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 5.4c3j) with ESMTPS id 4970614 for flyrotary@lancaironline.net; Sun, 08 May 2011 12:24:03 -0400 Received-SPF: none receiver=logan.com; client-ip=129.72.10.32; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht1.uwyo.edu (ponyexpress-ht1.uwyo.edu [10.84.60.208]) by aspensprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id p48GNOjY019863 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Sun, 8 May 2011 10:23:24 -0600 (MDT) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9813:248c:2d68:a28b]) by ponyexpress-ht1 ([10.84.60.208]) with mapi; Sun, 8 May 2011 10:23:24 -0600 From: "Steven W. Boese" To: Rotary motors in aircraft Date: Sun, 8 May 2011 10:23:14 -0600 Subject: RE: [FlyRotary] Re: I've got fuel pressure Thread-Topic: [FlyRotary] Re: I've got fuel pressure Thread-Index: AcwNRCQWKL7Jxc+hT6qmQAN0ym2XPgAU56ZQ Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E1AA3B1AF41D8049B1E3FBD5E2256260088BC0DC63ponyexpressmb_" MIME-Version: 1.0 --_000_E1AA3B1AF41D8049B1E3FBD5E2256260088BC0DC63ponyexpressmb_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Ernest, The results of your injector tests are really interesting. Since 400 squirts of 5 ms gave 15 ml and 400 squirts of 20 ms (exactly 4 ti= mes as long) gave 60 ml (exactly 4 times as much), the missed flow due to t= urn on/ off time (m) is zero. The turn on time and turn off time are both = very unlikely to be zero so the implication is that they are equal. This s= eems unusual to me as I have not seen this in any injectors I've tested. Again, 400 squirts of 5 ms gave 15 ml but 1600 squirts (exactly 4 times as = many) gave 48 and 49 ml (3.2 and 3.3 times as much) where one would have ex= pected 60 ml (exactly 4 times as much). This also seems unusual since chan= ging the number of squirts should not change the injector characteristics. Maybe the MS isn't doing you have told it to do, or there is another parame= ter that is changing. One possibility that comes to mind might be the fuel= pressure not remaining constant during the test. Constant fuel pressure m= ight be something worth verifying since if it is not, the fuel pressure reg= ulator, fuel filter, fuel pump, or other component of the fuel system may b= e at fault. Steve Boese RV6A 1986 13B NA RD1A EC2 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Ernest Christley Sent: Saturday, May 07, 2011 11:50 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: I've got fuel pressure ... The next thing on the agenda was "characterizing" (my term) the injectors. = The Megasquirt has an injector test function. You tell it how long to fir= e the injectors, and how many time. Set it to fire ten times or so for a f= ew milliseconds to verify clickety-click from the injectors, or set up a fi= xture to capture and measure the sprayed fuel, and you should be able to te= ll exactly how the injectors are behaving. I'm not the type to pass up tha= t sort of useless information. s =3D milliseconds sprayed f =3D nominal flow m =3D missed flow due to turn-on/off time c =3D cycles sprayed c(sh-m) =3D measured volume ... The raw numbers from the primary injectors (only one test on the secondari= es, and they looked the same). 400 5ms squirts gave 15ml. 400 20ms squirts gave 60ml. 1600 5ms squirts gave 48ml on one injector and 49ml on the other. --_000_E1AA3B1AF41D8049B1E3FBD5E2256260088BC0DC63ponyexpressmb_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

= Ernest,

 

The results of you= r injector tests are really interesting.

&= nbsp;

Since 400 squirts of 5 ms gave 15 ml and 400 s= quirts of 20 ms (exactly 4 times as long) gave 60 ml (exactly 4 times as mu= ch), the missed flow due to turn on/ off time (m) is zero.  The turn o= n time and turn off time are both very unlikely to be zero so the implicati= on is that they are equal.  This seems unusual to me as I have not see= n this in any injectors I’ve tested.

 

Again, 400 squirts of 5 ms gave 15 ml but 16= 00 squirts (exactly 4 times as many) gave 48 and 49 ml (3.2 and 3.3 times a= s much) where one would have expected 60 ml (exactly 4 times as much). = ; This also seems unusual since changing the number of squirts should not c= hange the injector characteristics.

 =

Maybe the MS isn’t doing you have told it to = do, or there is another parameter that is changing.  One possibility t= hat comes to mind might be the fuel pressure not remaining constant during = the test.  Constant fuel pressure might be something worth verifying s= ince if it is not, the fuel pressure regulator, fuel filter, fuel pump, or = other component of the fuel system may be at fault.

 

 

Steve Boese

= RV6A 1986 13B = NA RD1A EC2

 

 

 

      

 

From: Rotary motors in aircraft [= mailto:flyrotary@lancaironline.net] On Behalf Of Ernest ChristleySent: Saturday, May 07, 2011 11:50 PM
To: Rotary motors i= n aircraft
Subject: [FlyRotary] Re: I've got fuel pressure

…

The next thing on t= he agenda was "characterizing" (my term) the injectors.  The= Megasquirt has an injector test function.  You tell it how long to fi= re the injectors, and how many time.  Set it to fire ten times or so f= or a few milliseconds to verify clickety-click from the injectors, or set u= p a fixture to capture and measure the sprayed fuel, and you should be able= to tell exactly how the injectors are behaving.  I'm not the type to = pass up that sort of useless information.<= br>
s =3D milliseconds sprayed
f =3D nominal flow
m =3D missed flo= w due to turn-on/off time
c =3D cycles sprayed

c(sh-m) =3D  = measured volume

…

The raw numbers f= rom the primary injectors  (only one test on the secondaries, and they= looked the same).

400 5ms squirts gave 15ml.
400 20ms squirts ga= ve 60ml.
1600 5ms squirts gave 48ml on one injector and 49ml on the othe= r.


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