The Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litre capacity. Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12, it was later called Merlin following the company convention of naming its four-stroke piston aero engines after birds of prey. The engine benefitted from the racing experiences of precursor engines in the 1930s.
Rolls-Royce Merlin
Parallel valve Merlin cylinder head
Merlin 55 ejector exhaust detail, Spitfire LF.VB, EP120
Preserved Merlin 63 showing intercooler radiator, supercharger and carburettor
A V12 engine is a twelve-cylinder piston engine where two banks of six cylinders are arranged in a V configuration around a common crankshaft. V12 engines are more common than V10 engines. However, they are less common than V8 engines.
1991 Porsche 3512 Formula One engine
1904 Craig-Dörwald racing boat engine
Two large marine engines
1917 Liberty L-12 airplane engine