Paul, The CLE of pure Ti is 4.9 x 10-6th/deg F.

BTW Paul Ti-6al-4v is the most common alloy with a bit higher
expansion rate. I incorrectly read the expansion rate the
first time converting from micromillimeters/deg C etc sorry.
Bill Jepson

That is what I suspected. A solid silicon nitride ceramic insert
would be ideal. Hard, very smooth  and no expansion to speak of. Don't know
what the thermal conductivity would be. The cost would be astronomical
I am sure. Same stuff super high speed ball bearings and apex seals
are made of.

Paul Lamar

So you are saying that you want the plate to float in the end housing?  You
don't want it to expand at all and try to keep up with the expansion of the
rest of the engine?  I understand not wanting any warpage but if the
expansion is too small you will have some sealing or fretting problems maybe?

Mike McGee, RV-4 N996RV, O320-E2G, Hillsboro, OR
13B in gestation mode

No not float. It does need to be pinned to locate it.

The expansion would be OK if the temperature of the plate was uniform 
and homogenous over its entire surface. If you heat a metal disc
only on its periphery it will tend to distort out of plane in the
mathematical meaning of the word. Low conductivity of the metal
will amplify this effect.

I am not sure this problem is going to necessarily occur. I am just
thinking ahead.

The overall expansion, at say a wall temp of 220 F or so, would not amount
to much. In any event there is a large difference in the expansion rate of 
the aluminum rotor housing, the current cast iron end housings
and the steel rotor housing wear surface.

This tends to bow the rotor housing wear surface slightly and Mazda crowns
the apex seals slightly to compensate.

Paul Lamar
 
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