Boingers

[Zack]

> I can't argue with that.  But I would still like a really nice direct
> injection 2-stroke!

I certainly wouldn't object if someone tried it.

> > Anyone care to compare the state of the art in rotaries today 
> >vs. the state of the art in pistons around 1910?
> 
> You know as well as I do that is not a valid comparison!  One of 
> the main reasons that engines have improved as much as they have
> isn't so much the specifics of the design!  It is the material science 
> behind it.

In all honesty I think it is.  For all practical purposes, there 
aren't any materials used in a 1998 production piston engine which 
weren't used in cars 30 years ago, and in aviation engines even 
further back.  In fact, if you plot fuel efficiency (BSFC) and 
specific output (per engine weight and displacement) of piston 
engines used on production cars in this country, the figures achieved 
by the very late 60's were as high, or nearly so, as anything made 
today.
  	Then, we all know what happened.  Increasingly strict 
emissions controls and restriction of allowable lead levels in fuel 
lead to a precipitous drop in engine compression ratios, fuel 
efficiency, and power output.  Vast improvements in the design of 
emissions control devices (the replacement of extremely restrictive 
pellet and other type cat. convertors with free-flowing honeycomb 
types...), replacement of carburetors with port fuel injection and 
computer engine management, have brought us to the point where 
engines have again reached levels of power and efficiency they 
had 30 years ago.  Strap a modern EFI system on a 30 year old engine 
block and you will see dramatic increases in performance and fuel 
efficiency, without changing anything in the engine from a materials 
science point of view. 
	Multi-valves per cylinder, alloy heads, pistons, and engine blocks, 
variable valve timing, almost everything you can think of that most 
people associate with "new" technology in piston engines, has been 
used before on piston engines long before I was even born.  And if 
you read some of the books on all the mind boggling array of weird 
variations on piston engines that people researched in WW2, you'll 
come to realize that almost everything anyone has ever thought of or 
will think of has been tried where it comes to piston engines.
	By contrast, if you look at the design of Mazda's MSPRE, you're 
looking at a design which is dramatically different from anything 
anyone else has used on a rotary, and the result is a normally 
aspirated 1.3 liter rotary that puts out 40 horsepower more than a 
-turbocharged- 1.3 liter did 10 years ago, with better fuel 
efficiency than the NA's of 10 years ago.
	If you look at the Moller rotary, you could write down an entire 
laundry list of design ideas used in that engine which are completely 
new and different from anything anyone has ever tried with these 
engines before.
	You simply are never going to find a piston engine as different 
from any piston engine that has come before as these two rotaries are 
different from any rotary that has come before.  Piston engine 
technology has matured too much.  Rotary technology is still 
relatively new, and there are still many untried ideas.
	Which is not to say that I think in 10 or 15 years that there will 
be a huge turning of the tables and that we will all be driving 
rotaries in the future.  I think that very unlikely.  But I do think 
it likely that they will still be around, and that distinctions 
between them and piston engines in terms of emissions and fuel 
consumption, the obvious weak points now, will be dramatically less.

> They are still neat!  But then, I love just about every type of engine made!

 Me too.

Z