When I was young, I always had the hots for the 450 thumper. I was totally intrigued with the desmo valve gear.
Growing up, I'd read about the wonders of the 50s Mercedes Benz W196 GP racers and the fantastic 300 SLR (that's "SLR," not the plain old "SL" gull wing).
Back in those old days, valve springs were a common point of failure. For instance, rodders doing up a Chevy stove bolt 6 would use Buick Straight 8 valve springs, because they were of higher quality. Increasing rpm levels put greater stress on valve springs, as did ever more aggressive cam profiles needed for high rpm. Desmo arrangements, while complex, seemed like the ticket in the 50s, as shown by the successes of Mercedes Benz racing.
People with more dollars than sense, like Lance Reventlow, sought to copy the desmo formula for success. Reventlow went to Meyer & Drake (who had bought "Offenhauser" from Fred Offenhauser) and had Leo Goossen draw up a desmo Offy for use in Reventlow's Scarab racers. Wonder boys Jim Travers and Frank Coon (the pair behind the legendary Traco engine builders) talked Reventlow out of big bucks to get Offenhauser to build a competitive desmo setup. The cam grinder was not used to grinding reverse cams and botched the job, and Travers and Coon had difficulties in learning to synchronize the cams, so a fair number of bent valves were the result.
Worse yet, the American mastery of power shown by the demonstration of Offenhauser powered racers at Monza in 1957 had reversed by 1960. The new American engine was lacking power, compared to the Europeans, and Reventlow's Scarab chassis didn't handle so well, either.
The desmo system was a dead end. Mercedes Benz dropped it. Old time Indianapolis racer Art Sparks, ever the innovator, developed the S&W spring that was made of vacuum-remelted wire to eliminate impurities and shot-peened to eliminate stress. Overnight, the rationale for the desmo valve system had disappeared, as the new S&W springs lived at the higher rpm and more radical cam grinds of the late 50s.
Ducati had gone with desmo valve gear after WW2 in the 125cc motorcycle class for the same reasons that Mercedes Benz selected it. They mastered the technology and didn't leave it behind when better valve springs became available. Their bikes were beautiful jewels in the Italian tradition of engineering that both "shows and goes," like this 450:
The cams used the aircraft-like shaft and bevel gear drive, light and elegant (no crude chain drive stuff here!):
Letting a barbarian like Hunter Thompson at a Ducati of any kind would be akin to letting the Marquis de Sade loose at a kindergarten. Ugh!
Hurray for Ducati! Wonderful machines!
