X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 31 May 2011 08:16:54 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-kukur.atl.sa.earthlink.net ([209.86.89.65] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4997783 for lml@lancaironline.net; Sun, 29 May 2011 17:25:07 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.65; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=EptOQuL8ry6Cvq615pRMPscziezZEB5iBEpzj5R/VjT5wVpPErWC+5aPXHKAaobb; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.194] (helo=[192.168.1.100]) by elasmtp-kukur.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1QQnTL-00040a-ID for lml@lancaironline.net; Sun, 29 May 2011 17:24:31 -0400 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: multipart/alternative; boundary=Apple-Mail-21--167926903 Subject: Re: [LML] Re: Fuel restriction or air part 2 X-Original-Date: Sun, 29 May 2011 17:24:31 -0400 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <69FC2654-E608-49CA-9649-262DE14DD4B8@earthlink.net> X-Mailer: Apple Mail (2.1082) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940f55f864dacee11021ed2c1c50ce41f45350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.194 --Apple-Mail-21--167926903 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Tom's comment does remind me: after about 50 hours on my IV-P I noticed = one day that the hose insulation going to my gascolator looked ripped. = On closer inspection I determined it had been melted. Looking around I = found no smoke marks but I did determine that the sleeve coupling on the = transfer tube was leaking, blowing hot exhaust on the gascolator. I never had the symptoms you report but I did get a new respect for the = integrity of exhaust systems. (I ended up completely rebuilding mine). Colyn On May 25, 2011, at 7:41 AM, TOM GARDINER wrote: > Berni, > =20 > I am seeing the same symptoms on my aircraft under the same = circumstances but without the engine surging. The fluctuations only = last a few seconds before normal pressure and flow is restored. Turning = on the boost pump briefly will clear the symtoms but the issue will = return after a few minutes. My theory is that the fuel is vaporizing in = the engine driven pump. My crossover exhaust runs under the pump and is = seperated by about 5 inches. I am thinking radiation heating from the = exhaust is the culprit. My plan is to put heat shields on the pipes and = run an air blast to the pump. I wll let you know how this works out > =20 > Tom > =20 > LNC2 51 hrs =20 >=20 > From: Berni > To: lml@lancaironline.net > Sent: Tue, May 24, 2011 12:23:21 PM > Subject: [LML] Fuel restriction or air part 2 >=20 > First of all...thanks to everyone that has tried to help me with my = engine surge (fuel related) problem on my normally aspirated Lancair IV. = I have throughly checked and tested everything suggested so far. There = are no tank vent issues and a vacuum test of the entire system from the = engine driven fuel pump back to the tanks proved there is no air getting = into the system. I even replaced the o rings on the inlet and outlet = sides of the electric fuel pump just to be sure. Unfortunately my test = flight this morning confirmed that the issue still remains. >=20 > This is what happened. On a 50 mile cross country where I took off = and climbed to 7,500 I experienced zero issues. I landed took on some = fuel and took off for home. I climbed to 7,500 again and saw that the = fuel flow and fuel pressure gauges were fluctuating. Since this = occurrence preferred my engine surge problem in the past I knew it was = coming and it did. The engine began surging and continued to do so = until I turned on the electric ( back up) fuel pump. The engine and = gauge readings stabilized immediately. >=20 > So this is where I am...I know I do not have any vacuum (air) leaks = from the tanks through to the engine driven pump, nor do I have any = restrictions in the fuel lines or fuel tank vents. I have replaced my = engine driven pump. All symptoms remain. >=20 > Question...if I am at cruise settings and leaned out reading 16GPH on = the fuel flow and 10PSI on the fuel pressure should this readings rise = when I turn the electric fuel pump on? My GPH goes from 16 to 21 and my = fuel pressure goes from 10 to 15 or higher. >=20 > Sent from my iPad > Berni Breen > Bbreen@cableone.net > -- > For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html --Apple-Mail-21--167926903 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Tom's comment does remind me:  after about 50 = hours on my IV-P I noticed one day that the hose insulation going to my = gascolator looked ripped.  On closer inspection I determined it had = been melted.   Looking around I found no smoke marks but I did = determine that the sleeve coupling on the transfer tube was leaking, = blowing hot exhaust on the gascolator.

I never had = the symptoms you report but I did get a new respect for the integrity of = exhaust systems.  (I ended up completely rebuilding = mine).

Colyn

On May 25, = 2011, at 7:41 AM, TOM GARDINER wrote:

Berni,
I am seeing the same symptoms on = my aircraft under the same circumstances but without the engine = surging.  The fluctuations only last a few seconds before normal = pressure and flow is restored.  Turning on the boost pump briefly = will clear the symtoms but the issue will return after a few = minutes.  My theory is that the fuel is vaporizing in the engine = driven pump.  My crossover exhaust runs under the pump and is = seperated by about 5 inches.  I am thinking radiation = heating from the exhaust is the culprit.  My plan is to put = heat shields on the pipes and run an air blast to the = pump.  I wll let you know how this works out
 
Tom
 
LNC2 51 = hrs  

 Berni= <bbreen@cableone.net>
To: lml@lancaironline.net
Sent: Tue, May 24, 2011 12:23:21 = PM
Subject: [LML] Fuel restriction or = air part 2

First of all...thanks to everyone that has = tried to help me with my engine surge (fuel related) problem on my = normally aspirated Lancair IV.  I have throughly checked and tested = everything suggested so far.  There are no tank vent issues and a = vacuum test of the entire system from the engine driven fuel pump back = to the tanks proved there is no air getting into the system.  I = even replaced the o rings on the inlet and outlet sides of the electric = fuel pump just to be sure.  Unfortunately my test flight this = morning confirmed that the issue still remains.

This is what = happened.  On a 50 mile cross country where I took off and climbed = to 7,500 I experienced zero issues.  I landed took on some fuel and = took off for home.  I climbed to 7,500 again and saw that the fuel = flow and fuel pressure gauges were fluctuating.  Since this = occurrence preferred my engine surge problem in the past I knew it was = coming and it did.  The engine began surging and continued to do so = until I turned on the electric ( back up) fuel pump.  The engine = and gauge readings stabilized immediately.

So this is where I = am...I know I do not have any vacuum (air) leaks from the tanks through = to the engine driven pump, nor do I have any restrictions in the fuel = lines or fuel tank vents.  I have replaced my engine driven = pump.  All symptoms remain.

Question...if I am at cruise = settings and leaned out reading 16GPH on the fuel flow and 10PSI on the = fuel pressure should this readings rise when I turn the electric fuel = pump on?  My GPH goes from 16 to 21 and my fuel pressure goes from = 10 to 15 or higher.

Sent from my iPad
Berni Breen
Bbreen@cableone.net
--
Fo= r archives and unsub http://mail.= lancaironline.net:81/lists/lml/List.html

= --Apple-Mail-21--167926903--