CUT

Hi, Paul....I failed to explain the test method we used to evaluate the
VG's.  First, we cut the VG's to length (aluminum stringer angle material)
and marked the bottom of the fuselage with Magic Marker where they would be
attached. We pre-drilled 3 holes in each VG and into the bottom of the
fuselage for the 1/8" rivets.  I then took off and flew the first flight
without the VG's and recorded the above temps. I landed, and while one guy
held the VG's in place, my brother (on a mechanic's creeper) quickly riveted
them in place. I stayed in the aircraft on the taxiway.  I was airborne
again less than 10 minutes after landing. I then recorded the second set of
numbers. I made an honest effort to keep the aircraft climbing at the same
airspeeds and rate of climb on both tests.  The only variable I could not
control was that the engine/cowling was heat soaked right after the first
flight (without VG's), so temps at takeoff were a little higher on the
second flight (with VG's) due to heat soak and taxi time. However, the temps
on the second flight were much lower than the first flight.
    Yesterday, the radio said the Mobile temps were 91 degrees, so I
decided to play hookey and see how it worked on a hot day, and rushed out to
the airport. When I took the active runway, the OAT was 90 degrees.  Here
are the numbers I observed...
       OAT 90 degrees F
      Water temp on Climbout.......190F
      Water temp level, WOT........181F  (3000' AGL)
      Water temp level, cruise........173F  (3000'AGL)
       Highest oil temp...................182F

   I flew it again today and observed the following numbers...
   OAT 85 degrees F
   Water temp on climb out.........190F
   Water temp level, WOT.........180F  (3000'AGL)
   Water temp cruise..................172F  (3000'AGL)
    Highest oil temp....................180F

Not sure why, but very little difference in temps for the two days.  I have
not had temps like this since flying it in the winter, so something is
working. I cannot explain why it works....I can only provide the data
observed following the VG installation. (Just my conclusion, based on temps
only).  Take care.  Paul, love my rotary, Conner


Totally amazing repeatability for widely different ambient temps.
Are you sure some instruments are not stuck someplace? :)

The last pieces of the puzzle are a few numbers.
Climb rate?
Test gross weight?
Top speed.
Size of the radiator core?
Stock Mazda oil cooler. Yes or no?
EGT's?
Mixture monitor readings if you have one?

BTW keep flying those hours off. Hope to see your airplane
at OSH.

Paul Lamar

Hi, Paul....I don't think the temps are off, as I have two temp senders and
two temp gages. I have the MicroTech ECU with the handheld programmer which
displays the temps (on the handheld programmer which is actually mounted on
the instrument panel). It is connected to the stock Mazda water temp sender
located on top of the water pump. I also have an engine monitor which is
connected to another stock Mazda water temp sender which I located about 1/2
inch away from the original Mazda sender. Readings on both are always the
same (or at least within a degree of each other).

I will try to answer some of the questions.

Climb rate ....I regulate climb by airspeed, but most of the time it climbs
between 1200 and 1500 fpm up to 5000 AGL.  Don't really know about climb
rates above that, because most of my flights have been 5000 AGL or less.

Test gross weight....My aircraft empty weight is 1154 lbs. I weigh 205 and
had 30 gallons of fuel onboard. (70 gallon capacity). 1154 lb. aircraft
empty weight includes oil, coolant, headsets, etc, including everything but
pilot and fuel.

Top Speed....top speed for these tests was only 150 knots, (in level flight)
as I did not retract the nosewheel. I wanted to see what the worse case
scenario temps would be (ie...unable to retract nosewheel, etc).  Obviously
temps would have been a little better if I had retracted the nosewheel and
let it build up some speed.  I also conducted my climb tests at VX with the
nosewheel still deployed.  Under normal circumstances, I would retract the
nosewheel soon after rotation, so climb speeds would increase somewhat
because of the decreased drag caused by nosewheel retraction. I have flown
the aircraft with the nosewheel retracted, prior to conducting the VG
cooling tests, but wanted to see what my temps would be like without
retracting the nosewheel.  On the next flight, I will retract the nosewheel
and record those numbers.  Certaintly shouldn't hurt my numbers any by
retracting the nosewheel.

Size of the radiator core....Please don't hold me to these numbers, as I am
going from memory, (and that was the first thing to go)...I had the radiator
custom made by C&R Racing to fit behind my cooling duct. (with added
extensions).  I believe the actual fin area is approximately 14" x 10" x 3"
thick.

Yes, I have the stock Mazda oil cooler.

EGT's....I am a little embarrased here...My AV-10 engine monitor displays
the EGT, but I have to scroll thru several pages of information to pull it
up, and I normally have my engine monitor showing engine rpm, prop rpm and
water and oil temps.  On previous flights (prior to the addition of the
VG's), I have occasionally scrolled to the EGT page, and noted that in
cruise the EGT's were 1400 to 1450 depending upon throttle setting.  My
AV-10 engine monitor has an additonal 4-line display on which I can display
different user selected engine parameters....unfortunately (the embarrasing
part) I haven't taken the time to do this yet. (select which parameters are
displayed on the optional 4-line display).  So, unfortunately that's all the
EGT data I can share. My EGT probe is located in the first 1 inch of the
short (8 inch) tailpipe extending from the stock Mazda cast iron exhaust
manifold.

Mixture monitor readings....another embarassment....(Stop embarassing me,
Paul)....The MicroTech ECU I believe on page 30 shows air fuel mixture.
Haven't paid much attention to it yet.   Now that I can fly around and not
worry about temps, I will start "spreading my wings" and investigating
EGT's, fuel/air mixture ratios, fuel consumption, high altitude temps/cruise
speeds, etc.  I was really slowed down by my early engine failure  (caused
by vapor lock), then finding that my engine never really ran the way it
should because I had hooked both my engine monitor and the ECU to the same
water temp sender, (which gave erroneous info to the ECU)  but now that I
have addressed those problems, and the engine runs like a swiss watch, no
more fear of vapor lock, and water and oil temps where I want them, I plan
on flying a lot more and learning more about the aircraft and it's systems.

Hopefully, I can now contribute to this forum instead  of just asking asking
a bunch of (sometimes dumb) questions (as I have done over  the past two
years while building).

Paul...Thanks for sharing my rotary experience with others... I hope it's
helpful to someone. (anyone)?  I am so pleased that I chose the rotary
engine for a powerplant. I don't have the fear of a $12,000.00 engine
overhaul, or some AD popping up to haunt me.   Paul, I love my rotary,
Conner


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