I haven?t read anything on a high compression rotary combustion chamber
shape.  What does it look like?  What is impractical

about the higher

ratios?

Eric,

 The reason super high compression ratios are impratcial in the rotary 
are two-fold. First, The combustion chamber shape is defined by the sweep 
of the tip seals. The Throcoid shape isn't changed without building a 
completely new engine. Bulging the rotor more to create high compression 
is limite by the "bump" in the outer housing. All this leads to the other
 problem created by high compression in the rotary, the long thin combustion 
chamber shape. Flame propogation tests done by several engine manufacturers 
show that when the distances between surfaces gets much below .010 inches 
the flame simply goes out. This happens even with a "burnable" mixture. 
The piston engine 2 cycle guys found there is a real limit on the minimum
height of the squish band. (The conical area surronding the combustion chamber 
itself) Combustion chamber shape is the one area where piston engines have 
an advantage over the rotary. (One of the few.)
 For higher output in t the rotary a "safe" rotor to housing distance 
and super or turbocharging is the way to go. Just My $.02 Bill Jepson

 
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