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Tracy,
Does the EC3 require any modification due
to coil change from stock?
Bryan
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Mark Steitle
Sent: Sunday, August 14, 2011 6:18
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 20B RV-8
altitude test results
Tracy,
Did you secretly swap out the 20B for a Renesis without telling anyone?
Those numbers look fantastic. They look like what I would expect to
see from a 2-rotor. Maybe I need to start flying higher. How do
they compare to your lower altitude numbers?
P.S. Can you provide the missing info for my spreadsheet?
Prop, mods, significant events
On Sun, Aug 14, 2011 at 4:12 PM, Tracy
<rwstracy@gmail.com> wrote:
Got the coils changed out from RX-8s to a mixture of LS2 and LS1 coils
and installed in an improved air box. Coils much cooler now.
Ran with auto pilot on to hold altitude steady during tests so I think
they are pretty accurate. I was mainly interested in fuel economy and
speed at various fuel flows. All these results were at 14,000 feet.
I'll do some at 18,000 where the results should look even better next
time. I forgot to dress warmer because the temp on ground was 94 F.
OAT during test was 39F. Speeds are TAS.
6.0 GPH 169 mph. 28.1 mpg
7.0 GPH. 180 mph. 25.7 mpg
8.0. GPH. 200 mph. 25 mpg
10.0 GPH. 224 mph. 22.4 mpg
The manifold pressures sounded a bit unrealistic during test but 2
different instruments agreed so I think they are right. The only one I
wrote down was at 7 GPH where it was at 13.9" Hg and rpm was 5174.
The sweet spot seems to be very close to 8.0 GPH. I think that is where
the rpm gets into the area where the fuel charge is stratified by the
centrifugal force at around 5400 rpm and the mixture can be aggressively
leaned.
The goal is to get 30 mpg at 200 MPH at 18000 ft. If I can get
there I can fly non stop from FL to CO with only a small aux fuel tank.
Who's flying one (P-ported *Renesis*), & does it meet *both*
criteria?
Clarification: If I read correctly, the question was about complex intake
vs adding a supercharger & using it to 'normalize' only back to the output
of a properly done intake. My point is that a manifold like Tracy's is very simple to build (much simpler
than anything for an aftermarket supercharger), and the power (and efficiency)
is there with much less weight & much higher reliability. Higher *output*
& high altitude benefits are still there, but that wasn't the question.
Obviously, after the P-port is done the intake is simpler (by 2 tubes), but not
that many homebuilders have the resources to do the P-port mod, which makes the
manifold look like child's play.
Charlie
On 08/14/2011 10:02 AM, Mark Steitle wrote:
Charlie,
Maybe you meant "...best power of all side ported rotaries".
I'm pretty sure that a p-ported 13B would easily produce more power than
a side port motor, assuming they do a good job on the intake and exhaust.
The nice thing about a p-port motor is the intake is simpler and easier
to build than a side port intake.
Mark S.
On Sun, Aug 14, 2011 at 8:34 AM, Charlie England <ceengland@bellsouth.net>
wrote:
On the subject of Renesis intake complexity, take a look at Tracy's intake (pic from
his web site).
<mime-attachment.jpg>
http://www.rotaryaviation.com/renesis_engine.htm
Can't get much simpler, & as far as I know, he has the best power
numbers and the best efficiency numbers of anyone flying. His intake tubes are
now longer than in this shot, but as you can see from the pic, adjusting tube
length (retuning) is pretty straightforward.
Charlie
On 08/14/2011 06:36 AM, Ed Anderson wrote:
Sam, As you find in this "hobby" there are
always trade offs. First, technically there is no reason you could not do
what you propose - however, you will add weight and complexity. A poor
intake affects both N/A and forced induction - its just with forced induction
you are paying in a different way to overcome any defficiencies in your
intake.
If going that route, I personally would prefer the
centrifugal type belt/gear driven blower over the roots type which has
historically had the poorest efficiency. On the other hand, if you are
not going to "boost" above ambient pressure - then I think I
would concentrate on getting a good N/A intake.
Good luck on your project whichever decision/approach you
take. Super and Turbo chargers have both been used successfully.
Sent: Sunday,
August 14, 2011 1:01 AM
Subject:
[FlyRotary] Renesis Question
I think my brain has had a meltdown: I am thinking about
"supernormalizing" the Renesis engine. Is this even possible. The
idea is to use a by-passable positive displacement type blower (roots
type...probably an eaton m90) fed to an intercooler that then sends air to the
engine. If my thinking is correct, and it probably isn't, this would eliminate
the complex N/A intake, while not over-boosting the Renesis engine. Also, the
supercharger being a positive displacement blower would in theory produce more
boost than is needed by the engine at all rpm levels, eliminating the
"peeky" torque of boosted engines. The excess (above standard intake)
pressure would be controlled via an automatic or manual waste-gate. Please
shoot my idea down if it is insane, but i would like some constructive
criticism if it is available.
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