X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [137.118.16.51] (HELO smtp1.av-mx.com) by logan.com (CommuniGate Pro SMTP 5.4.6) with ESMTP id 5644115 for flyrotary@lancaironline.net; Mon, 09 Jul 2012 12:41:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=137.118.16.51; envelope-from=res12@fairpoint.net Received: from MAIN (unknown [66.243.228.156]) (Authenticated sender: res12@fairpoint.net) by smtp1.av-mx.com (Postfix) with ESMTP id 53BE02920D6 for ; Mon, 9 Jul 2012 12:41:07 -0400 (EDT) Message-ID: From: "Richard Sohn" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: First lift off with single rotor Date: Mon, 9 Jul 2012 11:40:57 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0058_01CD5DC7.B4E5DA50" 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_0058_01CD5DC7.B4E5DA50 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Brian, I have no engine controller. Fixed timing electronic ignition and a = ROTEC TB injector.=20 My problem starts at about 40MPH.=20 Richard Sohn N2071U http://www.fairpoint.net/~res12/home.html From: bktrub@aol.com=20 Sent: Monday, July 09, 2012 11:24 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: First lift off with single rotor What type of engine controller do you have? And what RPM is the engine = at when it starts to sputter. I had the same sort of issue- the engine = ran fine on the ground, but after liftoff, at about 50 feet, the engine = would start to backfire and sputter. The issue was the polarity of the = CAS was reversed. I am using the RWS EC2. Maybe the same issue with you, = maybe not. It was a real buzzkill, let me tell you. I wouldn't say it = scared me, but I would say that I was doing a lot of soul searching = about that time.=20 Brian Trubee -----Original Message----- From: Ernest Christley To: Rotary motors in aircraft Sent: Mon, Jul 9, 2012 9:13 am Subject: [FlyRotary] Re: First lift off with single rotor Richard Sohn wrote: > Cleared the ground for a brief period today. As far as the airplane is > concerned, everything is good. CG seems to be right on the spot. Much > better as it was 12 years ago at the first flight with the SOOB. > Here is the reason why it was not a flight. A few days ago when I > started high speed taxi, as soon as it picked up air speed, the engine > started to sputter and almost cut out totally. This was at the same = RPM > as at a run up, where it does not do that. With a wiggly tail dragger = as > the Avid is, there was no way reading enough instrument for making a > preliminary analysis. I recorded the instrument panel with a GoPro at > 2sec intervals. > Looking at the first pictures, the answer came up right away, = increasing > pressure under the cowl where the intake for the engine is located. = Like > the EGT shot up over 1600 just before the sputtering started. Since my > radiator air is going to the outside of the cowling, there was no = impact > on cooling. Btw cooling is really good. At an OAT of 95F, oil and = water > stayed at around 170F no matter what I did. > =20 > For todays runs, I taped the inlet around the prop hub shut. Sure > enough, the sputtering occurred at higher airspeed, and was not as > total, however, EGT was still going to around 1600. > =20 > The conclusion is, I have to open the cowling exits a lot. I don't get it. The pressure under the cowl sounds like it would be a = good=20 thing, because it sounds like it is enough to cause the engine to lean out. If the cooling isn't a problem, why = wouldn't=20 you just enrichen the mixture to accommodate the extra air and accept the increase in power? -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0058_01CD5DC7.B4E5DA50 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Brian,
 
I have no engine controller. Fixed timing electronic ignition and a = ROTEC=20 TB injector.
My problem starts at about 40MPH.
 
Richard=20 Sohn
N2071U

http://www.fairpoint.net/~res12/home.html
 
Sent: Monday, July 09, 2012 11:24 AM
Subject: [FlyRotary] Re: First lift off with single=20 rotor
 
What type of engine controller do you have? And what RPM is the = engine at=20 when it starts to sputter. I had the same sort of issue-  the = engine ran=20 fine on the ground, but after liftoff, at about 50 feet, the engine = would start=20 to backfire and sputter. The issue was the polarity of the CAS was = reversed. I=20 am using the RWS EC2. Maybe the same issue with you, maybe not. It was a = real=20 buzzkill, let me tell you. I wouldn't say it scared me, but I would say = that I=20 was doing a lot of soul searching about that time.
 
Brian Trubee


-----Original=20 Message-----
From: Ernest Christley <echristley@att.net>
To: = Rotary=20 motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, Jul = 9, 2012=20 9:13 am
Subject: [FlyRotary] Re: First lift off with single = rotor

Richard Sohn wrote:
> Cleared the ground for a brief period today. As far as the airplane =
is
> concerned, everything is good. CG seems to be right on the spot. =
Much
> better as it was 12 years ago at the first flight with the SOOB.
> Here is the reason why it was not a flight. A few days ago when I
> started high speed taxi, as soon as it picked up air speed, the =
engine
> started to sputter and almost cut out totally. This was at the same =
RPM
> as at a run up, where it does not do that. With a wiggly tail =
dragger as
> the Avid is, there was no way reading enough instrument for making =
a
> preliminary analysis. I recorded the instrument panel with a GoPro =
at
> 2sec intervals.
> Looking at the first pictures, the answer came up right away, =
increasing
> pressure under the cowl where the intake for the engine is located. =
Like
> the EGT shot up over 1600 just before the sputtering started. Since =
my
> radiator air is going to the outside of the cowling, there was no =
impact
> on cooling. Btw cooling is really good. At an OAT of 95F, oil and =
water
> stayed at around 170F no matter what I did.
> =20
> For todays runs, I taped the inlet around the prop hub shut. Sure
> enough, the sputtering occurred at higher airspeed, and was not as
> total, however, EGT was still going to around 1600.
> =20
> The conclusion is, I have to open the cowling exits a lot.

I don't get it.  The pressure under the cowl sounds like it would be a =
good=20
thing, because it sounds like it is enough
to cause the engine to lean out.  If the cooling isn't a problem, why =
wouldn't=20
you just enrichen the mixture to
accommodate the extra air and accept the increase in power?

--
Homepage:  http://www.flyrotary.com/
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