> Hard to say really. I don't really believe numbers that are thrown
   > around without an actual design study behind them. Cast Ti has anywhere
   > from a 1/2 to a 1/3 less
    thermal conductivity versus cast irons. 40
   > percent less density, half the expansion rate, double to triple the
   > tensile strength but anywhere from equal to half the modulus of
   > elasticity. If i were just looking at it, without changing any
   > dimension(based on modulus vs. tensile) it would be about 40 percent of
   > the weight of the rotor. So that is my unfounded look at things that
   > will eventually be looked at.
   >
   > NASA did it but from Stainless to Ti and assuming they did it right,
   > which is a fair assumption, they went from 10.7 lbs to 7 lbs which is 35
   > percent reduction.
   >
   > You put that back in my fake math and that means from cast iron to Ti
   > which has less difference in densities and the new fake math we will say
   > is 30 percent. 9lbs at 30 percent reduction gets you to 6.3lbs.
   >
   > The answer to your question is light as shit comparatively.
    Better
   > solution to aluminum, not that I think it is a solution at all in my
   > opinion. Which leads me to another direction. All of this "we can
   spin
   > it to 20k rpm and make 900hp" thing is not the right direction in my
   > opinion. You actually have to attach the engine to things like clutches,
   > prsu's etc. which makes for very large problems in taking the speeds.
   > Can be done in F1 for short periods but if anyone thinks they can spin
   > the engine that fast and make it last is kidding themselves. In order to
   > spin that fast the journal bearings in their engines have to be super
   > high tolerance which means at room temperature then engine is siezed. F1
   > engines have to have special oils circulated at higher than normal temps
   > for conventional oils before you can even start them. Yeah it works in
   > jet engines but they dont have the torque variances an ICE has. Even
    an
   > engine as relatively smooth as a rotary. Fantasy arm chair engineering =
   > usable 20k rpm wankel of any reasonable car engine size.
   >
   > The right direction I feel is this. If you can make a rotor that light
   > then you should make the engine bigger and take advantage of greater
   > torque and power. Lets say you can get away with a 9 lbs Ti rotor in a 1
   > liter per rotor engine that can rev to 8000rpm. Playing with some
   > numbers on the side it looks like this could be possible but again until
   > it is actual gone through a complete design study it is all arm chair.
   >
   > The only way to get to that design study is learn how the whole thing is
   > designed from the ground up and that is what I am doing. As soon as I
   > get past this part I will move on to design studies of size and strength
   > of rotors in different materials. So while I am doing that and
   > contacting
    Howmet we will see.
   >
   > Rob Woods

   Rob,
   Just got out of hospital from cancer surgery - I love your thinking. I'm
   looking forward to information from your research. Just reading your
   'stuff'
   makes me feel better.
   Love it!
   George ( down under)

   Sorry to hear that George. Get well soon.

   Paul Lamar

George,

Hope your recovery goes well. I hope that my looking into things leads
to something different or better but it might just work out that there
is nothing to be gained. I think with pooling of resources and ideas a
better solution might be able to be worked out.

Rob Woods