If you get this rag, the article is written by Kevin Cameron called
"Tales of the Testastretta".
Basically Ducati ran up against a RPM limit of 12,200RPM due to
excessive valve train vibration /resonance at this speed on their 996.
At that time they'd apparently been using ball & roller bearings
somewhere up top and the result was a lack of stiffness that was fixed
by going to plain bearings and tightening clearances. Anyway this is
plolly the main reason that those big twins are relatively competitive
on a one up basis with 4's in WSB.
Theoretically twins can never match 4-cylinder high RPM performance
and 4's can never match the low RPM twin performance. This is due to
VE=high velocity flow, area rule & size/weight in their perspective
valve train vs. piston sizes but apparently Ducati has come closer to
a theoretical max for a big valve engine than anyone else due to
optimizing their desmodromic valve trains. However, torque curves
don't lie and they still start to lose steam up top compared to the
four cylinder bikes that are running up to 18K RPM with valve spring
technology as are the V4 Ducati's when they're scaled down to the size
of the rest of the fours. Actually I believe some of the MGP 800cc
mfgs are using pneumatic valve actuation now.
Someone suggested that Ducati made better MGP frames but watching the
races during this year, the Ducati's seemed to have more power down
the straights (kind of like Spies & Maladdin running away from the
fact in AMS SB), so I think the Ducati fours were making considerably
more power than the rest, else Rossi and the boys would have had a
better chance keeping up. It's been clearly a technical cue this year
for Ducati & company & not necessarily just better riding, like back
when Rossi switched to riding for Yamaha instead of the superior HP V5
of Honda.
If you don't like technically related stuff (which many of you don't
in AMS) then skip this one ...No one's posted a new thread since
Sunday, I believe, so consider this filler for a news group hell bound
of sub thread jacking (mostly OT political or gory in nature).
Bob Nixon.
PS. I know there is one more race in Sepang this season but things are
pretty well sewed of for the winner-
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