I'm just new on this list so pardon me if I'm breaking protocol or
 something, i'm not meaning to. I'm trying to contact Paul Lamar who I
 understand is the guru of all guru's in rotary engines. I'll give a little
 of my background, I'm old and was around during the time of the old radial
 engines, R4360's and R3350 turbo compounds and so on before the turbines
 and
 jets took over. The same thing didn't happen to small planes in general
 aviation but we do have the rotary engine that at least runs the same
 direction all the time unlike reciprocating technology. So anyway with
that
 said, here is my question and anyone is welcome to chime in. I love rotary
 engines and turbine engines, so I'm wanting to use one on one of my
planes,
 probably my little C-150 would be a great candidate since the little O-200
 is getting up in time. This is a multipart question by the way,

  1. What engine would be suitable for a C-150 conversion?
  2. Also has anyone heard of a ducted fan unit that can run directly
  on the rotary engine as to not require a PSRU/prop?
  3. What are the pros and cons to my probably rediculas question?
  4. I'm sure there are regulations somewhere to prevent this even if the
  parts were right in front of me, but I'm interested in looking into this
 at
  least.

 Thank you so much for any assistance or knowledge you can offer.

 Bruce

 I hate to be so negative but the FAA does not like people
 putting non certified engines in certified aircraft.
 It can be be done but the restrictions are many.
 The program is designed for engine manufacturers intending
 to certify the engine. Unless one is in that category
 it is near impossible.

 Ducted fans have been tried over and over again for decades
 all with the same bad results. Kuchmen & Weber summed
 up the problem in this graph. The drag of the duct outweighs
 the increase in thrust.


 Paul Lamar


Thank you, I appreciate the info. That makes sense too. Bummer though, I
was
hoping I would be able to get rid of the old Continental and replace it
with
a pistonless engine. :-)

By the way, what is the TBO on a 13b rotary and what is the approximate
expense of an OH just in case I find a home built with one?

Bruce

I don't think anybody really knows what the TBO is. Some guesses based
on iron apex seal wear is 3000 hours. Perhaps 2000 hours may
be more realistic. I don't think anyone has more than 2400 Hours.
Silicon Nitride apex seals wear at a much lower rate. E-shaft and rotor
do not fatigue. Main and rotor bearings last indefinitely at the
RPM we use in air craft applications. Keep it cool and keep it
supplied with clean oil and it will out last you :)

http://www.rotaryeng.net/Rotor-v-Piston.html


Paul Lamar

Paul, has anyone tried using the smaller "fan" without the enclosed
shrowd or duct? , Just like using a prop and use it direct dirve? I suppose
the tips speed has to be below sonic, I'm only guessing, but with that said,
does anyone have a spread sheet designed to calculate the max diameter of a
prop or fan at various rpms? I was going to make one but realized I don't
know that much about other variables such as altitude and pressure v. speed
of sound.

Bruce

Generally speaking the lower the diameter of the fan the lower
the efficiency in our speed ranges. Best keep them 68 inches minimum.

Paul Lamar