X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 20 Jan 2008 13:48:45 -0500 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 5.2c4) with ESMTP id 2680089 for lml@lancaironline.net; Sat, 19 Jan 2008 22:02:00 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.65; envelope-from=douglasbrunner@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=WmjmKGCMjDR9SEt6AWT2sMPF2xtBPoz6sJELPA+mtYk82iXQP/Dh4I0Pl1/dK8Ti; h=Received:Message-ID:From:To:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [74.93.196.177] (helo=DFWK3391) by elasmtp-kukur.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1JGQQy-0008VU-Li; Sat, 19 Jan 2008 22:01:20 -0500 X-Original-Message-ID: <000e01c85b10$bc526560$1dd0a60a@DFWK3391> From: "Douglas Brunner" X-Original-To: "Mailing List Lancair" Subject: Pressurized Injectors X-Original-Date: Sat, 19 Jan 2008 22:01:21 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01C85AE6.D3138970" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-ELNK-Trace: ad85a799c4f5de37c2eb1477c196d22294f5150ab1c16ac04d04932202c5b85b7b64bda677b646bb0b25fc5600e72005350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 74.93.196.177 This is a multi-part message in MIME format. ------=_NextPart_000_000B_01C85AE6.D3138970 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable A while ago there was a thread on the effect of pressurized injectors = on fuel atomization. It was suggested that pressurizing the injectors = improves fuel atomization and leads to a smoother running engine LOP at = high altitudes. Recently, we ran tests to see what effect the use of Ram Air had on = smoothness of operation at high altitude. Engine: IO-550N, 10:1 compression, ram air, magnetos, GAMI injectors, = GAMI spread of .2 gallons Conditions: Altitude =3D 17,500, OAT =3D 1 C Without Ram Air (MAP =3D 15.2) the engine ran smoothly down to about 60 = deg LOP or 8.8 gal/hr With Ram Air (MAP =3D 16.3) the engine only ran smoothly to Peak or 11.2 = gal/hr The only difference between these two settings (that I can think of) is = that in the first, ambient air pressure is probably slightly above = manifold pressure (accounting for the filter) - which means the injector = is pressurized very slightly. In the second, ambient pressure is = probably about 1.0 less than manifold pressure (accounting for ram = effect) so pressurization of the injector is reversed. This would seem = to confirm the fact that unpressurized injectors reduces fuel = atomization and makes for a rougher running engine LOP at altitude. I would like to run smoothly LOP at altitude using ram air. It seems to = me that I can go ahead and pressurize my injectors by running tubes off = the ram air tube to the injectors and using turbo injectors. (Is Mike = Mahar still selling this setup?) Not sure that I want to go to the = time, trouble and expense to do this though. I am also wondering if using a "hotter" spark from Electronic Ignition = would improve the problem. (I would try to use an Electronic Ignition = system that had the same advance as mags) Your thoughts? ------=_NextPart_000_000B_01C85AE6.D3138970 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

A while ago there was a thread on = the effect=20 of pressurized injectors on fuel atomization. It was suggested = that=20 pressurizing the injectors improves fuel atomization and leads to a = smoother=20 running engine LOP at high altitudes.

Recently, we ran tests to see what = effect the use=20 of Ram Air had on smoothness of operation at high altitude.

Engine: IO-550N, 10:1 compression, = ram air,=20 magnetos, GAMI injectors, GAMI spread of .2 = gallons

Conditions: Altitude=20 =3D 17,500, OAT =3D 1 = C

Without Ram Air (MAP =3D 15.2) the = engine ran=20 smoothly down to about 60 deg LOP or 8.8 gal/hr

With Ram Air (MAP =3D 16.3) the engine = only=20 ran smoothly to Peak or 11.2 gal/hr

The only difference between these = two settings=20 (that I can think of) is that in the first, ambient air = pressure is=20 probably slightly above manifold pressure (accounting for the = filter)=20 - which means the injector is pressurized very slightly. In the = second,=20 ambient pressure is probably about 1.0 less than manifold pressure=20 (accounting for ram effect) so pressurization of the injector is = reversed. =20 This would seem to confirm the fact that unpressurized injectors=20 reduces fuel atomization and makes for a rougher running engine LOP = at=20 altitude.

I would like to run smoothly LOP = at altitude=20 using ram air. It seems to me that I can go ahead and pressurize = my=20 injectors by running tubes off the ram air tube to the injectors and = using turbo=20 injectors. (Is Mike Mahar still selling this setup?) = Not sure=20 that I want to go to the time, trouble and expense to do this=20 though.

I am also wondering if using a "hotter" = spark from=20 Electronic Ignition would improve the problem. (I would try to use = an=20 Electronic Ignition system that had the same advance as = mags)

Your thoughts?

------=_NextPart_000_000B_01C85AE6.D3138970--