needed|date=October 2019}}. Some versions of the [[Bristol Jupiter]] [[radial engine]] of the early 1920s incorporated variable valve timing gear, mainly to vary the inlet valve timing in connection with higher compression ratios.<ref>{{cite web | last = Arthur W. | first = Gardiner |author2=William E. Whedon  | title = REPORT No. 272: THE RELATIVE PERFORMANCE OBTAINED WITH SEVERAL METHODS OF CONTROL OF AN OVERCOMPRESSED ENGINE USING GASOLINE | publisher = [[Langley Research Center|Langley Aeronautical Laboratory]] | date = 25 February 1927 | url = http://naca.central.cranfield.ac.uk/reports/1928/naca-report-272.pdf }}</ref> The [[Lycoming R-7755]] engine had a Variable Valve Timing system consisting of two cams that can be selected by the pilot.  One for take off, pursuit and escape, the other for economical cruising.