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,

 As a "fan" of ducted fans for use in Hovercrafts and Air Boats and some
 other applications where it seems like everyone in those markets or a
 majority use ducted fans.

 I have a question for you as you have a strong opinion (with data to
 support) that the drag of the fan blades outweighs the thrust benefits.

 What if one was to use a duct with a two or three blade prop what are the
 advantages or disadvantages of this combination use?

 Thanks Paul for any input you can provide me regarding this.

 Eric Barger

 The number of blades has no relevance.

 Air boats are in a different speed range. Apples and oranges.
 In that case static thrust is everything. Ducts are good.

 Here is one I got a ride on. No ducts :) Exception to the rule.
 I am so sad this is not still around. I did ride a smaller
 one not too long ago in 2005 Ryde and Southsea.
 http://www.hovertravel.co.uk/

 Paul Lamar

I think this big craft may be on care & maintainance for
possible military or other logistic use.
Fly & build good -
Mr Bryan Wilkinson in England


The US Marines are using similar craft.

I have had rides on two out of these three? :)

Paul Lamar