X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from aspensprings.uwyo.edu ([129.72.10.32] verified) by logan.com (CommuniGate Pro SMTP 6.0c2) with ESMTPS id 5884909 for flyrotary@lancaironline.net; Sat, 17 Nov 2012 11:24:50 -0500 Received-SPF: none receiver=logan.com; client-ip=129.72.10.32; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht3.uwyo.edu (extlb.uwyo.edu [172.26.4.4]) by aspensprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id qAHGO7Mt024857 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Sat, 17 Nov 2012 09:24:07 -0700 (MST) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-hb2.uwyo.edu (10.84.66.36) by ponyexpress-ht3.uwyo.edu (10.84.66.26) with Microsoft SMTP Server (TLS) id 14.2.318.1; Sat, 17 Nov 2012 09:24:06 -0700 Received: from ponyexpress-m10.uwyo.edu ([fe80::60dd:cb9e:6f71:3d48]) by ponyexpress-hb2.uwyo.edu ([fe80::192f:3366:b5f7:608c%13]) with mapi id 14.02.0318.004; Sat, 17 Nov 2012 09:24:06 -0700 From: "Steven W. Boese" To: Rotary motors in aircraft Subject: RE: [FlyRotary] Re: renesis injectors Thread-Topic: [FlyRotary] Re: renesis injectors Thread-Index: AQHNxMmspyPojDJ+fkCJpIPugm1tApfuM1Ew Date: Sat, 17 Nov 2012 16:24:06 +0000 Message-ID: <3E8191F276108F4481AB0721BBA9269E05EBCAF0@ponyexpress-m10.uwyo.edu> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [75.196.153.201] Content-Type: multipart/alternative; boundary="_000_3E8191F276108F4481AB0721BBA9269E05EBCAF0ponyexpressm10u_" MIME-Version: 1.0 --_000_3E8191F276108F4481AB0721BBA9269E05EBCAF0ponyexpressm10u_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed, I used 80% duty cycle as the injector open time at 6500 RPM since my test s= tand could not achieve that RPM the way it was set up. The 80% is often quo= ted as a conservative max duty cycle for reliable injector operation. The= period at 6500 RPM is 9.2 ms so 80% of that is 7.4 ms. 10.6gal/hr * 6500 RPM/ 5265 RPM * 7.4 ms/ 4.4ms =3D 22 gal/hr This estimate is conservative since the effect of the injector dead time is= to make the injector act like a larger one as the pulse width increases. Thanks for looking at this. Steve ________________________________ From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of = Ed Anderson [eanderson@carolina.rr.com] Sent: Saturday, November 17, 2012 6:43 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: renesis injectors Hi Steve, I attempted to verify your math but believe I am missing a cruci= al factor - injector opening time at 6500 rpm Check my math: 10.6 gal/hr =3D 10.6/60 =3D 0.17666 gal/second =3D 0.17666/1000 =3D 0.00017= 666 gal/msec flow for all four injectors combined for an "average" of 0.00017666/4 =3D 0.000044166 gal/msec per single inject= or Taking 0.000044166 * 4(injectors) =3D 0.00017666 gal/msec =3D 0.00017666*10= 00 =3D 0.17666 gal/sec * 60 sec/1 hr =3D 10.596 gal/hr, so that checks Now since there was no different opening times given for the injectors at 6= 500 rpm, I have to assume the opening time was the same as at 5265 rpm (4.4= msec - which is not likely to be correct). But, following this assumption= - then the increase for the flow at 6500 rpm is simply the ratio of 6500= /5265*10.6 gal/hr =3D 13.086 gph a bit short of the 20 gph figure. So , I strongly suspect the injector opening time would increase at the hig= her rpm (it does on my rotary) which would account for the increased flow = - did you happen to measure the injector opening time at 6500 rpm?. Ed From: Steven W. Boese Sent: Saturday, November 17, 2012 1:26 AM To: Rotary motors in aircraft Subject: [FlyRotary] renesis injectors Charlie, My Renesis engine on the test stand uses the same injectors that Richard ha= s. Today, I recorded some data that should indicate whether or not these i= njectors might work for your application. At 23" MAP, fuel pressure of 40 = psi, and 5265 RPM, the fuel flow was 10.6 gal/hr and the pulse width on all= four injectors was 4.4 ms. From this data, it appears that those injector= s should support a fuel flow of slightly over 20 gal/hr at 6500 RPM with an= injector duty cycle of less than 80%. It would be good if you (or anyone = else) would independently check if my calculation is reasonable. Steve Hi Richard, The only info I could find on the green ones seems to indicate that they ar= e 230cc. I can't find numbers for the brown, but based on the model number<= http://lancaironline.net/lists/flyrotary/Message/59224.html?Language=3D#>, = they are probably slightly larger. I suspect, but don't actually know, that= I need 400+cc(normally aspirated Renesis). The yellows are somewhere betwe= en 380 & 430 cc, depending on where you look & what pressure they run at. Thanks for checking, & if it turns out that my research is wrong on the flo= w figures, we'll need to talk further. :-) Charlie Charlie, are you still looking for injectors? Would the ones in the picture of any help? They are out of a 2009 2nd Gen Renesis. The numbers are: green 827 12 , 297= 500-1220 . Brown 827 08 , 297500-1230 . I can not interpret these number. Richard Sohn N2071U No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.2793 / Virus Database: 2629/5892 - Release Date: 11/13/12 --_000_3E8191F276108F4481AB0721BBA9269E05EBCAF0ponyexpressm10u_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Ed,

 

I used 80% duty cycle as the injector open time at 6500 RPM since my tes= t stand could not achieve that RPM the way it was set up. The 80% is o= ften quoted as a conservative max duty cycle for reliable injector operatio= n.   The period at 6500 RPM is 9.2 ms so 80% of that is 7.4 ms. 

 

10.6gal/hr * 6500 RPM/ 5265 RPM * 7.4 ms/ 4.4ms =3D 22 gal/hr

 

This estimate is conservative since the effect of the injector dead time= is to make the injector act like a larger one as the pulse width increases= .

 

Thanks for looking at this.

 

Steve

From: Rotary motors in aircraft [flyrotary= @lancaironline.net] on behalf of Ed Anderson [eanderson@carolina.rr.com] Sent: Saturday, November 17, 2012 6:43 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: renesis injectors

Hi  Steve, I attempted to verify your math b= ut believe I am missing a crucial factor - injector opening time at 6500 rp= m
 
Check my math:
 
10.6 gal/hr =3D 10.6/60 =3D 0.17666 gal/second = =3D 0.17666/1000 =3D 0.00017666 gal/msec flow for all four injectors combin= ed
for an "average" of 0.00017666/4 =3D 0.= 000044166 gal/msec per single injector
 
Taking 0.000044166 * 4(injectors) =3D 0.00017666 = gal/msec =3D 0.00017666*1000 =3D 0.17666 gal/sec * 60 sec/1 hr =3D 10.596 g= al/hr, so that checks
 
 
Now since there was no different opening times gi= ven for the injectors at 6500 rpm, I have to assume the opening time&n= bsp;was the same as at 5265 rpm (4.4 msec - which is not l= ikely to be correct).  But, following this assumption - then the increase for the flow at 6500 rpm is simply the ratio of &= nbsp; 6500/5265*10.6 gal/hr =3D 13.086 gph a bit short of the 20 gph f= igure. 
 
So , I strongly suspect the injector opening time= would increase at the higher rpm (it does on my rotary) which would accoun= t for the increased flow  - did you happen to measure the injector ope= ning time at 6500 rpm?. 
 
Ed
 
Sent: Saturday, November 17, 2012 1:26 AM
Subject: [FlyRotary] renesis injectors

Charlie,

 

My Renesis engine on the test stand uses= the same injectors that Richard has.  Today, I recorded some data tha= t should indicate whether or not these injectors might work for y= our application.  At 23" MAP, fuel pressure of 40 psi, and&n= bsp;5265 RPM, the fuel flow was 10.6 gal/hr and the pulse width on all four injecto= rs was 4.4 ms.  From this data, it appears that those injectors should= support a fuel flow of slightly over 20 gal/hr at 6500 RPM with an injecto= r duty cycle of less than 80%.  It would be good if you (or anyone else) would independently check if my&= nbsp;calculation is reasonable.

 

Steve

 

 

Hi Richard,

The only info I could find on the green ones seems to indicate that they ar= e 230cc. I can't find numbers for the brown, but based on the model number, they are probabl= y slightly larger. I suspect, but don't actually know, that I need 400+cc(normally aspirated Renesis). The yellows are = somewhere between 380 & 430 cc, depending on where you l= ook & what pressure they run at.

Thanks for checking, & if it turns out that= my research is wrong on the flow figures, we'll need to talk further. :-)<= br>
Charlie

Charlie,
are you still looking for injectors?
Would the ones in the picture of any help?
They are out of a 2009 2nd Gen Renesis. The numbers a= re: green 827 12 , 297500-1220 .
Brown 827 08 , 297500-1230 .
I can not = interpret these number.
Richard Sohn
N2071U

No virus found in this message.
Checked by AVG - www.avg.c= om
Version: 2013.0.2793 / Virus Database: 2629/5892 - Release Date: 11/13/12

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