Paul,

  Can you make sense of this posting... and how it compares to
the fuel burn
  of the rotary?

  Mark S.

  ----------------------------------------------------------------
  I have seen different conversions of fuel burned to horsepower
generated
 so
  I went back to the GAMI wizards for the details.
  John-Paul said:

  Typically, the 8.5:1 compression ration engines use 14.9
hp/gph while
  the 7.5:1 CR engines use 13.7 hp/gph.
  The TSIO-550-E engines use 24° BTDC timing and are a little
more efficient
  that the typical 7.5:1 CR engines, though.
  George speculates ~14.6 hp/gph.  Looking at the operation
manual, it looks
  more like 14.75 hp/gph. <<<

  So there ya' go. Take your pick.

  Robert M. Simon
  ES-P N301ES
  ----------------------------------------------------------

  Nothing like using a non standard fuel burn number to
  bamboozle your customers. hp/gph :) Gami has been at this
  misleading stuff for years.  All designed to sell
  matched mechanical fuel injection injector orifices.

  It is something hard to prove as nobody knows how much
  HP their engine is really developing while in the air.
  That is why I harp so often on built in torque meters.

  BSFC not hp/gph is the world wide standard.
  BSFC means Brake Specific Fuel Consumption given
  in pounds of fuel burned per HP generated per hour.
  Weight of fuel is used for a good reason. The energy
  derived is a direct function of the weight of fuel
  burned and not the volume of fuel burned.

  1 gallon an hour is 6.25 pounds of fuel an hour
  at some standard temperature.

  This volume number varies widely with temperature
  so take claimed BSFC or hp/gph with a grain of salt.

  6.25 pounds of fuel for 14.9 HP for one hour is a BSFC
  of .42. Possible but unlikely.  The best numbers
  I have seen are more like .45.

  The current rotary, properly
  leaned, is .47. Mazda claims a breakthrough for
  the 16X. That could be as low as .41 to.43 when
  it appears is my guess. Diesels are typically .38.
  The R3350 turbo compound got down to .34 or .35
  at 20,000 feet or so.

  Cessna claims my C182 with a Cont. O-470 carb is
  .5 BSFC or so as I recall. The EGT's and CHT's are
  all over the lot. It burns 11 to 12 gallons
  an hour at 8000 feet and about 150 MPH.

  What kind of cruise numbers are you seeing
  and what are the EGT's?

  Paul Lamar

 Paul,
 With my old side port motor I would typically see 158 - 160 kts
 TAS.  It would go faster, but the 158-160 kts number was in
 "economy cruise" at WOT and 1700 rpm prop setting, 11.4 ghp.  I
 got it up to 203mph a time or two, at 6500 rpm, burning a lot
 more fuel too.

 The new p-port motor results in an "economy cruise" of
 173-174 kts [199 MPH] TAS at WOT, 1800 prop rpm.

 Picture is from a recent
 flight from Galveston (KGSL) to Lockhart (50R) at WOT, prop set
 to 2000 rpm.  It shows 209 mph TAS, 8500 MSL.  (Don't pay too
 much attention to fuel burn as the EM-2 fuel calibration is not
 correct.  The oil temp shown is measured after cooler #1 and
 before cooler #2.  OIL TEMP after cooler #2 was w/i 1* of
 coolant.)

 Top speed to date is 213 mph, but is still TBD as I'm still
 tuning the EC-2.  I removed and returned my EC-2 to have it
 converted back to old-style CAS.  (Yes, after fighting it for 3
 years, I gave up on using the Renesis style CAS.) I'm currently
 running Bob Darrah's EC-2 which is configured for the original
 20B CAS.  So, tuning was all wrong (for my engine).  Hope to
 find a few more mph through tuning; upper MAP addresses are too
 lean.

 Mark

 When is the next fly in in that neck of the woods? Robin and I
might fly
 down. I need some more pictures of your p-port 3 rotor engine.


 Paul Lamar

Paul,

Nothing "rotary" scheduled that I'm aware of.  Although I am a
regular at the local fly-ins.  (Gotta educate the masses!)

I've got quite a few pictures that I can send you.

 Mark

Just a good local fly in will do. Probably a couple of rotaries
will show up. I would like to explore the Texas gulf coast.
Never been there.

OK send away on the pictures. Don't worry about the size.
I can handle them.

-----------------------------------------------

I just found that Cessna 182 O-470 BSFC chart I knew I had
somewhere. Here it is. The compression ratio is 7:1.
My new engine is 8:1 and needs 100 LL only so the BSFC
should be a bit better.

Paul Lamar