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–Bentley L-series V8 engine Flying Spur and Continental models. The first engine of V8 configuration was developed in 1904 by the Marmon Motor Car Company in the United States. It was experimental, however, and did not find its way into a passenger vehicle. Rolls-Royce premiered the world's second V8 engine in 1905 for their Rolls-Royce V-8 Legalimit – governed not to exceed the legal speed limit in Britain at the time of . It was not a success, with only three made and just one sold, which was soon returned to the factory to be scrapped. It was another decade before Cadillac pioneered a