Hi  Paul.

     1)  Aside  from   perceived  poor  fuel  economy  of  rotary
    engines, what  are  its  disadvantages ?

     2)  You  advised  carbs  and  magnetos.    Why  are  they  not  discussed
     here?
     Are  they  not  suitable  for  rotaries ?   If  suitable,   Let's
   have  more  discussions.

     3)  Can  there  be  carb  icing  in  tropical  countries  below  3,
   000 feet ?

     Best regards.
     Ben

     Fuel economy is only 5% higher than an aircraft piston engine.
   This is more than made  up for by the 25% lower cost of auto gas.

     Magnetos are suitable. They will work fine.  They are just too costly.
    $2000 each new
     and $400 to $800 re manufactured plus cores. People don't want to
   pay as much for two  aircraft magnetos as they pay for the rest of
   the engine. In some case much more than  they payed for the engine.
   RX8 ignition coils are $25 each for a total of $100. One  coil per plug.

     However if I were certifying a rotary I would use aircraft magnetos
     and an aircraft carb. The FAA is much more comfortable with that they
    they are with
     EFI and electronic ignition. In that case the rotary engine would pass
    certification
     in a heart beat.

     The best carb (cost verses power) to use is a two barrel 500 CFM Holley
    with a
     leaning kit.

     The FAA will not sign off on your carb engine unless it has carb heat.

     Paul Lamar

    Thanks  Paul.

    I'm  glad  there  is  someone  like  you  who
    has  the  knowledge  and  patience  to  answer
    our  questions.

    Can  there  be  carb  icing  in  tropical  countries  at  an
   altitude  up  to 4,000 feet ?

     Best regards.
     Ben

    At the higher altitudes for sure. The evaporation of the fuel in
   the carb venturi causes a cooling effect.

    Paul Lamar

   Paul,
   My Continental IO 520D has fuel injection- but it is a very basic system
   indeed. One inj per cyl, a regulator, and a mechanical "TPS". It
   looks like it all related back to the manual leaning valve and quite
   possibly the manifold pressure. This system seems remarkably like
   the old FI on the corvettes in the early 60s. Regulators and manual
   flow metering.

   Why would this be a difficult system for the rotary? Before I sell my
   Connie, I might inventory the system and see about maybe a prototype.

   Kevin Alderman

   http://www.vette-vues.com/parts_for_sale.html

   Early Power Sport used mech fuel injection.
   It is still sold for aircraft.
   http://www.airflowperformance.com/html/site_html.html

   Paul Lamar


    These early Rochester FI systems were not received well due to a couple of
 things. The dual quad made more power the next year and the injection was very
 sensitive to atmospheric conditions. It required almost daily tuning unless
 someone really knowledgeable worked on it.
    Att 1.  The "throttle" in the center is not the throttle. It is the choke
 plate.  The throttle can be more easily seen in Att 4.
    This works similar to the Bosch/Volkswagon FI and the Mazda MCES systems,
 that use a special volute and flapper to measure air flow. The Rochester used
 the cone in the intake to create a pressure drop like a venturi. This was fed
 over to the diaphragm to lift the metering "rod" to add fuel. At idle there
 would be no "vacuum" on the sensing line. As the throttle is depressed, the
 air flow causes a vacuum at the venturi and lifts the diaphragm. Different air
 densities and humidity affected the fuel required which was not well
 compensated for. The Mazda MCES works fairly well as the sensor is a form of
 mass flow and is compensated with the computer. The Bosch also works as a
 basic mass meter, but did not have a computer (Rabbit system. different from
 K-jetronic).
    Any AC system will have compensation for atmospheric condition as a
 requirement for altitude changes.

 Dale Davies



      Hi   Paul,
                      No FI system I have ever flown with has allowance for
 temperature or density, only have experience with Cont and Lyc. My understanding is
 they are both a engine speed/throttle/mixture position, ie if you have the
 mixture,prop,throttle to the wall you will always get the same fuel flow, regardless
 of temperature and,or altitude. But I love 'em, no carby icing!! BUT if you have
 clogged injectors your fuel flow gauge will tell you you have say 36 gallons pre hour
 at take-off, you will have something less than that, because it is not a fuel flow
 meter but purely a pressure gauge! calibrated to indicate fuel flow in gallons per
 hour. Where it become bad is if you have only one injector, you may not notice the
 fuel flow is lower than it should be for that engine, unless you have  EGT probes in
 each exhaust outlet.
      John Burey


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