X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3527963 for flyrotary@lancaironline.net; Wed, 04 Mar 2009 22:50:56 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao106.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090305035019.MMAP22254.fed1rmmtao106.cox.net@fed1rmimpo03.cox.net> for ; Wed, 4 Mar 2009 22:50:19 -0500 Received: from wills ([68.105.85.56]) by fed1rmimpo03.cox.net with bizsmtp id PFqH1b0011CvZmk04FqKkS; Wed, 04 Mar 2009 22:50:19 -0500 X-Authority-Analysis: v=1.0 c=1 a=ebaiju6oyQTCFitnbnUA:9 a=VvdCj-uieYZVd13HbEgA:7 a=3JOGbfHbm4_8N2CFWE7mS1xKH_IA:4 a=XF7b4UCPwd8A:10 a=dH4eYNCgRdT93nL6:21 a=q01zPrwn6479o8x3:21 a=kviXuzpPAAAA:8 a=Ia-xEzejAAAA:8 a=flo2scKpEa_-b4fV_-sA:9 a=nBPhCOH0atUBLBbpXoUA:7 a=33vpLGUMNDuAkSQSzRfMOGFrFWMA:4 a=AfD3MYMu9mQA:10 a=4vB-4DCPJfMA:10 a=EzXvWhQp4_cA:10 a=VcgP0F6yIPTKkxFB:21 a=-STt7uuOvBDSyCtI:21 X-CM-Score: 0.00 Message-ID: <006801c99d45$7f761880$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Fuel economy - Date: Wed, 4 Mar 2009 19:50:16 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0065_01C99D02.71068D40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 This is a multi-part message in MIME format. ------=_NextPart_000_0065_01C99D02.71068D40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable There was an article in the May 2006 issue of Sport Aviation. Two RV-8s = powered by Powersport Rotaries compared to two of Van's factory demo = RV-8s. Time to climb and speeds were pretty comparable. The rotary = powered airplanes were a little heavier. Fuel consumption for a 160 mile = out and return flight the rotaries burned 12.9 and 11.5 gallons while = the Lyc powered RVs burned 8.9 and 9.5 gallons. Cruise portion of the = flight was rotaries 7.85 and 7.1, Lycs 5.05 and 5.45. My guess is that if the pilots could have aggressively leaned the = numbers would be closer but the rotaries were equipped with Powersport's = FADEC. No idea what it does with mixture. Anyway its articles like this that perpetuate the ideas about rotaries = being gas hogs. Until we generate some numbers to contradict, this is = going to be the perception. If you guys generate the numbers I'll = volunteer to write the magazine article! I should also mention that the Powersport RVs looked WAYYYY cooler than = the Lyc powered RVs! Mike Wills RV-4 N144MW ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Wednesday, March 04, 2009 7:27 AM Subject: [FlyRotary] Fuel economy -=20 Mark wrote: Most are just plain scared to run their engines lean of peak where = they are able to get close to the "advertised" bsfc. That seems to be the rule. I chatted yesterday with a hangar neighbor = with his beautiful Lancair Legacy with Continental 550. Does he run = lean of peak? "Eh-h, well, I tried it, but it sounded different, and I = hear the valves don't last as long; so I run it rich of peak. It's a = few more dollars, but cheap insurance" Alcohol and possible vapor lock are the only issues I know of, and = with a properly designed EFI fuel system, vapor lock isn't an issue. As = long as they don't start blending alcohol in the fuel in my neck of the = woods, I'll keep burning mogas and pocketing the difference. =20 I did the ethanol test on my auto fuel yesterday. Within the accuracy = of the test, the fuel had between 4 and 6% ethanol - consistent with = what Mike said regarding CA fuels. So I got out my light and little my = mirror and stiff wire with a sharp end; and inspected my = fiberglass/EZpoxy fuel tanks. No sign of any softening of the surfaces; = no sign of anything happening. Nothing in the fuel filter. So far, so = good. So I'll keep runnin' with auto fuel - certainly when near my home = base. Saves close to $15 for every hour of flying - including the 6 - 8 = cents/ga for the 2-cycle oil (SuperTech 2-stroke oil, $10.97/ga at = Walmart, mix =BE oz per ga.). You stated, "But really the biggest motivation was to do something a = little different." As for that statement... I couldn't agree more, but = how do you quantify something like that? =20 I like to put it differently: "But really the biggest motivation = was to do something a little better."=20 Al G ------=_NextPart_000_0065_01C99D02.71068D40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
There was an article in the May 2006 = issue of Sport=20 Aviation. Two RV-8s powered by Powersport Rotaries compared to two of = Van's=20 factory demo RV-8s. Time to climb and speeds were pretty comparable. The = rotary=20 powered airplanes were a little heavier. Fuel consumption for a 160 mile = out and=20 return flight the rotaries burned 12.9 and 11.5 gallons while the Lyc = powered=20 RVs burned 8.9 and 9.5 gallons. Cruise portion of the flight was = rotaries 7.85=20 and 7.1, Lycs 5.05 and 5.45.
 
 My guess is that if the pilots = could have=20 aggressively leaned the numbers would be closer but the=20 rotaries were equipped with = Powersport's=20 FADEC. No idea what it does with mixture.
 
 Anyway its articles like this = that perpetuate=20 the ideas about rotaries being gas hogs. Until we generate some numbers = to=20 contradict, this is going to be the perception. If you guys generate the = numbers=20 I'll volunteer to write the magazine article!
 
 I should also mention that the = Powersport RVs=20 looked WAYYYY cooler than the Lyc powered RVs!
 
Mike Wills
RV-4 N144MW
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Wednesday, March 04, 2009 = 7:27=20 AM
Subject: [FlyRotary] Fuel = economy -=20

Mark=20 wrote:

Most are just plain scared to = run their=20 engines lean of peak where they are able to get close to the=20 "advertised" bsfc.

 

That = seems to be=20 the rule.  I chatted yesterday with a hangar neighbor with his = beautiful=20 Lancair Legacy with Continental 550.  Does he run lean of peak? = =93Eh-h,=20 well, I tried it, but it sounded different, and I hear the valves = don=92t last=20 as long; so I run it rich of peak.  It=92s a few more dollars, = but cheap=20 insurance=94

 

Alcohol and possible = vapor=20 lock are the only issues I know of, and with a properly = designed EFI=20 fuel system, vapor lock isn't an issue.  As long as they = don't start=20 blending alcohol in the fuel in my neck of the woods, I'll=20 keep burning mogas and pocketing the difference.  =

I did the = ethanol=20 test on my auto fuel yesterday. Within the accuracy of the test, the = fuel had=20 between 4 and 6% ethanol =96 consistent with what Mike said regarding = CA fuels.=20  So I got out my light and little my mirror and stiff wire with a = sharp=20 end; and inspected my fiberglass/EZpoxy fuel tanks. No sign of any = softening=20 of the surfaces; no sign of anything happening. Nothing in the fuel = filter. So=20 far, so good.

So I=92ll = keep=20 runnin=92 with auto fuel =96 certainly when near my home base. =  Saves close=20 to $15 for every hour of flying =96 including the 6 =96 8 cents/ga for = the 2-cycle=20 oil (SuperTech 2-stroke oil, $10.97/ga at Walmart, mix =BE oz per=20 ga.).

 

You stated, "But really the = biggest=20 motivation was to do something a little different."  As for that=20 statement... I couldn't agree more, but how do you quantify something = like=20 that? 

I = like to put=20 it differently: "But really the biggest motivation = was to do=20 something a little better." 

Al=20 = G

 

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