Aviation Rolls Royce Merlin Crankshaft scarce technical drawing for the Griffon V1 series V12 aero engine, used on the Supermarine Spitfire a scarce print of the original, titled Crankshaft, displaying GN 4814 and dated 22/07/194, with a signature and date GRIFFON Sept 42 to the print (facsimile), depicting various sections of the crankshaft including dimensions, tolerances and material types, a very clear drawing, in good condition, with minor tears to edges but clean, folds out to 83.5 x 134cm approx. Note: The Rolls Royce Merlin is a British liquid cooled, V12 piston aero engine, a limited design and built as a private venture. Initially known as the PV-12, it was later called the Merlin following the company convention of naming its piston aero engines after birds of prey. Some of its major applications include Avro Lancaster, Handley Page Halifax, Hawker Hurricane and de Havilland Mosquito.