If and when Mazda comes out with the RX9 it will be challenge
installing it in an airplane. Here are some 3D's I did. This is the
Big GT40 TC we used on the time to climb. Should be about 900 HP.
Enough to win at Reno.
It will get a lot easier if you move the engine 4 or 5 inches
further forward. You might have to add a P51 style strake ahead of
the rudder to restore the direction stability. Our pilot has not
mentioned a directionally stability problem yet with the TTC.
Everything after RX9-15 is 5 inches forward.
This is just rough at this point and I will do another exhaust
manifold to make it easier o get the motor mount tubes in there.
Paul Lamar
Paul,
This is a what if kind of question. The design and dimensions of
the RX9 engine is all there. Someone like Promaz in Australia (
Promaz.com.au
<http://Promaz.com.au> ) could make the housings, plates
and rotors. Designed for any accessories and water pump. Injector
placement etc.
why I'm asking? Efficiency every ounce possible turbo compound
clutched supercharger etc on pump gas. Maybe 3 rotor?
been thinking about a 400kt Carbon fiber plane forever and a day.
Design has made leaps and bounds over the last few years but power
plants are still lacking efficiency wise. Any reliability is out the
window with piston engines at that speed. Or the weight and complexity
makes it a no go.
Estimate around 20k for block and crank maybe less if their
interested in the project.
Kurt Emerson
Paul,
This is a what if kind of question. The design and dimensions of
the RX9 engine is all there. Someone like Promaz in Australia (
Promaz.com.au
<http://Promaz.com.au> ) could make the housings, plates
and rotors. Designed for any accessories and water pump. Injector
placement etc.
why I'm asking? Efficiency every ounce possible turbo compound
clutched supercharger etc on pump gas. Maybe 3 rotor?
been thinking about a 400kt Carbon fiber plane forever and a day.
Design has made leaps and bounds over the last few years but power
plants are still lacking efficiency wise. Any reliability is out the
window with piston engines at that speed. Or the weight and complexity
makes it a no go.
Estimate around 20k for block and crank maybe less if their
interested in the project.
Kurt Emerson
Well it would not be wise to make the parts for e-shaft, rotor and
rotor housings. These are tried
and true with thousands of hours. The end and center housings for
the RX8 is another matter.
Since the RX9 is all aluminum even these parts will not have to be
made.
The speed is going to be a function of the frontal area of the
craft. That in turn will
be a function of how many passengers you would like to carry. One
pilot and one
passenger can be accommodated in a semi reclining position with the
lowest possible
frontal area.
My guess is a 3 rotor turbo would be wise at about 1000 HP for 400
MPH. It would need an intercooler
and perhaps water injection for take off. Running on gasoline. The
turbo compound part would take a lot
of R&D. It took us a year to get the TTC working well. We learned a
lot so another
identical craft would take 1/4 of the time. With a cowling my guess
is we could
go well over 300 MPH with the TTC and with a different prop..
So far nobody has built a small turbo compound aircraft engine let
alone a Wankel
version.
The CW radial turbo compound was 3350 cubic inches.
Paul Lamar
A while ago, Paul was talking about attaching a small drive shaft
to the turbo compressor end and driving a gear reduction box. The output
of that could drive another pulley on a serpentine belt.
The Glassair fuselage is reinforced with carbon fiber matting
behind the cabin for additional strength.
Rotary displacement calculation formula: 3square root x 3 x e x R x
width/1000. This gives displacement in cc per rotor face. Mazda uses one
face per rotor to get lower road tax. A larger engine gets taxed more.
So Mazda is calculating on one eshaft rotation. The engines are 4 stroke
cycle so most race sanctioning bodies double the Mazda displacement
claim. So for example of a 13B:
3 x squre root of 3 x (e) 15mm x (R) 105mm x width 80mm/1000 =
654.7 cc.
Mazda produced a JDM rotary for front wheel drive noted as 13A. The
internal dimensions were e 17.5, R 120mm, width 60mm. Plug the numbers
in and you get 654.7cc. Now if you used the same eshaft, gears and
radius dimensions but widen the rotors to 70mm you get 763.8cc.
105mm/15mm is a 7:1 ratio used in all Mazda production engines
other than the 13A. It had a ratio of 120/17.5 = 6.857:1. If you syrtch
the radius a bit to 125mm you would get 7.1429:1. Both are very close to
the 7:1 used in most Mazda production engines. If you used the eshaft
and gears from a 13A with rotors with a radius of 125mm and 70mm width
the displacement becomes 795.66cc. Very close to what Mazda would call a
16X. The rest of the world would call it a 3.2L engine.
Turbo RX8 are about 450HP unless you push the boost and tune. The
displacement increase from 2.616L to 3.183L should eqate to about 547HP.
If the power recovery gives 25% power increase because no valves the
power should be close to 685 HP. This is fairly mild. With higher boost,
1000HP should be easy. The Sport Class Glassair 3's are over 400MPH with
less power and I doubt you would blow an engine.
The TTC engine based on the larger displacement could be 650 HP x
1.217 for the displacement increase = 790HP. With power recovery; x 1.25
= 990HP.
Dale Davies
Paul and Dale,
I know this has been a source of disagreement in the pass but I feel
compelled to respond to the displacement narrative.
Displacement is defined as "c: the volume displaced by a piston (as in a
pump or engine) in a single stroke.
All manufactures of rotary engines use the same method as Mazda in
determining displacement.
The only people that define the rotary displacement differently are
sanctioning bodies to help competitors that must compete against it!
This is also done to handicap the two stroke engine.
A second idea for consideration. If we physically take the 3.15" wide X
7.5" long rotor (23.625 sq in) working against a very short 5/8" stroke
we get our 653 cc. When we add the 1500 psi to the above volume we get
torque.
If we could some how magically double this displacement we would double
torque and HP.
Let me concede that there is a clue that might indicate that it's
displacement is larger... and that is the way it drives a turbine wheel
causing turbo selection to be skewed larger than 4 strokes.
But in the end it is a very small and intriguing simple engine with a
very high heat load unencumbered by parasitic valve mechanisms.
My Take,
Barry Bordes
The rotary is not a two stroke. It is a four stroke.
Lets turn it around. How much air would a 2.6 liter two cylinder
TWO STROKE engine pump in one revolution?
As far as HP is concerned the ONLY thing that matters is how much
air a four stroke engine pumps in ONE REVOLUTION at 100% VE.
Not the physical displacement of x number of chambers.
The definition of displacement, as far as engines are concerned,
is only valid in context with the type of stroke.
Here is what Ansdale has to say about that.
13B rotaries are raced in the 2.6 liter class world wide
for a good reason. The only reason they generate more power
than a 2.6 liter four cylinder engine is they turn faster
and breath better. Lately that is less true as the piston
engine RPM has been raised by detail development and the
use of high strength to weight ratio materials like titanium.
Also four valves per cylinder has improved the breathing.
It is very rare for any 2 valve cylinder to have a VE over one.
The RX8 engine is just over one and P-ports are typically
1.2.
Formula One (2.5 liter as I recall) V8 engines were
turning 19,000 RPM. At least four valves per cylinder with
a very short stroke so larger valves can be used for a given
physical cylinder displacement. You will not find the details
of a competitive Formula One engine anywhere. Its a well
kept secret. However I would not be surprised if the VE's were
well over one. Applying the RPM difference to a 2.6L p-port rotary
making 340 HP at 10,000 RPM would make the Formula One engine
about 19,000/10,000 times 300 HP or 655 HP which is about
right for a Formula One engine in that period.
Paul Lamar
Paul,
It probably would be more correct to call a rotary a two sweep engine with 4 phases: intake, compression, power, and exhaust.
As you know there is no reciprocating type stroke involved.
The only comparison to the 2 stroke that I used was that it is also handicapped by sanctioning bodies because of its performance over a 4 stroke.
Did outlawing the peripheral port change its displacement?... no only its competitiveness. That after the rotary was penalized by giving the 4 strokes a double displacement advantage.
This does make sense to keep other manufactures competitive, profitable and happy. But it doesn't change the definition of displacement.
The cutaway picture of the rotary that you showed in Blue is exactly the depiction of its displacement. Displacement is not denoted by Ansdale's opinion... it is a dimensionally exact measurement.
Our little engines are indeed more powerful than most can envision.
Barry Bordes
The Ansdale definition of Wankel displacement is accepted by all the
world's engine engineers..
It is not an opinion. It is based on facts.
That's it period :-) You need to get his book and read it.
Paul Lamar
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