X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 23 May 2012 08:17:26 -0400 Message-ID: X-Original-Return-Path: Received: from mail-pz0-f52.google.com ([209.85.210.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTPS id 5554251 for lml@lancaironline.net; Tue, 22 May 2012 17:16:15 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.210.52; envelope-from=bbreen@cableone.net Received: by dano14 with SMTP id o14so8835123dan.25 for ; Tue, 22 May 2012 14:15:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:x-gm-message-state; bh=Gy9yd7GKCDmffqrpWVKH8c4XRzhVyEjwUGkTeK1xFCA=; b=bZF0TsQLJe036sMq7kAFgXtwTZPZFxlBwRvK6Qb+qkXMozQdZgSUI62U4l6HLONpZK 84UZbXz4uPg8R8xZjiwvG7oW1yR3Jguz0AazQTpXMg15hyq4ba4FOD6liR0UoQaa+Sp6 l8R55IMm9c25faCS50wQ4eN3X80xz0q10MedqyOBqTyTt4gxeXM928JdKHz53LckFGMS 93mq5EFm9omr4+jQ4qu5vDulp5SitHSMET3JjBSSeupNwNJac/TlL9q683F6TExo/29x 9o4pXjwnDhwwQrLH4Z9Esqpl7/oSEfVYVEAWKWlea8ft3/25OTdL+er9NmJNxk4CY7bK 8s+w== MIME-Version: 1.0 Received: by 10.68.132.201 with SMTP id ow9mr2285480pbb.160.1337721338838; Tue, 22 May 2012 14:15:38 -0700 (PDT) Received: by 10.68.62.66 with HTTP; Tue, 22 May 2012 14:15:38 -0700 (PDT) In-Reply-To: References: X-Original-Date: Tue, 22 May 2012 16:15:38 -0500 X-Original-Message-ID: Subject: Re: 360 still surging From: Berni Breen X-Original-To: "lml@lancaironline.net" Content-Type: multipart/alternative; boundary=047d7b10ce7935bf9c04c0a68552 X-Gm-Message-State: ALoCoQlpLK4gGpVYBsL420fOzuucYhvuuUK04kJysqf2n5pkGmGdjmQwhs24g37tyRZK8sOobvNc --047d7b10ce7935bf9c04c0a68552 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Hi Bill: No, Lycoming engines do have a fuel return like Continentals do. As such I am trying to figure an effective method to cool my fuel where it is exposed to the heat following an engine shut down. It was suggested to me to pick up some cool air and "blast" it on the engine driven fuel pump. I am in the process of doing that. I am going to remove the fresh air intake for my cabin heater intake, hooking a scat to it (nipple mounted to the front baffle) and routing the scat back to direct the air to blow on my fuel pump. Of course the amount of air will be limited to what the prop creates but it will be an improvement on the existing amount of cool air in the fuel pump area which is zero. Might be an exercise in futility but maybe it will work (?) Additionally (already reported) I am going to pull vacuum on the fuel system to insure I do not have air being introduced somewhere. Thanks for you input. Berni On Tuesday, May 22, 2012, Berni Breen wrote: > Hi Craig: > > I am going to pull vacuum on my fuel system from the servo back to the > fuel selector in an attempt to discover any possible air leaks. > > My issue is not a new one nor does it seem to be worsening. > > I agree with your assessment that my engine driven pump may be a > contributing factor. > > Thanks for your input. > > Berni Breen > Sent from my iPhone > > On May 22, 2012, at 8:32 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 > 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 =93suck=94 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=85.I know I am using a lot = of > =93mays=94.**** > > - Some ideas from me=85**** > > o Make sure the low boost pump is working=85.turn it on and listen befo= re > 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=85.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=85. it is possible the bores in your pump are a little too big for= the > impellers=85even 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=92s 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 fo= r > 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 onl= y > 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 a= n > inexpensive undertaking) as another attempt to remedy my problem. That > idea does not address what I firmly believe to be the problem, heat causi= ng > fuel vapor lock, but I tried it anyway. I reinstalled the servo yesterda= y > and test flew. The plane performed flawlessly as it always does followin= g > 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 sur= ge > issue.**** > > ** ** > > As posted here before I have taken the active and lifted off several time= s > 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 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 practical lo= ng > 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**** > > ** ** > > ** ** > > > > --047d7b10ce7935bf9c04c0a68552 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Hi Bill:

No, Lycoming engines do have a fuel return like= Continentals do. =A0As such I am trying to figure an effective method to c= ool my fuel where it is exposed to the heat following an engine shut down. = =A0It was suggested to me to pick up some cool air and "blast" it= on the engine driven fuel pump. =A0I am in the process of doing that. =A0I= am going to remove the fresh air intake for my cabin heater intake, hookin= g a scat to it (nipple mounted to the front baffle) and routing the scat ba= ck to direct the air to blow on my fuel pump. =A0Of course the amount of ai= r will be limited to what the prop creates but it will be an improvement on= the existing amount of cool air in the fuel pump area which is zero. =A0Mi= ght be an exercise in futility but maybe it will work (?)

Additionally (already reported) I am going to pull vacu= um on the fuel system to insure I do not have air being introduced somewher= e.

Thanks for you input.

Berni

On Tuesday, May 22, 2012, Berni Breen wrote:
Hi Craig:

I am going to pull vacuum on my fuel system from the servo back to the= fuel selector in an attempt to discover any possible air leaks. =A0
<= div>
My issue is not a new one nor does it seem to be worseni= ng.=A0

I agree with your assessment that my engine driven pump= may be a contributing factor.

Thanks for your inp= ut.

Berni Breen
Sent from my iPhone

On May 2= 2, 2012, at 8:32 AM, Craig Berland <cberland@syst= ems3.net> wrote:

Berni,

I agree with your diagnosis that fuel vapor is c= ausing your problem.

= -=A0=A0=A0=A0= =A0=A0=A0=A0=A0 I am surpri= sed that the fuel pump on low does not solve the problem.=A0 I= t did on my IV-P yesterday after breakfast in Arizona.=A0 Afte= r a few minutes the low pump was not required.

-=A0=A0=A0=A0=A0=A0=A0=A0=A0 The engine mounted pump does not =93suck=94 fuel very wel= l and any vapor in the line will cause you grief.=A0 The engin= e mounted pump may be getting worn with time and a rebuild may help=85.I kn= ow I am using a lot of =93mays=94.

-=A0=A0=A0=A0=A0=A0=A0=A0=A0 Some ideas from me=85

o=A0=A0 Make sure the low boost pump is working=85.turn it on and listen befo= re starting engine.=A0 This is now on my check list. =A0= It should help.

o=A0=A0 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=A0=A0 If the engine runs smooth on high boost=85.then look for air seeping = into the fuel lines.=A0 Look at every joint between the fuel t= ank(s) and the engine mounted fuel pump.=A0 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= .=A0 Just one of many issues=85. it is possible the bores in y= our pump are a little too big for the impellers=85even though they are with= in print or service tolerance. Heat and low RPM is the enemy.=A0 The impellers are steel and the housing is aluminum.=A0 The= coefficient of thermal expansion is greater for aluminum.=A0 = The pump=92s ability to pump is therefore reduced at low RPM when it is hot= .

-=A0=A0=A0=A0=A0=A0=A0=A0=A0 The one caution I would hope to communicate.=A0 If this issue is something new, it may be the early warning of an engin= e pump failure.

Craig Berland

IV-P N7VG=

=A0

Many of = you guys have offered suggestions to help me remedy my ongoing engine surge= challenge. =A0As a reminder...my fuel injected IO360 displays a very prono= unced surge during idle and taxi following a flight and brief shutdown/rest= art. =A0The problem never occurs when the engine iis cool. =A0

=A0

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. =A0So far= my only remedy is to let the engine sit for a long enough period to let it= cool significantly. =A0If I do, I=A0have zero issues with surging.<= u>

=A0

I even removed my fuel injector servo and sent it off for ov= erhaul (not an inexpensive undertaking) as another attempt to remedy my pro= blem. =A0That idea does not address what I firmly believe to be the problem= , heat causing fuel vapor lock, but I tried it anyway. =A0I reinstalled the= servo yesterday and test flew. =A0The plane performed flawlessly as it alw= ays does following a first start. =A0When I returned home and let it sit fo= r 20 minutes, restarted and went to taxi, the surge was just as pronounced = as ever.

=A0

All of my fuel lines are insulated and fire sleeved. =A0The = 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. =A0Turning on my electric fue= l pump, while increasing fuel pressure from 20 to 25 psi, does not remedy t= he surge issue.

=A0

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 app= ly full throttle. =A0As several of you have pointed out this is not a safe = way to proceed therefore I am again asking for ideas/suggestions from you g= uys.

=A0

Many years ago in my drag racing days me and several of my f= riends would install a cooling can to cool down the fuel and therefore (we = believed) helped us produce more power. =A0We would use a coffee can, inser= t 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. =A0While this is not a = practical long term solution, is this the kind of thing I should be doing t= o prove/disprove my belief that I have a vapor lock issue?

I sincerely appreciate any and all sugges= tions!

Berni Breen

Lancair 360

=

=A0

=A0




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