X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-yw0-f204.google.com ([209.85.211.204] verified) by logan.com (CommuniGate Pro SMTP 5.3.3) with ESMTP id 4155520 for flyrotary@lancaironline.net; Sun, 07 Mar 2010 15:52:49 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.211.204; envelope-from=wgeslick@gmail.com Received: by ywh42 with SMTP id 42so2495577ywh.7 for ; Sun, 07 Mar 2010 12:52:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=s1JV0p970Cn1AiuMwYAz885A7m8rbY2edfM1GBiB37I=; b=occy2oHOvA7x7jaXV8gpYA5SpoPliKx9MPmBAUp+NzmxEkW1SKs2jR7gutjMVvr57E EEQqyISBLoIRlQXzPozvQap96e/iAIc6DAE6l2OUsRshBEv38ZKvDENRjYjximt/UfY2 spZbQ1np32soKO9i3dp1grJVaNgwXCHRod+AA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=PBCFLqWdF7mfICQZCJ1sjWUQ5XDxu26wL/hl35u5GlEzT8uC20X2dqoHOI4yFJuhCb 54PVw6s5YnTB4Ipo30L9ZuC7LCwZKqs9lAzqPAeubFvW/4HCg6Cb9enizhvToHRuZukT 0imVRV51SkpQCYLfUGH1clxOEqelUvlmswq6c= MIME-Version: 1.0 Received: by 10.101.169.39 with SMTP id w39mr7633504ano.140.1267995133724; Sun, 07 Mar 2010 12:52:13 -0800 (PST) In-Reply-To: References: Date: Sun, 7 Mar 2010 14:52:13 -0600 Message-ID: <3c14c5541003071252x108f3025v780891d0231f616@mail.gmail.com> Subject: Re: [FlyRotary] Re: Performance 68x72 prop. [FlyRotary] Re: TB size, Travel and Power From: Bill Eslick To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001636c5c10a85cb5604813c1f2c --001636c5c10a85cb5604813c1f2c Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable I have been following this thread about the prop modification, and would like to throw my experience (back) in. I have a ground-adjustable Warp Drive 3-blade prop that I bought from Dave Leonard, and also have two wood props. I was also curious about unloading the prop to get more HP, thus more speed. Turns out, I have a virtual brick wall max airspeed with the engine. Here is the data I recorded. It is a little old now, as I have since overhauled the engine with newer higher compression rotors and weights, and produce more power. Also, I use the Felix prop all the time now. The only reason is that the spinner for the Warp prop is 1 inch too small for the cowl, and along with the skinny blades, it looks too much lik= e an ultralight! I guess my vanity lets me put up with a little vibration an= d a little longer takeoff roll. http://www.weslick.com/Prop%20Charts.htm Perhaps someone can tell me why I don't see any more power (speed) at the higher RPM? I suppose Ed will tell me it is due to my intake? Bill Eslick 13B NA RD-1A EC-2 650 HRS **************** I accept that by trimming the prop I can lighten the load and gain some HP (though some here seem to think that HP will increase linearly with RPM to infinity and I don=92t buy that either). But as you alluded to in your previous, there's some potential for mistake in trimming any prop unti= l you are quite sure that you are not HP limited by something other than load= . And I'm not sure yet. Just a feeling based on the fact that I'm using a cut down RX-7 TB that=92s maxed out about 1/3 short of fully open. And honestly= I still havent dug any deeper because the airplane is flying well and has goo= d performance. But sooner or later I'm going to want to get more than the 5700RPM I'm currently getting - I want all the performance that=92s there. --001636c5c10a85cb5604813c1f2c Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
I have been following this thread about the prop modification, and=20 would like to throw my experience (back) in.=A0 I have a ground-adjustable Warp Drive 3-blade prop that I bought from Dave Leonard, and also have=20 two wood props.

I was also curious about unloading the prop to get more HP, thus=20 more speed.=A0 Turns out, I have a virtual brick wall max airspeed with=20 the engine.=A0 Here is the data I recorded.=A0 It is a little old now, as I= =20 have since overhauled the engine with newer higher compression rotors=20 and weights, and produce more power.=A0 Also, I use the Felix prop all the time now.=A0 The only reason is that the spinner for the Warp prop is 1=20 inch too small for the cowl, and along with the skinny blades, it looks=20 too much like an ultralight!=A0 I guess my vanity lets me put up with a=20 little vibration and a little longer takeoff roll.

= http://www.weslick.com/Prop%20Charts.htm

Perhaps someone can tel= l me why I don't see any more power (speed) at the higher RPM?=A0 I sup= pose Ed will tell me it is due to my intake?

Bill Eslick
13B NA=A0 RD-1A EC-2
650 HRS
=A0

****************

I accept that by trimming the prop I can lighten the load and gain some HP (though some here seem to think that HP will increase=20 linearly with RPM to infinity and I don=92t buy that either). But as you alluded to in your=A0previous, there's some potential for mistake in trimming any pro= p until you are quite sure that you are not HP limited by something other=20 than load. And I'm not sure yet. Just a feeling based on the fact that I'= ;m=20 using a cut down RX-7 TB that=92s maxed out about 1/3 short of fully open. And=20 honestly I still havent dug any deeper because the airplane is flying well and has=A0good performance. But sooner or later I'm going to want to get mo= re than the 5700RPM I'm currently getting - I want all the performance=20 that=92s there.

--001636c5c10a85cb5604813c1f2c--