[Ducati] 17000 RPM MotoGP Limit?

[Peter Bonner]

Well said Alex.

The real trick will be eliminating poppet valves somehow (rotary valve?) or
at least the cam and follower train stuff.

To illustrate the difference Alex is talking about, get ahold of two Ducati
heads, one desmo, and one spring type Try to turn the camshaft over using a
wrench on the cam nut. There is a cycle of resistance as whatever spring is
compressed (coil, hairpin, or pneumatic) but no peak of resistance with the
desmo heads. Now imagine turning at 19k rpm and compute the required
horsepower, especially with multiple valves/cylinders.

Incidentally, awhile back Honda did mention looking at various valve
systems, including desmo, but can't you just imagine the hoots of derision
while they eat that nasty bit of crow?

Peter


----- Original Message ----- 
From: "Alexander M Ortner" <aortner264789mi at comcast.net>
To: "'Ducati Owners Group'" <ducati at ducati.net>
Sent: Tuesday, March 11, 2008 3:19 PM
Subject: RE: [Ducati] 17000 RPM MotoGP Limit?


> Pneumatic motors run higher pressures than coil springs. And the pressure
is
> linear not progressive. Let's say a coil spring is 100 lbs per inch at two
> inches of travel it takes 200 lbs to push the spring down and
significantly
> more pressure. A pneumatic spring will start out at 200 lbs and won't go
up
> as significantly as a coil spring so the total pressure is greater as is
> frictional losses. So why is pneumatics better because at 200 lbs the
valve
> doesn't float off the cam it is under better control and more radical cams
> can be ground for pneumatic valves than with springs. The pneumatics is
> horse power sucker if it wasn't for the radical cams. Desmo has the best
of
> both worlds radical cams and very low friction. I have it from a good
source
> that Ducati engines are turning over 20,000 rpm in the lab now.
>
>
> Alex Ortner
> I can’t go back and fix my mistakes
>
>
>
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