I
usually keep my mouth shut when it comes to
P port
discussions. I agree with everything Bill has written with one exception. I
doubt the big
p ports are advantageous at our RPM. A 1.5"
i.d. port will flow 7500 rpm, no problem. The smaller ports
are easier to time (less overlap) and the smaller
dia.
intake tubes are much easier to fit.
jerry On Jun 18, 2007, at
1:01 PM, Richard
Sohn wrote:
>
Bill,
>
> AMEN to all.
>
>
Richard
Sohn >
N2071U > ----- Original Message ----- From: <
wrjjrs@aol.com>
> To: "Rotary
motors in aircraft" <
flyrotary@lancaironline.net>
>
Sent: Monday, June 18, 2007 11:12 AM
> Subject: [FlyRotary] Re:
Fw: Different Rotary Port
configurations
>
>
>
>
>
Guys,
> Lets cut to the chase. The
P-port
rotary will idle fine. The original
>
12As were
p-port. Lots of the
NSU wankels were
p-port. John Deere
and
> MB
C111 engines were
p-port. There was no comment that these engines
>
didn't idle. Perhaps not as smoothly as the side port engines, but >
idle
> none the less. The
P-port makes the most
power, period. Mazda wouldn't
> have used the
P-port only on their
LeMans engine if
combination ports
> would have worked better. Don't think for a
second they didn't try
> other configurations either. They used
the far trailing plug to > improve
> efficiency less than 2%.
Richard's work showed no improvement to power
> with the side
port/
p-port combo. Anywhere but idle my guess would
be
> that the inrush from the
p-port probably
causes minimal flow in the
> side ports. The
p-port is open much sooner and flow is underway by
the
> time the side port opens. If we had a source for finished
p-port
> housings that cost the same as the
standard housings we would all be
> using them and the discussion
would cease and we would move on to > other
> subjects. For
aircraft use the big
p-port is for most cases the
best
> possible solution. We can improve on minor details, but not
much. The
> simpler
manifolding and more
compact package when using fewer tubes > for
> the intake are
all pluses for the
p-port. We don't have car low
RPM
> issues to worry about. If a good source of the Mazda racing
p-port
> housings was available for the same
price as standard housings I'd > have
> 3 on order right now.
(
20B remember)
> Bill
Jepson
>
>
>
>
>
Well, Mark - perhaps in the
future
>
>
>
> Only so much
time and so many things that would be fun to try. IF I
> interpret
the charts correctly the
P + S type intake
configuration
> appears to provide much more intake port area than
either the
P or S
> type along. Makes sense -
if you have twice as many intakes it has
> more area. Supposedly
the
P+S overcomes the low rpm idle problem of
>
the
PP
alone.
>
>
>
> But, for
aircraft usage, I think Richard is on the money, you don't
>
really spend much time at idle in aircraft usage and I idle above
1600
> rpm in any case, so who cares {:>) - just go with the
P
port.
>
>
>
> However, I am
intrigued by the large intake area that the
P +
S
> configuration has over even the
PP alone and what that might potent
> for POWER! More
Power, Scotty!!!!!
>
>
>
> Saw
some information on the
Renesis in an
SAE paper that indicates the
> six port (They call it
the HIGH POWER
Renesis) produces 40% more
power
> than the standard
13B. They did not
make a comparison to the 4 port
>
Renesis but
presumably it produces less than the six port
Renesis
but
> more than the older
13B. They also didn't
specify the rpm point that
> occurred, but I assume it must be
near its maximum. Also, its not
> clear if this figure was based
on the earlier 250 HP claim for the
>
Renesis
by Mazda or the later adjusted 237 HP claim (actually I'd take
>
either one) .
>
>
>
> The
intake configuration and operation on the six port is quite
>
involved, but they do make use of the Dynamic Effect. They call it
the
> Sequential Dynamic Air Intake System (S-DAIS). Since there
is no
> intake/exhaust port overlap in the
Renesis, they appear to make use of
> the "A" pulse
which is the pressure wave created when the high > velocity
>
air in the intake slams into the closing port and bounced back down >
the
> manifold. They then have several valves that activate at
different
> rpm/air flow situations that control the sequential
activation of
> elements of the
S-DAIS.
>
>
>
> As well as the
"A" pulse, the older
NA 13B DEI also used the stronger
> "B" pulse created when
the intake opened releasing a burst of the
> trapped exhaust gas
residue to create a power shock wave which raised
> the manifold
pressure at the second rotor's intake. But, since there
> is no
intake/exhaust overlap with the
Renesis side ports, it
would
> appear that only the "A" pulse is used to enhance
power.
>
>
>
>
Ed
>
>
>
>
>
>
>
----- Original Message -----
>
> From: Mark
Steitle >
> To: Rotary motors in
aircraft
>
> Sent: Monday, June 18, 2007 9:12
AM
>
> Subject: [FlyRotary] Re:
Fw:
Different Rotary Port
configurations
>
>
>
>
>
Thanks Richard for the
clarification.
>
>
> Mark
S.
>
> (Looks like I should have typed a little
faster.)
>
>
> On 6/18/07, Mark
Steitle <
msteitle@gmail.com>
wrote:
>
> Well Ed,
>
> It
looks like you've got yourself a new intake project. Didn't
Richard
>
Sohn try running side and peripheral
intake porting on his one rotor?
> I vaguely remember him
mentioning it and that he abandoned the idea. I
> think it had
something to do with the complexity of the dual runners
> and that
he was satisfied with the idle characteristics of the
p-port?
> Maybe Richard can
comment?
>
>
>
> Mark
S.
>
>
>
> On 6/17/07, Ed
Anderson <
eanderson@carolina.rr.com >
wrote:
>
>
> Ok, here's the answer to my
question. The second image shows a three
> barrel
carb with the primary going to two side intake ports and
the
> secondary going to the Peripheral ports. Interesting
concept.
>
>
>
>
Ed
>
>
> ----- Original Message
-----
> From: Ed Anderson
>
> To: Rotary
motors in aircraft
>
> Sent: Sunday, June 17, 2007
10:15 PM
>
> Subject: Different Rotary Port
configurations
>
>
>
>
>
>
Ok, getting a bit quite again. Here is something that some of you
may
> find interesting. Its a graph comparing the possible
different port
> configurations for the Rotary
engine.
>
> The top graph shows the intake and exhaust
port opening for a engine
> with a peripheral intake and
peripheral exhaust - such as a
13B which
> has
been converted to a
PP
intake.
>
>
>
> The
trapezoidal shapes show the port area. For example on the first
>
graph the first rectangular area entitled PORT shows the
Peripheral
> exhaust port open at
63Deg ATDC. There are two trapezoid areas shown
> for the
Peripheral intake. A "
P" which I presume stands for
Primary
> and a much larger
P+S which I
presumes stands for a combined primary
> and Secondary port.
Although, I do not ever recall a
PP with
two tubes
> one for primary and one for secondary. So there may be
another
>
explanation.
>
>
>
> The
second graph is our traditional
13B with
sideport intake and
> peripheral port exhaust. Here
the intake timing for the intake is that
> of the
NA 13B although it shows the intake opening a
bit later than > the
> stock
13B but closing
at the stock 40 deg
ABDC.
>
>
>
> If
you look at the area under the first graphs "
P" trapezoid
it > appears
> to be open much longer than the
P for the side port intake (2nd > graph),
> but
the trapezoid is not as high. Wonder what that signifies? Open
>
longer but not as large a port
area?
>
>
>
> Anyhow, thought
some of you might find it
interesting.
>
>
>
>
>
>
Ed Anderson
>
Rv-
6A N494BW Rotary Powered
> Matthews, NC
>
eanderson@carolina.rr.com >
http://members.cox.net/rogersda/rotary/configs.htm#N494BW >
http://www.dmack.net/mazda/index.html >
>
>
>
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