X-Virus-Scanned: clean according to Sophos on Logan.com From: "Christamarmc" Received: from mail-pa0-f41.google.com ([209.85.220.41] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6996239 for flyrotary@lancaironline.net; Wed, 23 Jul 2014 23:33:41 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.220.41; envelope-from=christamarmc@gmail.com Received: by mail-pa0-f41.google.com with SMTP id rd3so3024882pab.0 for ; Wed, 23 Jul 2014 20:33:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:references:from:content-type:in-reply-to:message-id:date:to :content-transfer-encoding:mime-version; bh=7QSMA0YLatRjrpDNumu45pzc0G381QHExMIRDpzIgGE=; b=QVeav0APIKt09r4ADuR8P685gtkqFmwmUYKq24m5gb2eL40vzW+eFeY0G913G8v7tg pc5WAaoJoGrRYYMAep7jRPmzPBpu9lXPpI2aVQc0OuZZJlx/0uR/D9zUMJo3Wf+PAXZs yAb1blnB3iD8OxFDCObm0n2Ia8jYSB/79aAly4My5IS1+3Ot6uXTcgNPaUO74lzEqVzM 5nbgdaW/T/FgYrRrxYKFL5khjI4h7MkDcN9efPaHgNyXfTJ8wgm+5EhF/QlOfVd+TnOX 0S3c5D17noFwXrPfgCqwHZZsp4ElyW0ST7hrlTmhXDttmSkChUnC2S8lTtCjwzL0QE0c f+Xg== X-Received: by 10.68.250.3 with SMTP id yy3mr7133716pbc.56.1406172784864; Wed, 23 Jul 2014 20:33:04 -0700 (PDT) Return-Path: Received: from [192.168.0.3] (234.78.215.218.dyn.commander.net.au. [218.215.78.234]) by mx.google.com with ESMTPSA id y2sm15480053pas.45.2014.07.23.20.33.02 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 23 Jul 2014 20:33:03 -0700 (PDT) Subject: Re: [FlyRotary] Re: Rv7 renises p port References: Content-Type: multipart/alternative; boundary=Apple-Mail-EC46C7AC-A290-4B9C-922A-E0F05E0E00FB X-Mailer: iPad Mail (11D201) In-Reply-To: Message-Id: <9124333C-7EBA-4087-A3FF-5B0AEC76E448@gmail.com> Date: Thu, 24 Jul 2014 13:33:01 +1000 To: Rotary motors in aircraft Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-EC46C7AC-A290-4B9C-922A-E0F05E0E00FB Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Hi james Yes I would have to agree, 0% slip I would guess is no attainable I think fr= om memory around the 3% is the norm but hopefully someone else with more exp= erience on prop design might have a better ideah! the testing I did was at 8= 000 da so I would assume the higher you go the less dense air the more slipp= age, but I could be wrong , I must admit ia don't have a good grasp on prop e= fficiencys as yet, mor trial and error! Cheers Christian Sent from my iPad > On 24 Jul 2014, at 11:14 am, "Patrick Panzera" wrote: >=20 > I wonder how much slip a helicopter has? ;) >=20 >=20 >> On Wed, Jul 23, 2014 at 5:45 PM, James Osborn wrote: >> I don't know jack about slippage, but I think it is the percentage differ= ence between actual distance traveled and theoretical distance traveled if y= our propeller corkscrewed through the air with no thrust. I found a prop sl= ip calculator online and for 86 inch pitch, 2.85 gear ratio, 7000 rpm, 180 m= ph, I get 10% slip. Granted the calculator was for boat propellers, but I d= on't think it matters as long as the units are correct. There has to be som= e slip because there would be no thrust otherwise. So what is considered a r= easonable or good amount of slip? Using Bill's numbers 86 inch pitch, 2.85 g= ear ratio, 7000 rpm, 200 mph, I get 0% slip. That can't be right! >>=20 >>=20 >>> On Fri, Jul 4, 2014 at 7:19 AM, Bill Bradburry wrote: >>> Christian, >>>=20 >>> It seems that you have a lot of prop slippage at cruise. I think that a= t >>> that prop rpm you should be getting 200mph if you had no slippage. >>>=20 >>> Bill >>>=20 >>> -----Original Message----- >>> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] >>> Sent: Thursday, July 03, 2014 4:01 PM >>> To: Rotary motors in aircraft >>> Subject: [FlyRotary] Rv7 renises p port >>>=20 >>> Well hi all >>> Just thought I'd throw out there the mods I,ve done to the renises in an= >>> rv7'. >>> Well the p ported engine is now back in the plane and running well, over= the >>> standard short manifold that was originally in the plane I have gained >>> around 400 static rpm, same prop and gearbox combo, 2.85 ratio, this equ= ates >>> to allot more hp at takeoff, just shy of 2300 prop rpm, I'm running a pr= ince >>> p tip prop at 68" x 86" pitch, >>> At 8000 ft it is turning 7000 at 180 mph tas which is an improvement of 2= 5 >>> mph on previous tests, . So next plan is bigger prop and less pitch to l= et >>> it rev to 7500 in strait and level. >>>=20 >>> Cheers >>> Christian >>> Rv7 renises Aus >>>=20 >>>=20 >>> Sent from my iPad >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: >>> http://mail.lancaironline.net:81/lists/flyrotary/List.html >>>=20 >>>=20 >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/Li= st.html >=20 --Apple-Mail-EC46C7AC-A290-4B9C-922A-E0F05E0E00FB Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Hi james
Yes I would have to= agree, 0% slip I would guess is no attainable I think from memory around th= e 3% is the norm but hopefully someone else with more experience on prop des= ign might have a better ideah! the testing I did was at 8000 da so I would a= ssume the higher you go the less dense air the more slippage, but I could be= wrong , I must admit ia don't have a good grasp on prop efficiencys as yet,= mor trial and error!

Cheers
Christian
Sent from my iPad

On 24 Jul 2014, at 11:14 am, "Patrick P= anzera" <flyrotary@lancair= online.net> wrote:

I wonder how much slip a helicopter has?  ;)


On Wed, Jul 23, 2014 at 5= :45 PM, James Osborn <flyrotary@lancaironline.net> w= rote:
I don't know jack about slipp= age, but I think it is the percentage difference between actual distance tra= veled and theoretical distance traveled if your propeller corkscrewed throug= h the air with no thrust.  I found a prop slip calculator online and fo= r 86 inch pitch, 2.85 gear ratio, 7000 rpm, 180 mph, I get 10% slip.  G= ranted the calculator was for boat propellers, but I don't think it matters a= s long as the units are correct.  There has to be some slip because the= re would be no thrust otherwise.  So what is considered a reasonable or= good amount of slip?  Using Bill's numbers 86 inch pitch, 2.85 gear ra= tio, 7000 rpm, 200 mph, I get 0% slip.  That can't be right!


On Fri, Jul 4,= 2014 at 7:19 AM, Bill Bradburry <flyrotary@lancaironline.net&= gt; wrote:
Christian,

It seems that you have a lot of prop slippage at cruise.  I think that a= t
that prop rpm you should be getting 200mph if you had no slippage.

Bill

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Thursday, July 03, 2014 4:01 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Rv7 renises p port

Well hi all
Just thought I'd throw out there the mods I,ve done to the renises in an
= rv7'.
Well the p ported engine is now back in the plane and running well, over the=
standard short manifold that was originally in the plane I have gained
around 400 static rpm, same prop and gearbox combo, 2.85 ratio, this equates=
to allot more hp at takeoff, just shy of 2300 prop rpm, I'm running a prince=
p tip prop at 68" x 86" pitch,
At 8000 ft it is turning 7000 at 180 mph tas which is an improvement of 25 mph on previous tests, . So next plan is bigger prop and less pitch to let it rev to 7500 in strait and level.

Cheers
Christian
Rv7 renises Aus


Sent from my iPad
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Homepage:  http= ://www.flyrotary.com/
Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html<= br>

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