A straight-twin engine, also known as an inline-twin, vertical-twin, or parallel-twin, is a two-cylinder piston engine whose cylinders are arranged in a line along a common crankshaft.
1964 Sanglas Rovena motorcycle engine (built by Hispano Villiers)
1997 Suzuki GS500 motorcycle engine
1938–1966 Triumph Speed Twin
1973–1975 Yamaha RD350 two-stroke motorcycle
A V-twin engine, also called a V2 engine, is a two-cylinder piston engine where the cylinders are arranged in a V configuration and share a common crankshaft.
Honda Shadow VT 125 motorcycle engine
"Fork & blade" connecting rods
1902 Princeps V-Twin (air-cooled)
1933–1939 Sokół 1000 (air-cooled)