X-Mozilla-Keys:                                                                                 

BTW I forgot to mention that the resultant power to
weight ratio based on a 13B dry weight of 230 pounds
with PSRU and 240 HP of 1.05 HP per pound would wip
the heck out of any piston aircraft engine available today.

If it were not for the liquid cooling system that
would be true.

If you add another 40 pounds for the liquid cooling system
you obtain a total weight of about 280 pounds and you
get a power to weight ratio of 0.85 which still wips any
available piston aircraft engine by a bunch.

Take a look at the 407 pound weight of the popular 250 HP
Lycoming IO-540 in the chart I just uploaded.

Paul Lamar

Bill Freeman wrote:

Sounds really nice Paul, and no doubt it may even be
possible.  Has any ACTUAL installation come even
close to std AC motors power to weight?  I don't
know the answer, this is not a loaded question.  Seems like
the numbers I have heard indicate about a 30-50% wt
penalty on the FWF assy for current rotaries vs actual
AC installations.   Am I missing out on someone's
super light installation?

No intent to defame, and I DO understand that a lot of the
existing installations are admittedly not optimized for weight,
but are valiantly solving serious issues and putting their butts
on the line to do it.  I do not underestimate their efforts,
but it seems we owe the newbies  a commitment to
report what has actually **been done**, not what we believe
can be done.  Many AC are real dogs if saddled with an
additional 50-150 lbs beyond the designer's intent.  My
guess is that most of us are not patient enough to build a
*really* light installation.  It is way too easy to use the heavier
parts, and cheaper, too.  I don't hold myself above this, but
 I try to work towards Rutan's "simplicate and add lightness".

Bill

Yes I think you are missing something Bill. 
Tracy Crook's installed weight is about the same as an O-360 
Lycoming and only has about 180 HP. This despite the 
fact his engine mount is about 19 pounds heavier than it need be.

Allan Tolle was sweating an aft CG problem on his 200 HP Power Sport
installation in his RV. Rads were under the cowl. He suggested
making a new cowl and moving the rotary engine forward.

As I pointed out with peripheral ports 240 HP NA is possible
which allows the engine to replace a much much heavier O-540.

You are right. Some people don't pay enough attention to
small things and they add up. I won't mention names but you
people KNOW WHO YOU ARE!!!!! :-)

Paul Lamar
 
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