> > > > I am 90% done with the airframe of my dragon
    > fly I
    > > >
    > > > am intending to
    > > >
    > > > > power it
    > > > > with a 13b. Any comments? Anyone seen a rotary
    > > >
    > > > powered dragonfly?
    > > >
    > > > > would make
    > > > > quite a buzzz.....
    > > > > --
    > > > > Thanks,
    > > > > Brent Hasty
    > > > >
    > > > > Isn't it a bit heavy Brent?
    > > > >
    > > > > Paul Lamar
    >
    > --------------------------------------------------
    > vw engines are around 165 lb average see:
    > http://www.greatplainsas.com/specsfd.html
    >
    > I initially began to think about repowering with a
    > rotary when on the list
    > someone sent out a link to an outfit making
    > alumininum side plates, this
    > makes it around just 50lbs heavier than a vw for
    > well over twice the hp, not
    > to mention reliability issues...
    > What are other means to put a 13b on a diet, if one
    > were willing to sacrifice
    > a little bit of horse power?
    >
    > I do not think a rotary powered dragonfly is
    > insurmountable.
    >
    > ------------------------------------------------
    >
    > > > I'd think so.. I just about bought a Dragonfly
    > > > project, but was
    > > > discouraged by the weight limit for an engine,
    > and
    > > > who wants to
    > > > fly behind a VW motor?.. If memory serves me
    > > > correct, a c-85 was
    > > > to much weight. A single rotor would fit, but
    > that
    > > > might mean a
    > > > bit of a wait until they get on the market..
    > > >
    > > > Jarrett
    >
   --------------------------------------------------------------
    > What are the dynamics of aircraft performance that
    > are affected by a engine
    > weight increase like I am discussing?
    >
    > Consider the reduction of stall by modifying the
    > Aelerons with a flaperon
    > mechanism similar to the kitfox and avid?
    >
   ---------------------------------------------------------------
    >
    > > I owned and flew a Dragonfly for many years.  The
    > 13B
    > > is too heavy and powerful for that design.
    >
    > -------------------------------------------
    > How can one ever have too much power?
    > -----------------------------------------
    > >It was
    > > designed around a 1600cc vw, but others have
    > installed
    > > c-85/O-200, Jabiru, Subaru, etc, up to about
    > 135hp.
    > > Mine was powered by the humble VW for 240 hrs or
    > so,
    > > then switched over to a turbocharged Subaru EA81.
    > > Performance increased significantly, and no more
    > 50 hr
    > > valve jobs req'd.
    >
    >
   -------------------------------------------------------------
    > At 200lbs the weight of a 13b-aluminum is equal to
    > the ea81 with significantly
    > more power.
    >
    > Any clue the VNE of the dragonfly airframe? (cant
    > find it on google)
    >
    >
   ------------------------------------------------------------
    >
    > > There was one fellow out near Mojave somewhere
    > that
    > > had built a single-rotor powerplant for the DF.  I
    > > visited his hangar back in the mid-90's.  I have
    > no
    > > idea if it ever flew with that engine.
    >
    >
   -------------------------------------------------------------
    > I have a farm I bought to put a fabricaton shop on
    > that is 2500 feet long, I
    > hope to be able to get in and out with the
    > dragonfly.
    >
    > The extra power will help to leap off the ground,
    > but I will have to deal with
    > a hot landing......  Again the flaperon idea may
    > help.
    >
    >
    >
    > Thanks,
    > Brent Hasty
    >

   Brent,

   Vne on the Dragonfly is 180 mph.  Clean examples can
   already hit 160mph with a VW.  A proper 13B would have
   at least 3x the power of the VW, but would be of very
   limited use in that airframe.

   My EA81T setup weight 215 lbs wet, firewall forward
   less prop.  This included oil, coolant, rad, etc.  I'm
   sure an aluminum 13B would save significant weight,
   but would still be far heavier than a typical O-200,
   which is considered max for this aircraft.  Also
   consider the aluminum 13B engine cost would likely
   exceed the total value of the aircraft.

   Roger.


   The housings run $1500 each or $4500 for the set.
   The rest of the parts can be had for less than $2000 new.
   So you are looking at $6000 for the motor. Add $3000 for the
   PSRU. $9000 total is a far cry from the cost of an overhauled
   O-200 if you can find one that does not have a bunch of
   hours on at least some of its parts. There are no new O-200's.
   Also the rotary is now far far cheaper to overhaul.

   The 100 HP O-200 weighs 170 pounds. Add another 30 to 40 pounds for
   the stuff you need firewall forward and you are not that far
   off from the 260 pounds firewall forward for an all aluminum
   13B rotary.

   No question if you just want to fly putting a used O-200
   (they are all used) in is the easier way to go. Takes less time.
   The cost is about the same. However where is the  creativity
   and challenge in that? The rotary will be much smoother
   and less fatiguing to fly long distances.

   Excess HP is best used in an airplane to enhance the take
   off and climb. Particularly at high altitude airports where the
   power is down to 75% or less of sea level power. Out here in the
   west we have 10,000 to 14,000 foot mountains to fly over.

   The top speed is proportional to the cube root of the HP. The rest
   of the time you can throttle back and not use the HP.

   Paul Lamar ...No rotor no motor.



TCM makes new O-200's..

http://tcmlink.com/engines/index.cfm?lsa=yes

They're putting them in the Cub clones..



Matt-

I learn something every day. I did not know that.
Neat little engine. How much Matt?