X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 22 May 2012 15:27:27 -0400 Message-ID: X-Original-Return-Path: Received: from mail-pb0-f52.google.com ([209.85.160.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTPS id 5553999 for lml@lancaironline.net; Tue, 22 May 2012 15:16:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.160.52; envelope-from=billhogarty@gmail.com Received: by pbbro8 with SMTP id ro8so8871764pbb.25 for ; Tue, 22 May 2012 12:15:43 -0700 (PDT) Received: by 10.68.225.69 with SMTP id ri5mr1418996pbc.147.1337714142946; Tue, 22 May 2012 12:15:42 -0700 (PDT) X-Original-Return-Path: Received: from [192.168.5.34] (ip-64-134-229-95.public.wayport.net. [64.134.229.95]) by mx.google.com with ESMTPS id ru4sm27549031pbc.66.2012.05.22.12.15.38 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 22 May 2012 12:15:40 -0700 (PDT) Subject: Re: [LML] 360 still surging References: From: Bill Hogarty Content-Type: multipart/alternative; boundary=Apple-Mail-40956F0B-404C-4584-8BE5-1DF9857F315E X-Mailer: iPad Mail (9B206) In-Reply-To: X-Original-Message-Id: <56816634-0C1D-4666-A35B-79311643D886@gmail.com> X-Original-Date: Tue, 22 May 2012 12:15:34 -0700 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-40956F0B-404C-4584-8BE5-1DF9857F315E Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Bernie Interesting thread. Does the 360 recycle the fuel back to the tank like the= 4's do? If so, the hot fuel should be replaced with cool fuel assuming you= operate the electric fuel pump long enough. BTW, operating the boost pump o= n low with the engine running just seems to raise the pressure about 2psi. I agree with Craig that a tiny air leak in your fuel lines could be the cul= prit assuming the pump is o.k. In the interim, let the engine cool down....PLEASE. Taking off with a surgi= ng engine is an accident looking for a place to happen. Regards, Bill H. On May 22, 2012, at 6:32 AM, Craig Berland wrote: > 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 pro= blem. It did on my IV-P yesterday after breakfast in Arizona. After a few m= inutes the low pump was not required. > - The engine mounted pump does not =E2=80=9Csuck=E2=80=9D fuel ve= ry well and any vapor in the line will cause you grief. The engine mounted p= ump may be getting worn with time and a rebuild may help=E2=80=A6.I know I a= m using a lot of =E2=80=9Cmays=E2=80=9D. > - Some ideas from me=E2=80=A6 > o Make sure the low boost pump is working=E2=80=A6.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. Le= an for best idle. > o If the engine runs smooth on high boost=E2=80=A6.then look for air see= ping into the fuel lines. Look at every joint between the fuel tank(s) and t= he engine mounted fuel pump. If no leaks can be found, I would rebuild the e= ngine mounted pump or even better replace it. Aluminum housings for any kind= of positive displacement pump is problematic. Just one of many issues=E2=80= =A6. it is possible the bores in your pump are a little too big for the impe= llers=E2=80=A6even though they are within print or service tolerance. Heat a= nd low RPM is the enemy. The impellers are steel and the housing is aluminu= m. The coefficient of thermal expansion is greater for aluminum. The pump=E2= =80=99s 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 s= omething new, it may be the early warning of an engine pump failure. > Craig Berland > IV-P N7VG > =20 > Many of you guys have offered suggestions to help me remedy my ongoing eng= ine 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. =20 > =20 > 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 re= medy is to let the engine sit for a long enough period to let it cool signif= icantly. If I do, I have zero issues with surging. > =20 > 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 fue= l vapor lock, but I tried it anyway. I reinstalled the servo yesterday and t= est flew. The plane performed flawlessly as it always does following a firs= t start. When I returned home and let it sit for 20 minutes, restarted and w= ent to taxi, the surge was just as pronounced as ever. > =20 > All of my fuel lines are insulated and fire sleeved. The only exposed lin= es 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 increa= sing fuel pressure from 20 to 25 psi, does not remedy the surge issue. > =20 > 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 the= refore I am again asking for ideas/suggestions from you guys. > =20 > Many years ago in my drag racing days me and several of my friends would i= nstall 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 copper= fuel line in the can, put this contraption in line (fuel line) fill it and f= ill it with ice prior to a run. While this is not a practical long term sol= ution, is this the kind of thing I should be doing to prove/disprove my beli= ef that I have a vapor lock issue? > I sincerely appreciate any and all suggestions! > Berni Breen > Lancair 360 > =20 > =20 >=20 >=20 >=20 --Apple-Mail-40956F0B-404C-4584-8BE5-1DF9857F315E Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
Bernie

Interesting thread.  Does the 360 recycle the fuel back to the ta= nk like the 4's do?  If so, the hot fuel should be replaced with cool f= uel assuming you operate the electric fuel pump long enough.  BTW, oper= ating the boost pump on low with the engine running just seems to raise the p= ressure about 2psi.

I agree with Craig that a tiny a= ir leak in  your fuel lines could be the culprit assuming the pump is o= .k.

In the interim, let the engine cool down....PLE= ASE.  Taking off with a surging engine is an accident looking for a pla= ce to happen.

Regards, Bill H.


On May 22, 2012, at 6:32 AM, Craig Berland <cberland@systems3.net> wrote:

<= div>

Berni,

I agree with your d= iagnosis that fuel vapor is causing your problem.

-          <= /span>I am surprised that the fuel pump on low do= es not solve the problem.  It d= id on my IV-P yesterday after breakfast in Arizona.  After a few minutes the low pump was not required.

-     &n= bsp;    The engine mounted p= ump does not =E2=80=9Csuck=E2=80=9D fuel very well and any vapor in the line= will cause you grief.  The eng= ine mounted pump may be getting worn with time and a rebuild may help=E2=80=A6= .I know I am using a lot of =E2=80=9Cmays=E2=80=9D.

-         = Some ideas from me=E2=80=A6

o   <= /span>Make sure the low boost pump is working=E2=80=A6.turn it o= n and listen before starting engine.  <= /span>This is now on my check list.  <= /span>It should help.

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

o   If the engine runs smooth on high boost=E2=80=A6.the= n look for air seeping into the fuel lines.=   Look at every joint between the fuel tank(s) and the engine mo= unted fuel pump.  If no leaks c= an be found, I would rebuild the engine mounted pump or even better replace i= t. Aluminum housings for any kind of positive displacement pump is problemat= ic.  Just one of many issues=E2= =80=A6. it is possible the bores in your pump are a little too big for the i= mpellers=E2=80=A6even though they are within print or service tolerance. Hea= t and low RPM is the enemy.  Th= e impellers are steel and the housing is aluminum.  The coefficient of thermal expansion is greater for alu= minum.  The pump=E2=80=99s abil= ity to pump is therefore reduced at low RPM when it is hot.

-       &nb= sp;  The one caution I would hope to c= ommunicate.  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 suggest= ions to help me remedy my ongoing engine surge challenge.  As a reminde= r...my fuel injected IO360 displays a very pronounced surge during idle and t= axi following a flight and brief shutdown/restart.  The problem never o= ccurs when the engine iis cool.  

 

I have tried sug= gestions such as ground running the engine at 1700 rpm for extended periods f= ollowing 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 e= ven removed my fuel injector servo and sent it off for overhaul (not an inex= pensive undertaking) as another attempt to remedy my problem.  That ide= a does not address what I firmly believe to be the problem, heat causing fue= l vapor lock, but I tried it anyway.  I reinstalled the servo yesterday= and test flew.  The plane performed flawlessly as it always does follo= wing 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. &= nbsp;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 el= ectric fuel pump, while increasing fuel pressure from 20 to 25 psi, does not= remedy the surge issue.

 

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

 

Many years= ago in my drag racing days me and several of my friends would install a coo= ling 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 l= ine 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 solu= tion, is this the kind of thing I should be doing to prove/disprove my belie= f that I have a vapor lock issue?

I sincerely appreciate any and all suggestions!

Berni Breen

Lancair 360

&= nbsp;

 

=



= --Apple-Mail-40956F0B-404C-4584-8BE5-1DF9857F315E--