X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-ma02.mx.aol.com ([64.12.206.40] verified) by logan.com (CommuniGate Pro SMTP 5.4.6) with ESMTP id 5644428 for flyrotary@lancaironline.net; Mon, 09 Jul 2012 15:35:53 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.206.40; envelope-from=bktrub@aol.com Received: from mtaomg-db01.r1000.mx.aol.com (mtaomg-db01.r1000.mx.aol.com [172.29.51.199]) by imr-ma02.mx.aol.com (8.14.1/8.14.1) with ESMTP id q69JZ6ll020422 for ; Mon, 9 Jul 2012 15:35:06 -0400 Received: from core-dub005c.r1000.mail.aol.com (core-dub005.r1000.mail.aol.com [172.29.164.82]) by mtaomg-db01.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 8F544E000089 for ; Mon, 9 Jul 2012 15:35:06 -0400 (EDT) References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: On the step In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: bktrub@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CF2C2113D92936_168C_173194_webmail-d041.sysops.aol.com" X-Mailer: AOL Webmail 36542-STANDARD Received: from 23.25.136.85 by webmail-d041.sysops.aol.com (205.188.181.84) with HTTP (WebMailUI); Mon, 09 Jul 2012 15:35:06 -0400 Message-Id: <8CF2C2113CFA3A6-168C-6CAE9@webmail-d041.sysops.aol.com> X-Originating-IP: [23.25.136.85] Date: Mon, 9 Jul 2012 15:35:06 -0400 (EDT) x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1341862506; bh=liWKS3jRqCJ+0SYY4PJDhTojrt/IH3IxBpg8EsXosdU=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=k/jnZcxLE99ISgfG4+32vnHjh2JUvjst+2nb5pvddsGqgTj+h3/mfe+ymHIAvYKn+ Ic1g5+EcxHVud1STPi2pBd90w1smKam9x/aaasUsBEzXGTrOwvZR/hnsqGzOSh3Z0w keQBQIb01JYVI/WW+ldbaq4X+qJXhQi4JYY83pmQ= X-AOL-SCOLL-SCORE: 0:2:380475424:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d33c74ffb326a3137 This is a multi-part message in MIME format. ----------MB_8CF2C2113D92936_168C_173194_webmail-d041.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" RV-4 with 13 BREW/NA, turbo rotors- 9.1/1, four port, running ~8 gph. Stat= ic timing is right where it should be, I don't recall the advance at the mo= ment. Slower than other RV-4s at this time, but not too worried about speed= at this juncture- just enjoying the trouble free flying after 15 years of = building. I'll worry about refinements during our long, grey, raining wint= er.=20 Brian Trubee -----Original Message----- From: Mark Steitle To: Rotary motors in aircraft Sent: Mon, Jul 9, 2012 11:12 am Subject: [FlyRotary] Re: On the step Brian, What's your fuel burn at 140-150 mph? How long are your intake unners? I assume you've checked and verified your static timing? hat airframe is this? How does your performance compare to other a/c f the same make/model, but running certified engines? As Lynn H. has tressed many times before... the devil's in the details. Mark S. n 7/9/12, bktrub@aol.com wrote: I commented on here recently about how I took a cross- country flight to Walla Walla from Everett, Wa recently and was only seeing 140-150 mph crui= se at 11,500 feet. It got me to thinking- I was getting about 6200 rpm on the engine which is 2175 at the prop. So, I'm a little overpropped/ underpowered. So, there's the old chestnut about how you can get a few more knots from a= n airplane in cruise if you go a little above your cruise altitude and then descend to your cruise altitude, thereby getting "on the step" . Some pilo= ts swear by this, others dismiss it. I have a theory- if I climb to a cruise altitude and stay at full throttle while doing so, I will only get the engine to run up to a certain RPM and therefore a certain hp will be achieved, and no more and so the airplane will settle into an equilibrium = at a certain speed- say at whatever hp/speed - 140 mph at 6200 rpm- lt's say = x hp. Now, If I were to descend to my cruise altitude in a shallow dive, I will = be acheiving a higher rpm and hence horsepower, say 6800 rpm and horsepower will be x + 9%x for a hp of 109% of the hp achieved at 6200 rpm, so I shou= ld be able to achieve and maintain a higher cruise speed if I descend to my cruising altitude. ( I picked 9% arbitrarily for the sake of argument) . Anyone want to shoot me down on this one? This is just an theory, If I want to go faster first I have to clean up my drag. My cooling scoop is effective, but obviously draggy. And It needs a flap on it. That's a project for this winter. Brian Trubee -- omepage: http://www.flyrotary.com/ rchive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.h= tml ----------MB_8CF2C2113D92936_168C_173194_webmail-d041.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii"
RV-4 with 13 BREW/NA, turbo rotors- 9.1/1, four  port, running ~8= gph. Static timing is right where it should be, I don't recall the advance= at the moment. Slower than other RV-4s at this time, but not too worried a= bout speed at this juncture- just enjoying the trouble free flying after 15= years of building. I'll worry about refinements during  our long, gre= y, raining winter.
Brian Trubee


= -----Original Message-----
From: Mark Steitle <msteitle@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, Jul 9, 2012 11:12 am
Subject: [FlyRotary] Re: On the step

Brian,

What's your fuel burn at 140-150 mph?  How long are your intake
runners?  I assume you've checked and verified your static timing?
What airframe is this?  How does your performance compare to other a/c
of the same make/model, but running certified engines?  As Lynn H. has
stressed many times before... the devil's in the details.

Mark S.


On 7/9/12, bktrub@aol.com <bktrub@aol.com> wrote:
>
> I commented on here recently about how I took a cross- country flight =
to
> Walla Walla from Everett, Wa recently and was only seeing 140-150 mph =
cruise
> at 11,500 feet. It got me to thinking- I was getting about 6200 rpm on=
 the
> engine which is 2175 at the prop. So, I'm a little overpropped/
> underpowered.
>
> So, there's the old chestnut about how you can get a few more knots fr=
om an
> airplane in cruise if you go a little above your cruise altitude and t=
hen
> descend to your cruise altitude, thereby getting "on the step" . Some =
pilots
> swear by this, others dismiss it. I have a theory- if I climb to a cru=
ise
> altitude and stay at full throttle while doing so, I will only get the
> engine to run up to a certain RPM and therefore a certain hp will be
> achieved, and no more and so the airplane will settle into an equilibr=
ium at
> a certain speed- say at whatever hp/speed - 140 mph at 6200 rpm- lt's =
say x
> hp.
>
> Now, If I were to descend to my cruise altitude in a shallow dive, I w=
ill be
> acheiving a higher rpm and hence horsepower, say 6800 rpm and horsepow=
er
> will be x + 9%x for a hp of 109% of the hp achieved at 6200 rpm, so I =
should
> be able to achieve and maintain a higher cruise  speed if I descend to=
 my
> cruising altitude. ( I picked 9% arbitrarily for the sake of argument)=
 .
>
> Anyone want to shoot me down on this one?
>
> This is just an theory, If I want to go faster first I have to clean u=
p my
> drag. My cooling scoop is effective, but obviously draggy. And It need=
s a
> flap on it. That's a project for this winter.
>
> Brian Trubee
>

--
Homepage:  http://www=
.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net:81/lists/fly=
rotary/List.html
----------MB_8CF2C2113D92936_168C_173194_webmail-d041.sysops.aol.com--