Editing Opposed-piston engine (section)

{{Short description|Combustion engine using disks compressing fuel in the same cylinder}}
{{For|horizontally-opposed engines|flat engine}}
{{Use dmy dates|date=May 2024}}

[[File:Simpson's Balanced 2-Stroke of 1914 high-res animation.gif|thumb|upright=1.5|A 1914 Simpson's balanced two-stroke engine]]

An '''opposed-piston engine''' is a [[piston engine]] in which each [[cylinder (engine)|cylinder]] has a [[piston]] at both ends, and no [[cylinder head]]. Petrol and diesel opposed-piston engines have been used mostly in large applications such as ships, military tanks, and factories. Current manufacturers of opposed-piston engines include [[Cummins]], [[Achates Power]], and [[Fairbanks-Morse|Fairbanks-Morse Defense (FMDefense)]].