Norton BS review
D.R O'Donovan's work at the Weybridge track resulted in the introduction of tuned 'Brooklands' models in 1913, and these highly developed sports versions continued into the 1920s. According to its manufacturer, the Norton Brooklands Special (BS) was 'for those who desire exceptional power and speed for competition in a machine suitable for road work.' The BS engines were specially prepared by the factory, run-in on the track at Brooklands and 'certified to have exceeded 70mph for a kilo.' .
The study of combustion chamber shape, inlet and exhaust porting, compression ratios, cam profiles, and carburation were all in their infancy, and the best tuned Norton engines came from variations in the iron foundry process, rather than some intentional series of modifications to a standard motors. Some engines simply went better than others, and the quickest engines made their way to the racing team, or to selected tuners at Brooklands Special. More specs and user manual of Norton BS you can see in next overview.