Editing Rotary engine (section)

===Arrangement===
Like "fixed" radial engines, rotaries were generally built with an odd number of cylinders (usually 5, 7 or 9), so that a consistent every-other-piston firing order could be maintained, to provide smooth running. Rotary engines with an even number of cylinders were mostly of the "two row" type.

Most rotary engines were arranged with the cylinders pointing outwards from a single crankshaft, in the same general form as a radial, but there were also rotary [[boxer engine]]s<ref name = "Barry"/> and even [[single-cylinder engine|one-cylinder]] rotaries.