How is your set up different than the one Ed
A. had that didn't work too well? It was
also
one throttle split into two
runners.
I can't
really answer that question as I don't know the details of Ed's
design, and there may be differences that neither of us understands.
My
induction system is shown in the attached photo. A ram scoop feeds
(through a screen filter) an air box that I made from
fiberglass. It provides smooth transition (in lieu of air horns) to
the TB which has 44 mm barrels. Then divides through a custom short
manifold to the rotors. On set of injectors in the TB, the other
stock injectors in the side housings. I run the injectors in the TB
as 'primary' because they give me smoother low end
operation.
George –
I don't recall don't any detailed analysis in choosing the TB
diameter. I did look at the air velocity, and discussed with
Paul
Yaw and
David Akins; and made a 'best guess' for good breathing, and good
throttle response coming off low end.
A lot of
discussion is made of tuned induction and exhaust, however; my
primary consideration was simplicity and compact installation for
both. The system gives me easy start both hot and cold; and dyno
tests show very flat torque response from about 2500 rpm all the way
to 7000, with the corresponding nearly linear rise in HP to 300 hp
at 7000 rpm. Just started to see signs of a break in the power curve
at 7000 – which is as far up as we tested. This engine has the 9.0 :
1 compression turbo rotors.
It is
likely that longer runners, higher compression rotors, tuned exhaust
could get some more horses, but I have all I need for the
application. If you look at reinforcement
of intakes pulses on a 3-rotor, it turns out that the 12-13" that I
have from port to air box is a good distance at 5500 to 6000 rpm. I
made no effort to design the air box to direct these pulses, so
whether I get any help from that is open to debate.
So that's
about all I know. I'm happy it worked well on the first
try. Good luck on your Renesis.
BTW; the
intake manifold is 6061-T6 aluminum, weighs only about 2 lbs. It was
a serious challenge to fabricate. Fortunately, on the third
try, I found a very skilled machinist/welder who got it port-matched
at both flanges, and got the thing welded up. I then took it
to a heat treatment shop, and had it heat-treated back to T-6
condition.
Al G
--- On Sat, 2/7/09, Al Gietzen <ALVentures@cox.net>
wrote:
From: Al Gietzen <ALVentures@cox.net>
Subject: [FlyRotary]
Re: renesis intake possibility
To: "Rotary motors in aircraft"
<flyrotary@lancaironline.net>
Date:
Saturday, February 7, 2009, 3:04 PM
I use a
3-barrel TWM TB on my 20B with 44mm barrels. One barrel
(which divides into the 2 runners) for each rotor. It seem to work
quite well. As Ed mentioned, and supported by Paul
Yawʼs work,
high velocity in the barrel is a good thing. Maybe you could cut
the thing in half and use 2 barrels? I use the injector port in
the TB for MSD (Rochester)
injectors, and use the stock primary in the
housings.
Al
-----Original
Message-----
From:
Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bryan
Winberry
Sent:
Saturday, February 07,
2009 5:57
AM
To: Rotary motors in
aircraft
Subject:
[FlyRotary] renesis intake possibility
I have a chance to purchase a TWM
throttle body(see attch pic) at a very low
price. I have a couple questions for the
group.
The inlets are 42mm (appx 1.65
in.). Is this too big to the point that they would
be incompatible with the injectors? I plan on using
1-1/8 and1-1/4 in runners.
Also, the bosses are sized for
Bosch, Rochestor, or Lucas injectors. Does this
necessarily eliminate my using the stock Renesis
injectors?
This setup also would allow the use of
a lightweight airbox thus simplifying the intake
system from a manufacturing
standpoint.
RV7, Renesis,RD-1C,EC3,EM3 (in
the pipeline I hear)
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