X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 50 [XX] Return-Path: Received: from ms-smtp-04.southeast.rr.com ([24.25.9.103] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1916816 for flyrotary@lancaironline.net; Mon, 12 Mar 2007 12:37:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-04.southeast.rr.com (8.13.6/8.13.6) with SMTP id l2CFd6kH013041 for ; Mon, 12 Mar 2007 11:39:08 -0400 (EDT) Message-ID: <000d01c764bc$97406ec0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: The truth??? / Injector flow rate mystery solved Date: Mon, 12 Mar 2007 11:39:13 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0008_01C7649B.0EAA2A90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0008_01C7649B.0EAA2A90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 23 Sources! Gee, I can't think of that many variables involved {:>). As Tracy stated, fortunately the errors are fairly consistent and = therefore can be "calibrated" out to where the error is less than 1% = (actually much less). So while the issue of accuracy at cruise settings = is a non- issue (in my opinion), the sloppy idle due to excessive fuel = was not such a minor issue. At one time I tried to increase my injectors from the 460 cc/min to the = 550 cc/min and found the idle got so lumpy and sloppy that I had to = switch back - now the reason is a bit clearer why the problem with = idle. Early on after switching to Tracy's EC2 I was using a different = intake/injector set with injectors that flowed around 32 lbs/hour. My = idle was very smooth with those, but decided to use the block holes for = the primary injectors so adopted the Mazda injectors which were rated = for around 42 lbs/hour. My idle was never quite as good as with the = smaller injectors. Actually, probably a good idea to go smaller on the primaries and larger = (if needed) on the secondary injectors. Ed ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Monday, March 12, 2007 10:45 AM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved In a word, Big. But in the end, it really does not matter. Ed and I have found = that after calibration (compensating for all the cumulative errors), the = flow reading error under cruise conditions is insignificant. It might = be intellectually gratifying to know how much error there is in all 23 = sources but that would be time spent not building and not flying. A = bad trade. But if someone wants to hunt them down and report on them, = I'll listen with interest! Tracy (back to working on the -8, and waiting on Bluemountain - = Arrrgghh.....) ----- Original Message -----=20 From: thomas walter=20 To: Rotary motors in aircraft=20 Sent: Monday, March 12, 2007 10:17 AM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved Guys, sorry for the interruption.... How much error is really being seen? =20 Back in my early days at Bosch GmbH (I worked in the IC Center in = Reutlingen, GErmany) on the fuel injectors, and with the BMW system on = calibration. It's been a while, but at the time we had come up with = something like 23 sources of errors on "pulse width" vs. "fuel flow = measurement". =20 Sorry for being such a dummy, but I'm having a hard time trying to = figure out just how much error is involved, and under what rpm range = (idle, cruise, high speed cruise, WOT). =20 Tom Walter (digest mode) -------------------------------------------------------------------------= --- Never miss an email again! Yahoo! Toolbar alerts you the instant new Mail arrives. Check it out. ------=_NextPart_000_0008_01C7649B.0EAA2A90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
23 Sources!  Gee, I can't think of = that many=20 variables involved {:>).
 
As Tracy stated, fortunately the errors = are fairly=20 consistent and therefore can be "calibrated" out to where the error is = less than=20 1% (actually much less).  So while the issue of accuracy at cruise = settings=20 is a non- issue (in my opinion), the sloppy idle due to excessive fuel = was not=20 such a minor issue.
 
At one time I tried to increase my = injectors from=20 the 460 cc/min to the 550 cc/min and found the idle got so lumpy and = sloppy that=20 I had to switch back - now the reason is  a bit clearer why the = problem=20 with idle.
 
Early on after switching to Tracy's EC2 = I was using=20 a different intake/injector set with injectors that flowed around 32=20 lbs/hour.  My idle was very smooth with those, but decided to use = the block=20 holes for the primary injectors so adopted the Mazda injectors which = were rated=20 for around 42 lbs/hour.  My idle was never quite as good as with = the=20 smaller injectors.
 
Actually, probably a good idea to go = smaller on the=20 primaries and larger (if needed) on the secondary = injectors.
 
Ed
----- Original Message -----
From:=20 Tracy = Crook
Sent: Monday, March 12, 2007 = 10:45=20 AM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

In a word, Big.
 
  But in the end, it really does not matter.   Ed = and I=20 have found that after calibration (compensating for all the cumulative = errors), the flow reading error under cruise conditions is=20 insignificant.  It might be intellectually gratifying to know how = much=20 error there is in all 23 sources  but that would be time spent = not=20 building and not flying.  A bad trade.  But if someone wants = to hunt=20 them down and report on them, I'll listen with interest!
 
Tracy (back to working on the -8, and waiting on Bluemountain -=20 Arrrgghh.....)
----- Original Message -----
From: thomas walter
To: Rotary motors in = aircraft=20
Sent: Monday, March 12, 2007 = 10:17=20 AM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

Guys, sorry for the interruption....

How much error is really being seen? 
 
Back in my early days at Bosch GmbH (I worked in the IC Center = in=20 Reutlingen, GErmany) on the fuel injectors, and with the BMW system = on=20 calibration.   It's been a while, but at the time we had = come up=20 with something like 23 sources of errors on "pulse width" vs. "fuel = flow=20 measurement".  
 
Sorry for being such a dummy, but I'm having a hard time trying = to figure out just how much error is involved, and under = what rpm=20 range (idle, cruise, high speed cruise, WOT).  =  
 
Tom Walter
(digest mode)
 
 
 
 
 

Never=20 miss an email again!
Yahoo! Toolbar alerts you the instant = new Mail=20 arrives.=20 Check it out.
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