motobaleno wrote:Tommy Cookers wrote:the late Prof Blair's work showed that mechanical springs were ok in at an 18000 over-rev of the Ducati Moto GP
with finger followers (but not with direct tappet actuation)
2014 cylinders are roughly that size
ducati does not use springs. it uses desmodromic distribution.
Prof Blair did work for Ducati on race (Moto GP?) induction systems, his prime field of expertise
the valve work was his own
yes I know how Ducati has been operating its valves (since 1958 or so)
he says that pneumatic valve springs work by having some designed-in bleeding of gas, ie they are lightly damped thereby
without this damping they do not work so well
this is could be seen as hysteresis