I have a suspicion that an all alloy rotor would have problems
with keeping the fit of the pressed in e-shaft bearing with the rotor
expansion and contraction due to temperature. I was considering using
what I would call a flanged sleeve made of steel to mount the bearing
and stationary gear. The stationary gear fits into the face of the
flange, the bearing in the bore, and the alloy rotor fits over the
outside of the sleeve with dowel pins into the back side of the flange.
It doesn't appear too dificult to CNC the negative patterns to cast the
wax as a left and right side with the wax sections keyed together. The
difficult part is machining the side seal grooves which was a major
stumbling block for rotamax. I was thinking of a router motor swinging
in the proper arc over an indexing table but reading how much trouble
others have had with this it is obviously not that easy. Useing 398 for
the rotor doesn't seem to be a problem as far as galling with side
housings of the same material because the side inner and outer oil seals
keep the parts separated. Temperature control of the rotor might require
a modified control of an increased oil flow thru the rotor from the
stock Mazda design although a prototype  of the stock type would be
tried first. Alloy parts with different compression depressions would
reuse the same flanged sleeve.


george grimes

There is a steel insert in Jeff's design for the rotor bearing.
The side seal grooves are a piece of cake for an NC mill.
Mazda mounts 3 rotors on a pallet and rotates the pallet to cut
three groves at a time with a broach.

Paul Lamar Graduate of a course in NC machining :)