There was once a time when Desmodromic valve technology was cutting edge and a necessary competitive advantage for Ducati in racing. The Desmo head doesn’t use a valve spring to return the valve to the closed position, instead relying on a second valve rocker and a second lobe on the camshaft to...
well I wasn’t saying the springs waste energy. I’m just saying that one engine valve design method requires more work energy than the other with respect to engine performance. overall valve open/close efficiency. it takes work energy to compress the springs. True it is transformed to potential energy once the springs are compressed and back to kinetic energy when closing (no additional work required to close the valve) but it still takes the work to do the compression. the desmodromic system does not therefore a more efficient design. In the video the rider even comments on how much easier the engine is to rev. Supposedly you can rotate the valve cycle by hand on the Ducati engine where spring based valve systems would typically require a tool with mechanical advantage to do so with the engine off.
I was intended to eliminate valve float at high RPM. Especially with high lift cams. Had no idea it was as old as 1896. Makes sense though as I imagine spring metallurgy back then was not as good as today's alloys.
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