X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 22 May 2012 15:27:28 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-scoter.atl.sa.earthlink.net ([209.86.89.67] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5553364 for lml@lancaironline.net; Tue, 22 May 2012 10:12:18 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.67; envelope-from=panelmaker@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=Nt6wHwEqxS2tfk5tUGOPWj3DPoBR+50N060o93T9IEgbhexAb1O3sUAbD/DBZTzh; h=Received:From:To:References:Subject:Date:Message-ID:MIME-Version:Content-Type:X-Mailer:In-Reply-To:X-MimeOLE:Thread-Index:X-ELNK-Trace:X-Originating-IP; Received: from [209.173.71.64] (helo=COMPUTER1) by elasmtp-scoter.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1SWpoC-000364-5F for lml@lancaironline.net; Tue, 22 May 2012 10:11:32 -0400 From: "Jim Nordin" X-Original-To: "'Lancair Mailing List'" References: Subject: 360 still surging X-Original-Date: Tue, 22 May 2012 09:11:32 -0500 X-Original-Message-ID: <329B010DEEAB407280B42E75FBCCD86A@COMPUTER1> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0076_01CD37FA.E1D448F0" X-Mailer: Microsoft Office Outlook 11 In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Thread-Index: Ac04H2MEOWaXsDYQThyj/x2SlpskJQAAQwGw X-ELNK-Trace: bdfc62829fd2a80cc8ad50643b1069f8239a348a220c2609e8b15951cd738c29d3e206f49a851d2f667c3043c0873f7e350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 209.173.71.64 This is a multi-part message in MIME format. ------=_NextPart_000_0076_01CD37FA.E1D448F0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit I remember seeing a video of a dragster that had problems with fuel supply. The owner used a clear material (plastic of some sort I guess) to see what the fuel looked like in the line as the dragster was needing all available. It showed bubbles. You might do something similar along the fuel line. Use a high fuel pressure clear hose to see if there are bubbles and where they might be coming from. Jim _____ From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Craig Berland Sent: Tuesday, May 22, 2012 8:32 AM To: lml@lancaironline.net Subject: [LML] 360 still surging 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 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 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". - 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 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 positive displacement pump is problematic. Just one of many issues.. it 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 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 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 taxi following a flight and brief shutdown/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 through the cowl but that has resulted in limited success. So far my only remedy is to let the engine sit for a long enough period to let it cool significantly. 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 idea does not address what I firmly believe to be the problem, heat causing fuel vapor lock, but I tried it anyway. I reinstalled the servo yesterday and 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 lines 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 increasing 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 throttle. As several 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) helped us produce more power. We would use a coffee can, insert a coil of copper fuel line in the can, put this contraption in line (fuel line) fill it and 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 ------=_NextPart_000_0076_01CD37FA.E1D448F0 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

I remember seeing a video of a = dragster that had problems with fuel supply. The owner used a clear material = (plastic of some sort I guess) to see what the fuel looked like in the line as the = dragster was needing all available. It showed bubbles. You might do something = similar along the fuel line. Use a high fuel pressure clear hose to see if there = are bubbles and where they might be coming from.

Jim

 

From: = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Craig Berland
Sent: Tuesday, May 22, = 2012 8:32 AM
To: = lml@lancaironline.net
Subject: [LML] 360 still = surging

 

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 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 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”.

-          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 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 positive displacement pump is problematic.  Just one of many issues…. = it 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 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

 

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 taxi following a flight and brief shutdown/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 through the cowl but that has resulted in limited success.  So far = my only remedy is to let the engine sit for a long enough period to let it cool significantly.  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 idea does not address what I firmly believe to be the problem, heat = causing fuel vapor lock, but I tried it anyway.  I reinstalled the servo = yesterday and 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 lines 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 increasing 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 throttle.  As several 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) helped us produce more power.  We would use a coffee can, insert a = coil of copper fuel line in the can, put this contraption in line (fuel line) = fill it and 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

 

 



------=_NextPart_000_0076_01CD37FA.E1D448F0--