I *FINALLY* get to send this email...


 3/17/2010 - 10:46 AM MDT
 K00V - Meadow Lakes Airport, Peyton CO
 OAT:   50F
 Winds: 5kt out of north
 Field Elevation: 6875
 Density Altitude: 7680
 Mazda 13B rotary, NA with Peripheral Porting
 2.85:1 redrive, standard prop rotation

 Mustang II N512SR leapt into a blue Colorado sky from runway 33 like a
 bat out of hell (no homesick angels here).  Takeoff roll was 1500 feet
 max; tough to tell from our vantage point at the ~3000 foot point of
 the 6000 foot runway.  At the controls was our test pilot Bill
 Mitchell (2008 EAA AirVenture Spirit of Flight Award winner for flight
 testing).  Climb out was max-performance at 85 indicated.  (Appx
 1000fpm indicated)  Aircraft was climbing through pattern elevation by
 the end of the runway.

 Bill departed the pattern and took the airplane east of the field to
 10,000 feet.  Water temps throughout the climb were a chilly 178F max.
  Oil temps were not as kind, 197F on takeoff, 217F when departing the
 pattern, and 241F at 10,000 feet.  Oil temps quickly dropped back to
 215F on level out, but none the less are a source of concern.  We'll
 see if a less aggressive pitch angle on takeoff (and hence a faster
 IAS during the climbout) helps the oil temps during  the next flight.
 If not we'll have to start looking at what we need to reconfigure.
 For this flight, they were what they were -- Bill had to get enough
 maneuvers in be able to safely land again, so once around the patch
 and land again was not in the cards.  The quick drop back to 215F on
 level out made everyone feel better.

 Bill put the airplane through is paces for basic flight
 maneuverability.  He reports the airplane flies hands-off straight and
 level when properly trimmed there is no 'heavy' wing behavior.
 Power off stalls (clean) broke smartly and evenly at 64 indicated.
 Relieving the back pressure on the stick resulted in almost no loss of
 altitude during the stall.  Dirty stalls at all flap settings
 similarly broke smartly and evenly at 62 indicated.  Power on stalls
 broke quickly/aggressively at the same 64 indicated.  There is little
 or no buffeting prior to any stalls the airplane was completely
 controllable at 65 indicated before stalling at 64.

 We did have an issue of all things with the pilot seat locking
 mechanism.  As a former Cessna test pilot Bill warned before the
 flight that we were likely to find the locking mechanism did not stay
 engaged.  He was proved correct in flight and was not able to get the
 seat to firmly stay in place.  This cut short 1st flight since Bill
 was not able to have full rudder authority with the seat sliding
 backward.  Bill is not a tall fellow, and was only able to get ½ of
 typical rudder motions with the seat in the aft position.

 Bill reports the engine performed flawlessly throughout all phases of
 the flight.  He was comfortable enough with its behavior to do things
 like the above mentioned power on/off stalls during 1st flight.  The
 engine responded promptly to all throttle commands.  Very smooth in
 operation at all rpms, and he was easily able to detect on final when
 the prop went from producing forward power to windmilling & creating
 drag as he throttled back.  Maximum rpm (that he noticed) was around
 7000 (~2450 prop).  Given that our prop is only a 68x68, we would
 expect to be able to get to the electronics limit of 8000; it would be
 surprising if the engine could not do better than 7000 at cruise / max
 speed that will have to be a test for another day.  Bill's comment
 at the end was that  the only smoother engine would have been an
 electric motor but finding an extension cord long enough is tough
 He was pleased/impressed and had no engine related squawks (other than
 oil temp during climb).  From the ground the engine sounded fantastic.
  Very smooth, and really a quite pleasant note.  I've said before that
 no one can accuse my engine of being quiet on the ground, but even the
 local A&P who was watching the festivities from  his FBO commented
 that it sounded nice & surprisingly quiet on takeoff.  Who'da thunk
 it...

 Removing the cowl after the flight revealed... nothing.  Everything
 looked great with no signs of anything amiss.  We'll be doing some
 more disassembly and inspection before the next flight to make sure
 everything is hunkey-dorey.

 Terry and I both extend our heartfelt thanks to Paul Lamar, and the
 rotary aviation group.  Without Paul's  over and above assistance,
 including 2 trips to Colorado Springs to inspect the install & a 1200
 mile road trip to pick up an ailing engine in the middle of Utah we
 would certainly never have gotten to 1st flight, much less a first
 flight that was entirely uneventful from an engine perspective.  (You
 haven't lived until you've driven 600 miles in the middle of a Utah
 summer, parked by the side of the highway in the literal middle of
 nowhere, and erected a shop crane to hoist a 13b out of 1 minivan and
 into another, followed by a 600 mile trip home).

 Mark & Terry (Rocky Mtn High)

 ** Mark Steitle, would you please take some good pics of your dual oil
 coolers & how they are mounted?  If ours isn't going to cut it, I was
 liking the looks of yours when you came for a visit last summer.  We
 should have no problems implementing your style setup (which is known
 to work).

 I am relieved finally! Thanks to all the guys at Mazdatrix for building
 a great engine.

 Paul Lamar



 Mark,

Way to go!!!  Its been a long time coming.  My oil temps were up into that
range on my first flight and I just went around the patch once and landed.
 Glad things went so perfectly for you.

Regarding my high oil temps, it took me a while, but I discovered that I had
a defective oil cooler that was allowing the oil to bypass the core.  Once I
replaced it with a new oil cooler I was able to remove the oil/water
exchanger.  Since you're running a p-port, your horsepower is higher than a
regular side port 13b, so unless you used a 13B-REW oil cooler, it may not
be up to the task.  I also discovered that Lynn Hanover was right on the
money in that you'll get more horsepower out of the engine if you can keep
the oil temps down around 160*.  While installing an oil/water exchanger did
get my oil temps down some, all it really did was to transfer the heat from
the oil to the water.  It still has to be transferred to the air sooner or
later... better sooner.  So, I would recommend improving the airflow through
the oil cooler (possibly a larger exit duct), or installing a larger (or
more efficient) oil cooler.

Mark S.
Austin

Right on Mark.

Paul Lamar