X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 10 Apr 2012 16:07:22 -0400 Message-ID: X-Original-Return-Path: Received: from nm19-vm1.bullet.mail.ne1.yahoo.com ([98.138.91.56] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with SMTP id 5475357 for lml@lancaironline.net; Tue, 10 Apr 2012 09:31:51 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.91.56; envelope-from=casey.gary@yahoo.com Received: from [98.138.90.52] by nm19.bullet.mail.ne1.yahoo.com with NNFMP; 10 Apr 2012 13:31:14 -0000 Received: from [98.138.87.5] by tm5.bullet.mail.ne1.yahoo.com with NNFMP; 10 Apr 2012 13:31:14 -0000 Received: from [127.0.0.1] by omp1005.mail.ne1.yahoo.com with NNFMP; 10 Apr 2012 13:31:14 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 749193.72769.bm@omp1005.mail.ne1.yahoo.com Received: (qmail 72020 invoked by uid 60001); 10 Apr 2012 13:31:14 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=GQquqIGIU6+zRoe0jY1jC8bS84opVbEblQI8n9RXx38tTg6R9HBILxstB4Uu0WdeWLrBssVmyy30Vj3zxkoAKccvScqu87kf+jV3cM39NGX70v+ppM3CJBcF62jUx0Hh63v588fmMY53XlFPeu1Uj2HeVHAukuzdQwdu7pj4BQQ=; X-YMail-OSG: VIjQqm4VM1nrIKEmrAm_AqUVdX.mk14pzuAShsjvVoLe3DM fhTSjHTkPd7OtYTGTnOWxNVxKDkOCG.yzt3sRe2RszppkqWqRoLIo7WcaIcz eix17tgsKgnX9Twr9n4G7KNyyhvasd.2de4RJd.0zuF40WciQ6KGxl4Coa73 a0mV4F2g0btRu_56sRTmjRjmo2V5UwCQHiqnFBwU4G7bhQbpuNnSr07_LLa0 Fai5bF6F3jmvHcP62FK9DrSAN2Rk0MStWcc6pivH.yp5fswK6OL5FEe78n9n T46UsosrbCGHoV6M7Ac.Od2XiIWtaHVjmNQIc.V4IfM4XimfQPyFuudbnNDZ Qrn0Itco.HdZKQ6v.z8FdH_1X70mvBB9HOvOczYON.FBfntpJCGX78VoLMSR eueLOf5y77GY6.Dna3BTSoxdNJhJYWlWB6YWU6CxEVtzRw_elf8WKcp.W5_j 4 Received: from [71.218.233.176] by web125601.mail.ne1.yahoo.com via HTTP; Tue, 10 Apr 2012 06:31:14 PDT X-Mailer: YahooMailWebService/0.8.117.340979 References: X-Original-Message-ID: <1334064674.60439.YahooMailNeo@web125601.mail.ne1.yahoo.com> X-Original-Date: Tue, 10 Apr 2012 06:31:14 -0700 (PDT) From: Gary Casey Reply-To: Gary Casey Subject: Re: Engine "surge" issue X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-1981468715-1589551207-1334064674=:60439" ---1981468715-1589551207-1334064674=:60439 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable The basic design of the Bendix fuel injection system was done before or dur= ing WWII, so I'm surprised that the "designer" is still around. =A0Point is= , it's been here for a long time, although the current configuration was pu= t together in the 50's. =A0And it still works quite well, so I guess that s= ays something.=0A=0ABerni says that his lines are "heat shielded", but I do= n't know exactly what that means. =A0I used the loose-fitting "fire sleeve"= on mine, as I felt it provided better insulation than the integral fire sl= eeves that are sold. =A0The most important fuel line is the one from the fu= el servo to the distributor and it is very important that it be adequately = insulated. =A0The first fuel to vaporize is from the distributor to the inj= ectors, as there is nothing but an orifice at the injector to keep fuel fro= m running out. =A0Then the fuel inside the distributor can vaporize, pushin= g the distributor valve open and pumping more fuel out through the injector= s. =A0finally, the fuel in the line from the servo can vaporize. =A0All tha= t contributes to the rich hot start problem, which occurs with either the "= Bendix" or the Continental system as they are essentially the same in this = area.=0A=0A=0AThe problem Berni describes is after starting when the engine= surges, and that is from a lean condition, either from bubbles in the fuel= going through the injectors, or from a vapor lock of the pump. =A0So after= starting there is almost no way to cure the surge, except to keep the engi= ne running at relaively high load, which increases the fuel flow and reduce= s the time it takes to cool down the fuel system. =A0Leaving the electric p= ump on will usually cure a vapor lock issue, but that isn't the usual cause= (in fact, some airplanes I've flown seemed to be more likely to vapor lock= the electric pump than the mechanical one). =A0One reason to keep the engi= ne running at a reasonably high speed it to keep it from stopping during a = surge condition. =A0Then it is important to avoid any slow idle periods jus= t before takeoff, as vapor can reform during periods of low fuel flow. =A0I= suspect that was the cause of the surge during takeoff.=0A=0AJust some of = my thoughts that I hope help.=0AGary Casey=0A=0A=0ABerni, 100 octane fuel b= oils at a very low temp. Fuel is boiling in the injection lines when the en= gine is hot when you are idling. When you are above idle there is enough fu= el traversing the fuel lines to keep them under the boiling point which is = why you only get this this at idle when the engine is hot.=A0=0A=0AThis was= explained to me by don Rivera at airflow performance, he designed the bend= ix injection system and is the guy who designed the airflow performance sys= tem as well so he knows what he is talking about. This same reason is respo= nsible for the hot start issues in our fuel injection set ups.=0AThis is no= rmal...=0ARandy Snarr=A0=0AN694RS=0A=0A=0ASent from my iPad=0A=0AOn Apr 8, = 2012, at 8:37 PM, Berni Breen wrote:=0A=0A> Whenever = my GAMI injected IO360 powered Lancair 360 is really heated up, following a= flight and only a short time to cool down (less than 30 minutes) and resta= rted, the engine will surge during idle and taxi.=A0 Again this only happen= s when the engine is hot, has been shut down and restarted.=A0 The issue ne= ver occurs when the airplane (engine) is started for the first time on any = given day (super hot day or super cold day).=0A>=A0=0A> Since I feel the is= sue is fuel related I tried leaning and use of the electronic fuel pump dur= ing idle and taxi with zero improvement.=A0 The engine runs very badly with= a pronounced surge.=A0 If I get on the runway and give the engine full thr= ottle, the engine will develop good power and lift off as if there were no = issue...that is until yesterday when the engine just about quit 2000' into = my takeoff roll.=A0 I aborted the takeoff, did some high speed taxiing and = then took off 3 minutes later (no shutdown).=0A>=A0=0A> Today I took off, c= limbed aggressively to get the engine good and hot and landed.=A0 I shutdow= n, let the engine sit for about 10 minutes, restarted and once again experi= enced the surge during idle and or taxiing.=A0 I removed the upper and lowe= r cowl but am still not able to identify the cause of my issue.=0A>=A0=0A> = Clearly I have an issue that is caused by heat affecting fuel.=A0 All of my= fuel lines are heat shielded.=A0 Can anyone offer suggestions or ideas tha= t I can try?=0A>=A0=0A> Berni=0A ---1981468715-1589551207-1334064674=:60439 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
The basic desi= gn of the Bendix fuel injection system was done before or during WWII, so I= 'm surprised that the "designer" is still around.  Point is, it's been= here for a long time, although the current configuration was put together = in the 50's.  And it still works quite well, so I guess that says some= thing.

Berni says that his lines are "heat shielde= d", but I don't know exactly what that means.  I used the loose-fittin= g "fire sleeve" on mine, as I felt it provided better insulation than the i= ntegral fire sleeves that are sold.  The most important fuel line is t= he one from the fuel servo to the distributor and it is very important that= it be adequately insulated.  The first fuel to vaporize is from the d= istributor to the injectors, as there is nothing but an orifice at the injector to keep fuel from running out.  Then the fuel inside the dis= tributor can vaporize, pushing the distributor valve open and pumping more = fuel out through the injectors.  finally, the fuel in the line from th= e servo can vaporize.  All that contributes to the rich hot start prob= lem, which occurs with either the "Bendix" or the Continental system as the= y are essentially the same in this area.

The p= roblem Berni describes is after starting when the engine surges, and that i= s from a lean condition, either from bubbles in the fuel going through the = injectors, or from a vapor lock of the pump.  So after starting there = is almost no way to cure the surge, except to keep the engine running at re= laively high load, which increases the fuel flow and reduces the time it ta= kes to cool down the fuel system.  Leaving the electric pump on will u= sually cure a vapor lock issue, but that isn't the usual cause (in fact, some airplanes I've flown seemed to be more likely to vapor lock the= electric pump than the mechanical one).  One reason to keep the engin= e running at a reasonably high speed it to keep it from stopping during a s= urge condition.  Then it is important to avoid any slow idle periods j= ust before takeoff, as vapor can reform during periods of low fuel flow. &n= bsp;I suspect that was the cause of the surge during takeoff.
Just some of my thoughts that I hope help.
Gary Casey=


Berni, = 100 octane fuel boils at a very low temp. Fuel is boiling in the injection = lines when the engine is hot when you are idling. When you are above idle there is enough fuel traversing the fuel lines to keep them under the boil= ing point which is why you only get this this at idle when the engine is ho= t. =

This was explained to me by don Rivera at ai= rflow performance, he designed the bendix injection system and is the guy w= ho designed the airflow performance system as well so he knows what he is t= alking about. This same reason is responsible for the hot start issues in o= ur fuel injection set ups.
This is= normal...
<= /span>Randy Snarr 
N694RS
=

= Sent from my iPad

On Apr 8, 2012, at 8:37 PM, Berni Breen <bbreen@cableone.net> wrote:

> Whenever my GAMI injected IO360 powered Lancair 360 is really heate= d up, following a flight and only a short time to cool down (less than 30 m= inutes) and restarted, the engine will surge during idle and taxi.  Ag= ain this only happens when the engine is hot, has been shut down and restar= ted.  The issue never occurs when the airplane (engine) is started for= the first time on any given day (super hot day or super cold day).<= span class=3D"Apple-style-span" style=3D"color: rgb(69, 69, 69); font-famil= y: arial, helvetica, sans-serif; font-size: 13px; ">
> 
> Since I feel the issue is fuel related I tried leaning and us= e of the electronic fuel pump during idle and taxi with zero improvement.&n= bsp; The engine runs very badly with a pronounced surge.  If I get on = the runway and give the engine full throttle, the engine will develop good = power and lift off as if there were no issue...that is until yesterday when= the engine just about quit 2000' into my takeoff roll.  I aborted the= takeoff, did some high speed taxiing and then took off 3 minutes later (no= shutdown).
= > 
> Today I took off, climbed aggressively to = get the engine good and hot and landed.  I shutdown, let the engine si= t for about 10 minutes, restarted and once again experienced the surge duri= ng idle and or taxiing.  I removed the upper and lower cowl but am sti= ll not able to identify the cause of my issue.
>&n= bsp;
= > Clearly I have an= issue that is caused by heat affecting fuel.  All of my fuel lines ar= e heat shielded.  Can anyone offer suggestions or ideas that I can try= ?
> 
> Berni
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