X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3882192 for flyrotary@lancaironline.net; Sun, 11 Oct 2009 01:55:17 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (sv1-1.per.aanet.com.au [203.24.100.68]) by poplet2.per.eftel.com (Postfix) with ESMTP id B2EF1173974 for ; Sun, 11 Oct 2009 13:54:40 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id BA6A0BEC004 for ; Sun, 11 Oct 2009 13:54:38 +0800 (WST) Message-ID: <2A0A5E12FE044F40B5B0BC9BA5B20C9C@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: where's the missing power? Date: Sun, 11 Oct 2009 15:54:42 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01CA4A8B.259FCE20" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 091010-0, 10/10/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0007_01CA4A8B.259FCE20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Chris, I didn't think of asking this before but what are the dimensions of the = intake i.e. pipe ID and length of pipe. George (down under)=20 Mike, For what its worth I get full power before the throttle is full open = too and 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 giving 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 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 prop 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 reduction in RPM and fuel flow. Then looked down at = where the throttle was actually set and was shocked to see it slightly = below half open. I dont have a regular manifold pressure gauge, just an = industrial type vacuum gauge ( I really gotta get an MP gauge). Anyway, = the vacuum gauge was indicating 4" of vacuum. So I suspect I am giving up a substantial 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 the 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 it are welcome. Mike Wills RV-4 N144MW ------=_NextPart_000_0007_01CA4A8B.259FCE20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Chris,
I didn't think of asking this = before but what=20 are the dimensions of the intake i.e. pipe ID and length of=20 pipe.
George (down under) 
Mike,
 
For what its worth I get = full power=20 before the throttle is full open too and my intake is the = professionally=20 designed and manufactured Mistral intake.  I have not been = too=20 distracted by it yet and I am not flying and it is giving me about = 6000 rpm=20 static.  Just another data point.
 
All the best,
 
Chris Barber
Houston
From: Rotary motors in aircraft=20 [flyrotary@lancaironline.net] On Behalf Of Mike Wills=20 [rv-4mike@cox.net]
Sent: Saturday, October 10, 2009 10:27=20 PM
To: Rotary motors in aircraft
Subject: = [FlyRotary]=20 where's the missing power?

I noticed quite a while ago and have = mentioned=20 several times here that my engine does not have a linear response to = throttle.=20 It reaches its max power before it reaches fully open throttle. I = havent=20 worried too much about this up until now because the airplane has = sufficient=20 power as is, has slightly better performance than my previous 160HP = Lyc=20 powered -6A, and my wood prop is actually a pretty good match for the = current=20 power level.
 
But I would like to understand what's = going on=20 here and eventually address it. I was flying yesterday, my usual = boring holes=20 in the sky directly over the airport. Decided to investigate just a = little so=20 leveled at 5,000 feet at full throttle. Started reducing throttle = until I=20 noticed a slight reduction in RPM and fuel flow. Then looked down at = where the=20 throttle was actually set and was shocked to see it slightly below = half open.=20 I dont have a regular manifold pressure gauge, just an industrial type = vacuum=20 gauge ( I really gotta get an MP gauge). Anyway, the vacuum gauge was=20 indicating 4" of vacuum.
 
So I suspect I am giving up a = substantial amount=20 of HP. I think the most likely suspect is my throttle body. For a = throttle=20 body I copied Tracy's original design. Started with a stock late = 80s=20 Mazda TB and hacked off the third port and all of the extra stuff. The = cowl in=20 this area is very tight and I am unable to install any sort of air = filter or=20 any sort of bell mouth on the TB. And I'm sure the cowl's close = proximity to=20 the TB influences airflow into it as well.
 
Any comments on this or ways to test = it are=20 welcome.
 
Mike Wills
RV-4=20 N144MW
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