Boingers

[Zack]

> There are other ways of reducing the loss due to
> forcing a few ounces of metal bounce back and forth.  You could hold
> the crank still and rotate the cylinders.  I believe the British
> made an engine that did that.

Ray,

If you hold the crank still, you -still- have that metal 
bouncing back and forth.  You cannot, even in theory, create a piston 
engine with perfect dynamic balance.  You can in theory achieve 
perfect dynamic balance in a rotary engine, and some designs have in 
fact achieved this (the Moller Rotary for one), though most have not 
(the dynamic balance of Mazda's rotaries is not perfect).
.	As for the rotary piston engine (which cannot be dynamically 
balanced) lots of people made rotary piston engines, not just the 
British (the rotary kind on the old WWI planes, where the entire 
engine rotated around the stationary crankshaft).  They were a very 
unfavorable design for lots of reasons, and didn't last very long.
	In all honesty, I think the jury is still out on the Wankel.  
There's no getting around the fact that the power output per unit 
volume and per unit weight is -much- higher than for a piston engine. 
The only reason you don't see bigger rotary engines in terms of total 
output is because of the fuel consumption issue.
  	Mazda claims to have made great improvements in both efficiency 
and power output with the MSPRE, and Moller is now marketing a rotary 
that is demonstrably as fuel efficient (if not more) and has lower 
emissions than most piston engines.  Whether either of these will 
actually make it to the automotive market and prove practical and 
durable remains to be seen, but the prospects are certainly 
interesting.  ( A tiny Moller rotary tied to a generator in a hybrid 
electric vehicle would be -extremely- interesting ).
	Whatever bad things one may say about the rotary, and 
there are plenty of justifiable criticisms, it has survived far 
longer in the automotive market than any comparable "alternative" 
powerplant that I can think of.

Z