“….. Others, among them BMW, Porsche, Maserati, OSCA and BRM tested desmodromic valve gear but never competed with it.”
“….. OSCA experimented with the technique as did BRM.”
Source: Classic Grand Prix Cars : The Front-engined Formula 1 Era 1906-1960 by Karl Ludvigsen (cop. 2000.
Resp. P. 31 and p. 169.
Tony Rudd (1923-2003) was a very talented key engineer at BRM and later Lotus. In his book (see picture) he mentions the BRM desmo-system. When I asked him for more documentation, I received (24.01.02) the following reply:
“Mr Cloosterman. BRM never built an engine with their system, intended for their 2.5 litre F1. 4 cylinder used 1954 to 1961. it was a double rocker system, one rocker opened and one closed like the Mercedes 8 cylinder of the same era. They built a rig and tested several configurations, all of which broke rockers. It was abandoned in 1955 when they began to expereince timing gear problems with the basic F1 engine for which it was intended. I personally never had much enthusiasm fo it. Tony Rudd”
Conclusion: BRM will have underestimated – like many others – the fantastic scientific approach of Mercedes’ W-196. They obviously even failed in copying the system. Certainly not something te be proud or enthousiastic about. The description in T.R.’s letter sounds like a very provisional prototype or blatant copy without a proper kinematic study. Something (design factor) was missed or ignored or slopped to achieve destruction of rockers (closers?). Design fault in material, chroming, structural form, conjugate synchronization. Maybe they just kept speeding it up until it broke for fun! The only passing mention of actual typology is of the generically cliché Mercedes-Benz. Example of amateurism here is where T.R. mentions getting distracted from the Desmo by having to focus back on solving the Gear-Train survival and the machined tolerances or vibrations, etc. Poor Desmo design would surely put more stress on a marginal GearTrain anyway. Not an interesting project to further investigate.
[Classification = Group 5] = Mercedes copy.