> > >>> Wouldn't it be wonderful if everybody developing an engine for use
> > >>> in aircraft could afford a dyno. It would be a lot safer if people
> > >>> tested their intended engine for horsepower on the ground
instead of
> > >>> during the first flight. It would also verify or discredit some of
> > the
> > >>> claims made by vendors selling auto engines for aircraft use.
> > >>> All too frequently they claim xxx HP at 6500 RPM and then install
> > >>> a 1.4:1 PSRU.
> > >>>
> > >>> http://www.youtube.com/watch?v=sImSPvPglbI
> > >>>
> > >>> The History Channel had a well done video segment on HP so
> > >>> I incorporated some of that. They asked a bunch of people; "What
> > >>> is HP?" and few could answer. It is amazing how many people
> > >>> still do not understand HP.
> > >>>
> > >>> There are good pictures of Ken Welters rotary powered Coot and
> > >>> Power Sports rotary engine prop dyno.
> > >>>
> > >>>
> > >>> Please give it the highest rating as that encourages other people
> > to view
> > >>> the video. The more rotary powered cars out there the better. This
> > >>> insures
> > >>> a future
> > >>> supply of the rotary engines, that we all know and love, for
use in
> > our
> > >>> aircraft.
> > >>> --
> > >>> Paul Lamar ...No rotor no motor.
> >
> > Paul, your suggestion regarding dyno testing rotary aircraft engines
> > with reduction gear installed would be a major advance for flight
safety.
> > This is the dyno we built in 1990 to test both rotary and Lycoming
> > engines. Phillip Groelz and I earlier discussed providing it for a
> > free/cost only testing service when people have fully assembled their
> > rotary engines. Would you be interested in being the dyno master if we
> > did this so there would be a good consolidated data base regarding
> > component development, service issues, sound, and performance?
> >
> > You may have seen the dyno when you were at the shop years ago. It
> > is basic and simple, using a torque arm connected to a rotary scale.
> > Uses the same principle as your drawing. We later added a pre-oiling
> > feature prior to startup. We discovered quickly that a shock absorber
> > for the torque arm was required for Lycomings due to the violent
shaking
> > on startup/shutdown. For rotary engine testing, heat exchangers were
> > installed along the back on top in the prop blast.
> >
> > The dyno instrumentation is old school so that would take two guys
to do
> > power runs....one to run it and the other to log the numbers during
> > runs. Be good to have modern data acquisition if possible
> > cost-wise. That area is your expertise. Phillip talked to Rob Hickman,
> > the owner/designer of Advance Flight Systems who lives next door and
> > would work with us. His system records the data. We talked to Rob
> > earlier about doing one for the rotary RV-3 being built and considering
> > using it on the dyno to gather data. But if we were doing a lot of
> > engines we would want to have something dedicated to the dyno.
> >
> > One of the major design considerations would be noise containment
> > provisions because the shop/hangar is at an airpark. An advantage is
> > that guys could fly in. We are about 7 miles from Van's Aircraft at
> > Aurora.
> > If we did this, seems as though we would want to use a variant of your
> > S-beam mounts to take just all 2 rotor engines. Would take a separate
> > mount for three rotor engines to put test club in proper location in
> > shroud.
> >
---------------------------------------------------------------------------
> > Related background:
> > During the years we worked on the prototype rotary aircraft engines
> > using this dyno, it was stunning the number of things that broke during
> > testing before the engine ever got into flight tests. We learned a lot
> > about what would crack or break--exhaust pipes and mufflers, accessory
> > mounting brackets , throttle shafts, oiling issues, ,engine mount
> > tubes,drive belt harmonics and on and on. Granted the issues we faced
> > were greater because these early prototypes engines used many
> > original components and combinations.
> >
> > Prior to constructing this dyno we ran the first Superlight rotary
> > aircraft engine in 1988 on the shop water brake dyno used for race car
> > and boat engines. Not good for the geared rotary engine because
> > without the propeller it did not provide the complete torsional
> > equation. Raised all kinds of hell with breaking input shafts,
> > reduction gear and pieces inside and outside the engine. The test
> > club shown here is the one we use for both Lycomings and rotary
> > engines. It started life as our first rotary engine propeller---84"
> > dia. and and high pitch. During early flight tests we lost a
> > stationary and internal rotor gear, and subsequently delaminated a tip
> > following the instant engine seizure. Cut down it maked a great test
> > club.
> >
-----------------------------------------------------------------------------
> >
> > Steve Beckham
> >
> > Very interesting Steve. Thanks for sending that picture and background
> > info.
> >
> > Yes I think it is the same one in the second picture here that I
took in
> > your shop.
> > Your dyno inspired me to build mine.
> >
> > Did you ever try it back to back with and without the stator?
> >
> > Here at Santa Paula the sound is not an issue as we can tow our
prop dyno
> > mounted on a trailer out to the far reaches of the field and it
makes no
> > more noise than
> > a plane taking off. Also as long as you stay out of the plain of
the prop
> > a safety
> > shroud is unnecessary. No more dangerous than running up an aircraft
> > engine before takeoff.
> >
> > You guys were the pioneers. Now ten years later we have dozens of
aircraft
> > flying with
> > many many hours using either the Ross gear box or Tracy's gear box
with no
> > problems.
> > Some are using the latest six pinion Ford based auto tranny
plantaries on
> > three rotor engines.
> > The secret is the torque pulse isolators.
> >
> > Paul Lamar ...No rotor no motor.
> >
>
>
> Thanks Paul.
> As to your points--
>
> 1. Running the dyno with and without the stator?
> We ran the first engine on the dyno (a Lycoming) without the turning vane
> assembly--had not built it and didn't know we needed it. But found
the prop
> blast exerted on the cylinders and evidently that long torque arm were
> obviously skewing the torque readings significantly and as I remember a
> significant improvement with cylinder cooling. Also the center blanking
> plate(s) were used to adjust prop load/ rpm range for various
engines--see
> photo--using same test club. This included the engine we built for Dan
> Denny's GlasAir III, a modified IO-540 . But if per your suggestion
we can
> make it work accurately without it, we should be able to test both 2,
3 or
> even 4 rotor engines all with your same modified mount.
>
> 2. The note about noise is driven as much as exhaust and combined
> exhaust/prop/gears. We found it necessary to do run, after run, after
run.
> Even with a muffler, the combined noise is a consideration in an airpark.
> On engines tested before Mazda developed its port inserts, the noise
without
> mufflers was, as you can imagine, brutal. It was problematic even
with the
> low restriction mufflers we were using at the time. Neighbors for miles
> would complain--and this was when we tested at the shop down on the farm.
> But I think this issue can be addressed. We could possibly keep the dyno
> down at the shop and test there but the logistics are a pain. And it
would
> be a disruption for Brent's operation there--he builds strictly
automotive
> and boats engines exception for some aircraft part component
machining, and
> balancing. And the airstrip has been allowed to deteriorate and closed.
>
> 3. Thanks for the photos of the rubber isolators. This is an approach
> similar to what we tested for our earliest planetary reduction drive. On
> subsequent planetary drive designs of various ratios using modified
> automotive gearsets we moved away from rubber isolators because we were
> shooting for something that would not be affected by heat, range of
motion,
> deterioration, cycling and ultimately were shooting for reduced parts
count.
> For gears, on the last SuperLight engine (see photo) we went away
from the
> Ford C-6 planetary-based parts used previously. On all the helical cut
> planetary gears, we found end-thrust a limiting factor for sustained
> high-output. Toasted end-thrust bearings. This problem was solved on the
> last planetary we did that is shown attached by incorporating
straight cut
> planets produced by Allison for truck applications (2.08:1). And by
then we
> had fully sorted out our pendulous dampers shown in this photo. It took a
> lot of design and fabrication work over two years but really did the
job. A
> photo of it on dyno attached. Apologize for lousy quality. It's scanned
> off an old snapshop I took.
>
> 4.Ultimately we went away from the planetary reduction design because
of our
> decision to do the lower cost Iron Eagle Mazda conversion engine. To
reduce
> consumer costs the design goals included a simple, torsionally stiff
gearset
> without having to use any isolators, friction dampers, pendulous
dampers or
> anything and one that would hold up under repeated misfires....basically
> using the propeller as the flywheel. That's why we went to an
internal spur
> gear. The photo enclosed shows a view of the last SuperLight engine with
> planetary reduction gear and the Iron Eagle with the internal spur
reduction
> gear. When I sold Powersport it was with the desire that this SuperLight
> engine be donated to the EAA Museum. Hopfully it was not cannibalized for
> parts. It was a neat piece and incorporated interesting stuff not
known to
> folks. It represented about 10 years of work. With the sale they also
> received our direct-drive, furnace brazed lightweight steel engine
not yet
> run.
>
> 5. Hope to see you at Marysville but it appears weather may be an
issue up
> here for mountains unless launch today.
>
> Steve Beckham

Mr. Beckham:

Your Superlight and Iron Eagle engines: GORGEOUS!  Works of Art!

"direct-drive, furnace brazed lightweight steel engine"?  What??
Please, tell all!

Thanks,

Les Nordman :-)

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