X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ti-out-0910.google.com ([209.85.142.189] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2724401 for flyrotary@lancaironline.net; Mon, 11 Feb 2008 06:08:55 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.142.189; envelope-from=msteitle@gmail.com Received: by ti-out-0910.google.com with SMTP id b8so214980tic.1 for ; Mon, 11 Feb 2008 03:08:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; bh=NKuchn43iuQL/xHo3hSXXSVOouLUFU5GWFKsZ8MEha8=; b=OJDMCwQsl4DWu1QBJwewUkMo2ZL40lKiKqdQMheF9frdZLTrnfBwu07hXLaHE847/cp0/NWpCZ1OixQj1NwkyrbPedsg6OSCh63IuPcTGFbXeiTE7zs7ZAVtAU2pOygsYOJgMw8syIrZquBXJ1Xn+osk2U9WhyJitwD/zKZaCbQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=qiZL2bpBXnI4TiXkm0pKGwYzHHyeXzHetEDS0s9T5E5CeN3EMj/hoHYYkZ1kMU1+Liexh8jTtl1S6r33v/wmrCKqhE8MHszjW6Vh5YTy2zBxjsr4ZFklwaYLOjQS99+1gDOS2Hcl9W/4t0+7HbKPdcjswvaahsseAPK+RrJGtP0= Received: by 10.110.47.17 with SMTP id u17mr8216103tiu.6.1202728094817; Mon, 11 Feb 2008 03:08:14 -0800 (PST) Received: by 10.70.20.3 with HTTP; Mon, 11 Feb 2008 03:08:14 -0800 (PST) Message-ID: <5cf132c0802110308ybea4ab8wd78c511bae81c8c@mail.gmail.com> Date: Mon, 11 Feb 2008 05:08:14 -0600 From: "Mark Steitle" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Fuel burn In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_20071_22233675.1202728094533" References: ------=_Part_20071_22233675.1202728094533 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Al, I didn't answer your other question. What I suspect is happening is the prop isn't biting until I'm well down the runway. I may want to try a higher rpm (finer pitch) prop setting for takeoff and see how it behaves. Mark On Feb 10, 2008 9:14 PM, Greg Ward wrote: > Yeah, I would be interested in this one too, as I am looking at prop > options too. > Greg > (Lancair, on the ground, in the new shop, mating with a 20B as of this > weekend....(:-) > > ----- Original Message ----- > *From:* Charlie England > *To:* Rotary motors in aircraft > *Sent:* Sunday, February 10, 2008 4:06 PM > *Subject:* [FlyRotary] Re: Fuel burn > > Hi Mark, > > Isn't 7000/2.85=2456.14 ?? > > Is the M/T optimized (diameter, pitch, twist) for turning only 2150rpm? > > Charlie > > > Mark Steitle wrote: > > Al, > > Yes, I'm running one of Tracy's 2.85:1.00 boxes. > > Mark > > On Feb 10, 2008 12:20 PM, Al Gietzen wrote: > > > *Subject:* [FlyRotary] Re: Fuel burn > > > > > > > > Thanks, good data Al. I'm sure that some of the differences we're seeing > > are due to altitude. So far, I've stayed fairly low (3000-5000'). I may > > try some higher altitude flight soon just to see how it changes my > > performance numbers. Another difference is that I have a M/T electric > > constant speed prop. I normally set it to 2150rpm for takeoff. This allows > > the engine to turn around 7000 rpm, which will account some for the higher > > fuel burn I'm seeing. My airport is at 520' msl, so there's a 1000' > > difference there from your 1500' msl airport. Yes, she really accelerates > > down the runway. I'm usually airborne in about 900-1000'. > > > > Mark > > > > I'm not sure I see how these correlate "set it to 2150rpm for takeoff. > > This allows the engine to turn around 7000 rpm,"; but the big difference > > is that you're putting out more horses than I am. At 7000 you're likely > > looking at about 300 hp, so 25-26 gph would be expected. Are you running a > > 2.85 ratio redrive; or something else? > > > > Al > > > > > > > > -- > > Homepage: http://www.flyrotary.com/ > > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html > > ------=_Part_20071_22233675.1202728094533 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Al,
I didn't answer your other question.  What I suspect is happening is the prop isn't biting until I'm well down the runway.  I may want to try a higher rpm (finer pitch) prop setting for takeoff and see how it behaves. 

Mark

On Feb 10, 2008 9:14 PM, Greg Ward <gregw@onestopdesign.biz> wrote:
Yeah, I would be interested in this one too, as I am looking at prop options too.
Greg
(Lancair, on the ground, in the new shop, mating with a 20B as of this weekend....(:-)
----- Original Message -----
Sent: Sunday, February 10, 2008 4:06 PM
Subject: [FlyRotary] Re: Fuel burn

Hi Mark,

Isn't 7000/2.85=2456.14 ??

Is the M/T optimized (diameter, pitch, twist) for turning only 2150rpm?

Charlie


Mark Steitle wrote:
Al,

Yes, I'm running one of Tracy's 2.85:1.00 boxes.

Mark 

On Feb 10, 2008 12:20 PM, Al Gietzen <ALVentures@cox.net> wrote:

Subject: [FlyRotary] Re: Fuel burn

 

Thanks, good data Al. I'm sure that some of the differences we're seeing are due to altitude.  So far, I've stayed fairly low (3000-5000').  I may try some higher altitude flight soon just to see how it changes my performance numbers.  Another difference is that I have a M/T electric constant speed prop.  I normally set it to 2150rpm for takeoff.  This allows the engine to turn around 7000 rpm, which will account some for the higher fuel burn I'm seeing.  My airport is at 520' msl, so there's a 1000' difference there from your 1500' msl airport.  Yes, she really accelerates down the runway.   I'm usually airborne in about 900-1000'. 

Mark

I'm not sure I see how these correlate "set it to 2150rpm for takeoff.  This allows the engine to turn around 7000 rpm,"; but the big difference is that you're putting out more horses than I am.  At 7000 you're likely looking at about 300 hp, so 25-26 gph would be expected.  Are you running a 2.85 ratio redrive; or something else?

Al

 


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