Rolls-Royce–Bentley L-series V8 engine as the "six and a quarter" litre engine. When new, the Rolls-Royce/Bentley V8 was rumoured to be an American engine design licence-built, but it was developed in-house by Rolls-Royce and Bentley engineers. This can be seen in its design characteristics, with features like an aluminium alloy cylinder block with wet liners, gear-driven camshaft, (initially) outboard spark plugs and porting inspired by the Rolls-Royce Merlin aircraft engine. The bore spacing of 4.75" was unlike any American V8 engine and the firing order was 1-5-4-8-6-3-7-2 something uncommon in any period American OHV V8. The deep skirted crankcase design is also rare with
Rolls-Royce Eagle XVI aircraft industry where it was felt that the unusual layout would block the pilot's forward view in a typical fighter aircraft installation. The project was dropped and development efforts then concentrated on the Kestrel. Like the Crecy the Eagle XVI was one of the few Rolls-Royce projects that did not fly, it is of note that the 'X' engine layout was reused in the later Vulture and Exe designs. Rolls-Royce Eagle XVI The Rolls-Royce Eagle XVI was a British experimental 16 cylinder aero engine designed and developed by Rolls-Royce Limited in 1925. The engine was test run but did not