X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 22 May 2012 09:32:25 -0400 Message-ID: X-Original-Return-Path: Received: from outbound1.exchangedefender.com ([65.99.255.232] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTPS id 5552519 for lml@lancaironline.net; Mon, 21 May 2012 20:45:13 -0400 Received-SPF: none receiver=logan.com; client-ip=65.99.255.232; envelope-from=cberland@systems3.net Received: from remote.systems3.net (wsip-98-172-79-178.ph.ph.cox.net [98.172.79.178]) by outbound1.exchangedefender.com (8.13.8/8.13.1) with ESMTP id q4M0iTEd028772 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=OK) for ; Mon, 21 May 2012 20:44:35 -0400 Received: from S3SBS08SERVER.Systems3.local ([fe80::6077:364b:fa39:c71b]) by S3SBS08SERVER.Systems3.local ([fe80::6077:364b:fa39:c71b%10]) with mapi; Mon, 21 May 2012 17:44:31 -0700 From: Craig Berland X-Original-To: Lancair Mailing List X-Original-Date: Mon, 21 May 2012 17:44:30 -0700 Subject: [LML] 360 still surging Thread-Topic: [LML] 360 still surging Thread-Index: Ac03kMXE0Ti12kS8SVmFvXEKaue5+QAGxxAg X-Original-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_D7A6B5700A0803448C27264F1F5387365B504ABEEAS3SBS08SERVER_" MIME-Version: 1.0 X-ExchangeDefender-Info: Please contact the ISP for more information X-MailScanner-ID: q4M0iTEd028772 X-ExchangeDefender-VirusScan: Found to be clean X-ExchangeDefender-From: cberland@systems3.net X-ExchangeDefender-MagicKey: 1338857075.99802@q6kZCzjHRLI/Wu6ZnAMNNg --_000_D7A6B5700A0803448C27264F1F5387365B504ABEEAS3SBS08SERVER_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Berni, I agree with your diagnosis that fuel vapor is causing your problem. - I am surprised that the fuel pump on low does not solve the prob= lem. It did on my IV-P yesterday after breakfast in Arizona. After a few = minutes the low pump was not required. - The engine mounted pump does not "suck" fuel very well and any v= apor in the line will cause you grief. The engine mounted pump may be gett= ing worn with time and a rebuild may help....I know I am using a lot of "ma= ys". - Some ideas from me... o Make sure the low boost pump is working....turn it on and listen before= starting engine. This is now on my check list. It should help. o If the low boost is running and does not solve the surge problem then t= urn on the high boost and use the mixture knob to get the same fuel rate. L= ean for best idle. o If the engine runs smooth on high boost....then look for air seeping in= to the fuel lines. Look at every joint between the fuel tank(s) and the en= gine mounted fuel pump. If no leaks can be found, I would rebuild the engi= ne mounted pump or even better replace it. Aluminum housings for any kind o= f positive displacement pump is problematic. Just one of many issues.... i= t is possible the bores in your pump are a little too big for the impellers= ...even though they are within print or service tolerance. Heat and low RPM= is the enemy. The impellers are steel and the housing is aluminum. The c= oefficient of thermal expansion is greater for aluminum. The pump's abilit= y to pump is therefore reduced at low RPM when it is hot. - The one caution I would hope to communicate. If this issue is s= omething new, it may be the early warning of an engine pump failure. Craig Berland IV-P N7VG Many of you guys have offered suggestions to help me remedy my ongoing engi= ne surge challenge. As a reminder...my fuel injected IO360 displays a very= pronounced surge during idle and taxi following a flight and brief shutdow= n/restart. The problem never occurs when the engine iis cool. I have tried suggestions such as ground running the engine at 1700 rpm for = extended periods following a restart in an attempt to get some air moving t= hrough the cowl but that has resulted in limited success. So far my only r= emedy is to let the engine sit for a long enough period to let it cool sign= ificantly. If I do, I have zero issues with surging. I even removed my fuel injector servo and sent it off for overhaul (not an = inexpensive undertaking) as another attempt to remedy my problem. That ide= a does not address what I firmly believe to be the problem, heat causing fu= el vapor lock, but I tried it anyway. I reinstalled the servo yesterday an= d test flew. The plane performed flawlessly as it always does following a = first start. When I returned home and let it sit for 20 minutes, restarted= and went to taxi, the surge was just as pronounced as ever. All of my fuel lines are insulated and fire sleeved. The only exposed line= s are the small lines that run up to the spider on the top of the engine. I= do not have any fuel leaks. Turning on my electric fuel pump, while incre= asing fuel pressure from 20 to 25 psi, does not remedy the surge issue. As posted here before I have taken the active and lifted off several times = with this surge issue going on as the surge quits once I apply full throttl= e. As several of you have pointed out this is not a safe way to proceed th= erefore I am again asking for ideas/suggestions from you guys. Many years ago in my drag racing days me and several of my friends would in= stall a cooling can to cool down the fuel and therefore (we believed) helpe= d us produce more power. We would use a coffee can, insert a coil of coppe= r fuel line in the can, put this contraption in line (fuel line) fill it an= d fill it with ice prior to a run. While this is not a practical long term= solution, is this the kind of thing I should be doing to prove/disprove my= belief that I have a vapor lock issue? I sincerely appreciate any and all suggestions! Berni Breen Lancair 360 --_000_D7A6B5700A0803448C27264F1F5387365B504ABEEAS3SBS08SERVER_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Berni,

I agree with your diagnosis that fuel vapor is causing your problem.

-          = I am = surprised that the fuel pump on low does not solve the problem.  It did on my IV-P yesterday after break= fast in Arizona.  After a few = minutes the low pump was not required.

-   &nb= sp;      The engine mounted pump does not “= ;suck” fuel very well and any vapor in the line will cause you grief.=   The engine mounted pump may = be getting worn with time and a rebuild may help….I know I am using a= lot of “mays”.

-     &n= bsp;    Some ideas from me…

o   Make sure the low boost pump is working….turn it= on and listen before starting engine.&nbs= p; This is now on my check list. &n= bsp;It should help.

o   If = the low boost is running and does not solve the surge problem then turn on = the high boost and use the mixture knob to get the same fuel rate. Lean for= best idle.

o   If the engine runs= smooth on high boost….then look for air seeping into the fuel lines.=   Look at every joint between = the fuel tank(s) and the engine mounted fuel pump.  If no leaks can be found, I would rebuild the engine = mounted pump or even better replace it. Aluminum housings for any kind of p= ositive displacement pump is problematic.&= nbsp; Just one of many issues…. it is possible the bores in yo= ur pump are a little too big for the impellers…even though they are w= ithin print or service tolerance. Heat and low RPM is the enemy.  The impellers are steel and the housing= is aluminum.  The coefficient= of thermal expansion is greater for aluminum.  The pump’s ability to pump is therefore reduced at = low RPM when it is hot.

-      =     The one caution I would hope to communicate.  If this issue is something new, it may= be the early warning of an engine pump failure.

Craig Berland=

IV-P N7VG

&nbs= p;

Many of you guys have offered suggestions = to help me remedy my ongoing engine surge challenge.  As a reminder...= my fuel injected IO360 displays a very pronounced surge during idle and tax= i following a flight and brief shutdown/restart.  The problem never oc= curs when the engine iis cool.  

 

I have tried sugges= tions such as ground running the engine at 1700 rpm for extended periods fo= llowing a restart in an attempt to get some air moving through the cowl but= that has resulted in limited success.  So far my only remedy is to le= t the engine sit for a long enough period to let it cool significantly. &nb= sp;If I do, I have zero issues with surging.

=

 

I= even removed my fuel injector servo and sent it off for overhaul (not an i= nexpensive undertaking) as another attempt to remedy my problem.  That= idea does not address what I firmly believe to be the problem, heat causin= g fuel vapor lock, but I tried it anyway.  I reinstalled the servo yes= terday and test flew.  The plane performed flawlessly as it always doe= s following a first start.  When I returned home and let it sit for 20= minutes, restarted and went to taxi, the surge was just as pronounced as e= ver.

 

All of my fuel lines are insulated and fire sl= eeved.  The only exposed lines are the small lines that run up to the = spider on the top of the engine. I do not have any fuel leaks.  Turnin= g on my electric fuel pump, while increasing fuel pressure from 20 to 25 ps= i, does not remedy the surge issue.

 

As posted here = before I have taken the active and lifted off several times with this surge= issue going on as the surge quits once I apply full throttle.  As sev= eral of you have pointed out this is not a safe way to proceed therefore I = am again asking for ideas/suggestions from you guys.

 

Many years ago in my drag racing days me and several of my friends would = install a cooling can to cool down the fuel and therefore (we believed) hel= ped us produce more power.  We would use a coffee can, insert a coil o= f copper fuel line in the can, put this contraption in line (fuel line) fil= l it and fill it with ice prior to a run.  While this is not a practic= al long term solution, is this the kind of thing I should be doing to prove= /disprove my belief that I have a vapor lock issue?

I sincerely appreciate any and all suggestions!=

Berni Breen

<= div>

Lancair 360

 

 




--_000_D7A6B5700A0803448C27264F1F5387365B504ABEEAS3SBS08SERVER_--