Yeah, about the bitmaps, sorry. Must have been a 1a.m. oversight. Rhino is
really an amazing software. I was astonished how 'pick-up and play' the
controls are. So far I have about 5 hour of play time with it.
I now the grey tubes are a bit short for best performance but hopefully an
arrangement like that will allow people with very tight cowls to actually
use the Holley. I attached a few more designs that have longer runner but
the placement makes carb heat plumbing a pain. I can't image running a heat
duct over the engine so perhaps electric heating is the only option with
having the carburetor on the 'other' side of the engine. what are your
thoughts on the 2-1-2 vs 1 all the way arrangement?
As a side note, Cummings uses an electric 'grid' heater on their diesel
engines. Maybe something like that could be adapted for aviation.
Vlad
On Wed, May 20, 2009 at 1:55 AM, Rotary Engine <
rotaryeng@earthlink.netwrote:
So I finally stopped being lazy and quickly put together a Rhino rendering
of my idea about the Holley set-up. The grey is obviously a intake
manifold
for a PP rotary, the red is a crudely drafted Holley 2300 2bbl carburetor
and the blue is the rest of the intake system. The manifold and carb are
self explanatory but I figured I'd explain the blue system. Right above
the
carb is a circular plenum with 1 outlet for carb heat and the other for
regular operations. On the carburetor heat side is a butterfly valve and a
dump tube like on other carb heat boxes. The other regular operations tube
leads over the engine and down the side before ending in a cone filter. My
idea is that by locating the carb in this manner, you lessen the chances
of
any clearance problems with the cowl and have an easy route for carb heat
while still having a long intake to locate the torque curve in more
appropriate rpm range. I now that the dimensions are way off and that the
rendering is not very detailed but at least this could help better present
my idea.
Vlad
Good work Vlad. Glad to see you up to speed on Rhino.
How long have you been using Rhino. If just a short time you
are a fast learner. Please save and send them as jpg's as bmp's are too
large.
I converted them this time but I had to go on the server and delete them.
The engine will run fine but the gray tubes are too short for optimum
power
and lowest BSFC. The blue tube does not see the necessary pulsations
from the p-ports to trigger resonating. It might work if it were half
as long as it may see pulses from both rotors 180 degrees out of phase.
The last three 3D's are some ideas on carb heat and alternate air
valves we did quite some time ago.
-------------------------------------------------
Here is a better Holley 2 barrel Vlad.
Still not perfect. The flange is not to scale.
Here is a dwg.jpg I found.
If you fix the flange please send me the 3DM.
--------------------------------------------------
I took a closer look at the Holley recommendations and extrapolated their chart
to 200 cubic inches and 7500 RPM max. The 350 CFM 2 barrel might give
smoother running at 5000 to 6500 cruise RPM's with a slight sacrifice
in take off power. The p-port rotary is 120% VE and 160 cubic inches so
that makes it about equivalent to a 200 cubic inch piston engine.
So that puts the requirements right around 400 CFM. Looks like right
in the middle between the 350 and the 500. I would go for the 350 for
lower fuel burn and the 500 for max power.
Paul Lamar
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