X-Mozilla-Keys:                                                                                 
Vance Jaqua wrote:

--- Paul <rotaryeng@earthlink.net> wrote:

As I recall Francesco told me they gave up on
titanium rotors.
Too much heat transfer causes a loss of power.

Now I

don't
know if a ceramic coating on the titanium rotors
would recover
some of that HP. Titanium rotors should allow

the

engine to run
up to 12,000 RPM or so I would guess.

Paul Lamar

Vance Jaqua wrote:

That is a strange answer Paul, titanium has about

the lowest thermal

conductivity of all the common structural metals

Ti 5, cast iron 28,

carbon steel 27
stainless steel 10 ,alum 100 etc Titanium makes

super camping coffee

cups - reduce burned lips
Vance

Wow! Sounds like I got it ass backwards. He
mentioned thermal and
I assumed it was the other way around. Perhaps the
tip seals ran too
hot or the surface of the rotors ran too hot. I will
have to call
Francesco and see if he knows more about it.
How about thermal expansion.
How does ti compare with aluminum?
If the conductivity is low is the distortion high?

Paul Lamar

Thermal expansion is reasonably low about 5 X 10-6
as compared to alum about 13. 

High silicon (for pistons etc) drops it to below 10.  
Aust stainless about 9.
Martensitic about 5.5. 
Carbon steel about 8.
Cast iron about 6.

Distortion for ti is probably not a serious problem.
Notch sensitivity is - Vance

Its a mystery then why titanium rotors do not work. I will have to
look into this further. If nothing else it could save ten
pounds in a two rotor.

Paul Lamar
 
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