dragula

This was taken from a post of a freind on a dif. site, but we have been looking at this in ps/comp stuff for a while, but could never figure out this "hidden dynamic".

This dosent explain whats happening, but I thought yall might enjoy some insight in how complex this shit can get.

Technical Editor Kevin Cameron relates an issue mentioned to him by a Ducati race engineer. Bench testing had revealed a steep rise in valve gear friction at 12,000-12,200 RPM which defied conventional explanation. Festooning the head with rotary encoders on the cams, laser displacement gauges on the valves, etc, they discovered that the twist and bend resonant frequencies were so extreme that as it traded energy with the opening and closing valves, the instantaneous RPM of the cam was going from 5800 to 6375 rpm!

V-8 cams of course have more valve-induced torque spikes per rev and thus more uniform motion than a V-2 (actually, 'V-1" for cam purposes) but are ~ 6X as long...

The same column discussed plain bearings Vs. rollers and noted a recent trend to the former in such diverse applications as rocket engine turbo pumps, high-end grinder spindles, ICBM guidance gyros and yes, Ducati race bike camshafts. An interesting contrast to the upper levels of American motorsports...


Intresting...

DEATH ZEPPELIN

yeah thats a head scratcher