X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from securemail.ever-tek.com ([64.129.170.194] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3882187 for flyrotary@lancaironline.net; Sun, 11 Oct 2009 01:47:48 -0400 Received-SPF: none receiver=logan.com; client-ip=64.129.170.194; envelope-from=cbarber1@texasattorney.net Received: from fcd-mail05.FCDATA.PRIVATE ([172.16.5.24]) by FCD-MAIL03.FCDATA.PRIVATE with Microsoft SMTPSVC(6.0.3790.3959); Sun, 11 Oct 2009 00:47:24 -0500 Received: from fcd-mail05.FCDATA.PRIVATE ([4.4.5.9]) by fcd-mail05.FCDATA.PRIVATE ([4.4.5.9]) with mapi; Sun, 11 Oct 2009 00:47:10 -0500 From: Chris Barber To: Rotary motors in aircraft Date: Sun, 11 Oct 2009 00:44:10 -0500 Subject: RE: [FlyRotary] where's the missing power? Thread-Topic: [FlyRotary] where's the missing power? Thread-Index: AcpKIt+3dQpk8wMXR2mqB9xGSAX6EgAEvy74 Message-ID: <6A3D27B02C7348499A682286EDB23105020C37A865@fcd-mail05.FCDATA.PRIVATE> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_6A3D27B02C7348499A682286EDB23105020C37A865fcdmail05FCDA_" MIME-Version: 1.0 Return-Path: cbarber1@texasattorney.net X-OriginalArrivalTime: 11 Oct 2009 05:47:24.0900 (UTC) FILETIME=[4F15D240:01CA4A36] --_000_6A3D27B02C7348499A682286EDB23105020C37A865fcdmail05FCDA_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Mike, For what its worth I get full power before the throttle is full open too an= d my intake is the professionally designed and manufactured Mistral intake.= I have not been too distracted by it yet and I am not flying and it is gi= ving me about 6000 rpm static. Just another data point. All the best, Chris Barber Houston ________________________________ From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of = Mike Wills [rv-4mike@cox.net] Sent: Saturday, October 10, 2009 10:27 PM To: Rotary motors in aircraft Subject: [FlyRotary] where's the missing power? I noticed quite a while ago and have mentioned several times here that my e= ngine does not have a linear response to throttle. It reaches its max power= before it reaches fully open throttle. I havent worried too much about thi= s up until now because the airplane has sufficient power as is, has slightl= y better performance than my previous 160HP Lyc powered -6A, and my wood pr= op is actually a pretty good match for the current power level. But I would like to understand what's going on here and eventually address = it. I was flying yesterday, my usual boring holes in the sky directly over = the airport. Decided to investigate just a little so leveled at 5,000 feet = at full throttle. Started reducing throttle until I noticed a slight reduct= ion in RPM and fuel flow. Then looked down at where the throttle was actual= ly set and was shocked to see it slightly below half open. I dont have a re= gular manifold pressure gauge, just an industrial type vacuum gauge ( I rea= lly gotta get an MP gauge). Anyway, the vacuum gauge was indicating 4" of v= acuum. So I suspect I am giving up a substantial amount of HP. I think the most li= kely suspect is my throttle body. For a throttle body I copied Tracy's orig= inal design. Started with a stock late 80s Mazda TB and hacked off the thir= d port and all of the extra stuff. The cowl in this area is very tight and = I am unable to install any sort of air filter or any sort of bell mouth on = the TB. And I'm sure the cowl's close proximity to the TB influences airflo= w into it as well. Any comments on this or ways to test it are welcome. Mike Wills RV-4 N144MW --_000_6A3D27B02C7348499A682286EDB23105020C37A865fcdmail05FCDA_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Mike,
 
For what its worth I get = full power before the throttle is full open too and my intake is the profes= sionally designed and manufactured Mistral intake.  I have not be= en too distracted by it yet and I am not flying and it is giving me about 6000 rpm static.  Just another data point.<= /font>
 
All the best,
 
Chris Barber
Houston
From: Rotary motors in aircraft [fl= yrotary@lancaironline.net] On Behalf Of Mike Wills [rv-4mike@cox.net]
Sent: Saturday, October 10, 2009 10:27 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] where's the missing power?

I noticed quite a while ago and have m= entioned several times here that my engine does not have a linear response = to throttle. It reaches its max power before it reaches fully open throttle= . I havent worried too much about this up until now because the airplane has sufficient power as is, has slightly= better performance than my previous 160HP Lyc powered -6A, and my wood pro= p is actually a pretty good match for the current power level.
 
But I would like to understand what's = going on here and eventually address it. I was flying yesterday, my usual b= oring holes in the sky directly over the airport. Decided to investigate ju= st a little so leveled at 5,000 feet at full throttle. Started reducing throttle until I noticed a slight reduc= tion in RPM and fuel flow. Then looked down at where the throttle was actua= lly set and was shocked to see it slightly below half open. I dont have a r= egular manifold pressure gauge, just an industrial type vacuum gauge ( I really gotta get an MP gauge). An= yway, the vacuum gauge was indicating 4" of vacuum.
 
So I suspect I am giving up a substant= ial amount of HP. I think the most likely suspect is my throttle body. For = a throttle body I copied Tracy's original design. Started with a stock= late 80s Mazda TB and hacked off the third port and all of the extra stuff. The cowl in this area is very tight and I= am unable to install any sort of air filter or any sort of bell mouth on t= he TB. And I'm sure the cowl's close proximity to the TB influences airflow= into it as well.
 
Any comments on this or ways to test i= t are welcome.
 
Mike Wills
RV-4 N144MW
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