Alex Madsen wrote:
Last week I finished my concept drawing for a tuned carbon fiber
intake manifold which I may eventual start producing. After three
designs I finally got
something I liked. There are several things I sill need to change
(clearances, remove flat surfaces, move plenum entrance to side, and
further reduce height
above engine ect). The engine block is a sketch I roughly scaled
from a drawing with calipers. If anyone has a solid model of the 13B
they could send to me
it would appreciate it. The runners are flattened 2 in. tube with a
hydraulic diameter of 1.8 in and a length of 30 in. . I think the 30 in.
is a bit long but
I need to start somewhere. The height of the manifold above the top
of the engine is about 3.5 in. The plenum has a volume of 1.12 L.
I am in the middle of finals at the moment so I have not had time to
refine the drawing.
Comment Questions
Alex Madsen
Jr. Mechanical Engineer
Rose-Hulman
Nice 3D work Alex. I did something similar awhile back. Kind of tough
to get the primary tuned length short enough to use the dynamic
chamber principle at 7500 RPM. Never know for sure unless we tried
one on a dyno. The last 3D is one I did.
The stock Mazda dynamic chamber is tuned for 6000 RPM for the long
legs
and 3000 RPM in the dynamic chamber mode. You can see the torque hump
at 3000 RPM in the NA HP charts. Something we really don't need in
an aircraft engine.
Ed Anderson and I went around and around on this. He is currently
flying a version that is cockpit adjustable. However without a dyno
it is hard to prove it is working or not working.
A lot of systems also add a tuned length pipe from the dynamic chamber
to the air cleaner. The RX8 uses this principle with multiple dynamic
chambers to fatten the torque curve throughout the RPM range.
BTW IMHO there is no replacement for displacement when it comes to low
RPM
torque. That is why I am pushing Mazda management for a 3 rotor in the
RX8 :)
Paul Lamar
Alex, IMHO here is what it is going to take to get the dynamic chamber
working
in our RPM ranges. Namely 6000 to 7500. Lots of R&D work for very little
potential
gain.
IMHO we are much better off going with the Leman P-port configuration.
120 HP per rotor is guaranteed at 6000 RPM and 155 HP per rotor at 7500
RPM with a 2.85:1 gear box. That is 240 HP at 6000 RPM and 310 HP at
7500 RPM.
You won't come close to those numbers with side intake ports and dynamic
chambers. As I said before the hot tip ultimately will be P-port intakes
with side exhaust ports.
Paul Lamar
-Alex Madsen wrote:
Where can I get detailed information on Leman P-port configuration
design? Any information people could send me on intake manifolds for
rotary engines would be very helpful. I am also looking for 2D or 3D
drawings (solid works preferred) of the 13B housing. Don't worry about
clogging my e-mail I have 100mb.
Alex Madsen
madsen@rose-hulman.edu
Alex check the web site below for a list of SAE papers. The one you want
is SAE 920309 on the Leman engine. I assume your school library has SAE papers.
If you can't find a copy let me know.
BTW Don't get too focused on this Alex. Your highest priority should be grades :)
That is a mistake I made when I was in college. Spent too much time at the
Library of Congress researching vehicle dynamics culminating in a paper I wrote for
the AIAA called Aerodynamics & The Group Seven Racing Car.
Presented at the AIAA Symposium on The Aerodynamics
of Sports & Competition Automobiles. April 20 1968
Paul Lamar
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