Editing Straight-twin engine (section)

{{short description|Inline piston engine with two cylinders}}
[[File:Rovena 250 1964 - Hispano Villiers Engine.JPG|thumb|right|1964 [[Sanglas#History|Sanglas Rovena]] motorcycle engine (built by Hispano Villiers)]]
[[File:1997SuzukiGS500E-engine.jpg|thumb|1997 [[Suzuki GS500]] motorcycle engine]]

A '''straight-twin engine''', also known as an '''inline-twin''', '''vertical-twin''', '''inline-2''', or '''parallel-twin''', is a two-cylinder [[Reciprocating engine|piston engine]] whose cylinders are arranged in a line along a common crankshaft.

Straight-twin engines are primarily used in motorcycles; other uses include automobiles, marine vessels, snowmobiles, [[personal watercraft|jet ski]]s, all-terrain vehicles, tractors and ultralight aircraft.

Various different crankshaft configurations have been used for straight-twin engines, with the most common being 360 degrees, 180 degrees and 270 degrees.