X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qmta15.westchester.pa.mail.comcast.net ([76.96.59.228] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5567786 for flyrotary@lancaironline.net; Wed, 30 May 2012 09:20:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.59.228; envelope-from=wschertz@comcast.net Received: from omta16.westchester.pa.mail.comcast.net ([76.96.62.88]) by qmta15.westchester.pa.mail.comcast.net with comcast id GB8Z1j0041uE5Es5FDKkg6; Wed, 30 May 2012 13:19:44 +0000 Received: from WschertzPC ([71.57.77.95]) by omta16.westchester.pa.mail.comcast.net with comcast id GDKj1j01f23NHuF3cDKk3K; Wed, 30 May 2012 13:19:44 +0000 Message-ID: From: "Bill Schertz" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Injector balancing Date: Wed, 30 May 2012 08:19:42 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0024_01CD3E3C.F7025EE0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 15.4.3555.308 X-MimeOLE: Produced By Microsoft MimeOLE V15.4.3555.308 This is a multi-part message in MIME format. ------=_NextPart_000_0024_01CD3E3C.F7025EE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable How does it idle on secondaries? Bill Schertz KIS Cruiser #4045 N343BS Phase one testing Completed From: Mark Steitle=20 Sent: Tuesday, May 29, 2012 5:54 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Injector balancing Ernest, =20 With my current setup, this p-port engine idles better than my side-port = motor ever did. It will idle down to 750-800 rpm if asked, although I = normally idle at 1500-1600. Still, it might be an interesting = experiment to add temporary dividers in the airbox to see what effect it = would have on tuning. =20 If you take a close look at the picture I posted you can see the blue = fuel rail. This is the primary fuel rail feeding the primary injectors. = They're located downstream of the butterflies, very close to the intake = ports and pointed directly at the rotor faces. I can't imagine how the = fuel could find its way 18" back down the runner and back into the other = runners. I've never found any residual fuel in the airbox either. I = don't see how the fuel could be pooling so close to the ports, = especially at 4500 rpm. But then I'm not an expert in fuel injection = design either.=20 Alleviating fuel pooling in the runners was one of the design goals with = this latest intake. My previous slide throttle had both the primary and = secondary injectors located upstream of the slide. This caused fuel = pooling, especially at very low throttle settings. Needless to say, = this made low throttle tuning almost impossible. So, the new intake has = the primary injectors downstream of the butterflies, and it idles great. = =20 Mark On Tue, May 29, 2012 at 4:32 PM, Ernest Christley = wrote: Mark Steitle wrote: > Ernest, > > I don't understand how that could happen if my injectors are after = the > airbox (see attached pic). > > Mark At idle, the intakes coming off the airbox can set up some serious = standing waves that will suspend fuel droplets and let it stick to the walls. You're set-up is very similar to mine, in = that the fuel can run downhill and air has to pass in front of one runner before reaching the others. Some of that = suspended fuel will coalesce on the wall and drivel down the runner, and any coming out of the middle will get pushed back = to the rear (which will then be running over rich). It would also be interesting to watch individual MAPs across the = runners. Dollars to donuts that the first runner's inlet is at a partial vacuum compared to the rear one. I may be wrong about the mechanism, but I know my fix fixed whatever = was wrong. I inserted a plate so that the runners could not "see" the air intake. The air hits the plate and spreads = out before heading to the runners directly, instead of flying past the first on the way to the second. Going off of what I think I know, I would use a handsaw to cut a slot = halfway through the plenum between the runners. Then I would slide a partition between them. It would essentially = create three stalls that the runners originate from. The point being that air would not be able to go past one runner on = the way to the second. -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0024_01CD3E3C.F7025EE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
How does it idle on secondaries?
 
Bill=20 Schertz
KIS Cruiser #4045
N343BS
Phase one testing = Completed
 
Sent: Tuesday, May 29, 2012 5:54 PM
Subject: [FlyRotary] Re: Injector = balancing
 
Ernest, =20
 
With my current setup, this p-port engine idles better than my = side-port=20 motor ever did.  It will idle down to 750-800 rpm if asked, = although I=20 normally idle at 1500-1600.  Still, it might be an interesting = experiment=20 to add temporary dividers in the airbox to see what effect it would have = on=20 tuning. 
 
If you take a close look at the picture I posted you can see the = blue fuel=20 rail.  This is the primary fuel rail feeding the primary = injectors. =20 They're located downstream of the butterflies, very close to the intake = ports=20 and pointed directly at the rotor faces.  I can't imagine how the = fuel=20 could find its way 18" back down the runner and back into the other=20 runners.  I've never found any residual fuel in the airbox = either.  I=20 don't see how the fuel could be pooling so close to the ports, = especially at=20 4500 rpm.  But then I'm not an expert in fuel injection design = either.=20
 
Alleviating fuel pooling in the runners was one of the design goals = with=20 this latest intake.  My previous slide throttle had both the = primary and=20 secondary injectors located upstream of the slide.  This caused = fuel=20 pooling, especially at very low throttle settings.  Needless to = say, this=20 made low throttle tuning almost impossible.  So, the new intake has = the=20 primary injectors downstream of the butterflies, and it idles = great.  =20
 
Mark
 


On Tue, May 29, 2012 at 4:32 PM, Ernest = Christley <echristley@att.net> wrote:
Mark Steitle wrote:
> Ernest,
>
> I = don't=20 understand how that could happen if my injectors are after the
> = airbox=20 (see attached pic).
>
> Mark

At idle, the = intakes=20 coming off the airbox can set up some serious standing waves that will = suspend=20 fuel droplets and
let it stick to the walls.  You're set-up is = very=20 similar to mine, in that the fuel can run downhill and air has to = pass
in=20 front of one runner before reaching the others.  Some of that = suspended=20 fuel will coalesce on the wall and drivel
down the runner, and any = coming=20 out of the middle will get pushed back to the rear (which will then be = running=20 over rich).

It would also be interesting to watch individual = MAPs=20 across the runners.  Dollars to donuts that the first = runner's
inlet=20 is at a partial vacuum compared to the rear one.

I may be wrong = about=20 the mechanism, but I know my fix fixed whatever was wrong.  I = inserted a=20 plate so that the runners
could not "see" the air intake.  The = air=20 hits the plate and spreads out before heading to the runners directly, = instead
of flying past the first on the way to the = second.

Going off=20 of what I think I know, I would use a handsaw to cut a slot halfway = through=20 the plenum between the runners.
Then I would slide a partition = between=20 them.  It would essentially create three stalls that the runners=20 originate from.
The point being that air would not be able to go = past one=20 runner on the way to the second.

--
Homepage:  http://www.flyrotary.com/
Archive and = UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.htm= l
 
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