Return-Path: Sender: (Marvin Kaye) To: lml@lancaironline.net Date: Mon, 15 Mar 2004 16:26:02 -0500 Message-ID: X-Original-Return-Path: Received: from rwcrmhc11.comcast.net ([204.127.198.35] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3080114 for lml@lancaironline.net; Mon, 15 Mar 2004 15:36:51 -0500 Received: from MJR (h000094c615c2.ne.client2.attbi.com[65.96.140.242]) by comcast.net (rwcrmhc11) with SMTP id <2004031520361301300ga63fe>; Mon, 15 Mar 2004 20:36:14 +0000 X-Original-Message-ID: <000c01c40ace$018d6180$f28c6041@ne2.client2.attbi.com> From: "Mark Ravinski" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: Hot Start Technique THE WAY THAT WORKED X-Original-Date: Mon, 15 Mar 2004 15:42:16 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0009_01C40AA4.17F716C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0009_01C40AA4.17F716C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable That the engine will fire without fuel pressure is a matter of record. That's why we don't hand turn the prop with hot ignition. Mark Ravinski ----- Original Message -----=20 From: Tubamanflies@aol.com=20 To: Lancair Mailing List=20 Sent: Monday, March 15, 2004 11:28 AM Subject: [LML] Re: Hot Start Technique THE WAY THAT WORKED Responses: George Shattuck: I think what is going on in your case is that you = are cranking until the fuel pressure comes up to give the system the = correct mixture. Then the engine will fire. The open throttle is = probably not improtant because the airflow is determined by cranking = speed on start. But it works so it is the right way to do it. Bob Smiley: I have thought about adding the purge valve but decided to = see if I could come up with a technique that would give consistant = results. It looks like what I have come up with will work but time will = tell. It is an ace in the hole if I need it but it will add complexity. Gary Casey: Again I think the amount of air that the engine gets on = start is a function of cranking speed and very little on throttle = position as long as it is open a little bit. Just watch the manifold = pressure when you crank. Mine hardly changes at all until the engine = fires. Without fuel pressure I don't think you will get a start. If = your system holds pressure on shudown you will get an easier start. If = not you have to crank longer until the vapor is gone and you have liquid = fuel. My boost pump is on the firewall and gets heat soaked also. It = will not pump fuel vapors. The engine pump will and will bring fuel in = until the pressure builds and things cool down. The boost pump will = then help but I usally don't even use it on hot starts. Scott Krueger: If I was flying behind the engine in my Honda Civic = there would be no problem. Return lines give cool fuel and pumps like = to pump cool (liquid) rather than hot (vapor). Some boost pumps like = mine will not pump vapor. Fuel pressure equals start, and because it = is an experimental you have to experment to see what works best. There = are no 2 Lancairs that are the same. The engine driven diaphram pump = will always pump, it is a positive displacement pump. If it gets hot = enough you will start pumping vapor and loose fuel pressure. It will = still pump the vapor but the engine will not run without the right = mixtue. =20 Thanks again to all for the great discussion. Ray ------=_NextPart_000_0009_01C40AA4.17F716C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
That the engine will fire without fuel = pressure is=20 a matter of record.
That's why we don't hand turn the prop = with hot=20 ignition.
 
Mark Ravinski
----- Original Message -----
From:=20 Tubamanflies@aol.com
Sent: Monday, March 15, 2004 = 11:28=20 AM
Subject: [LML] Re: Hot Start = Technique=20 THE WAY THAT WORKED

Responses:

George = Shattuck:  I=20 think what is going on in your case is that you are cranking until the = fuel=20 pressure comes up to give the system the correct mixture.  Then = the=20 engine will fire.  The open throttle is probably not improtant = because=20 the airflow is determined by cranking speed on start.   But = it works=20 so it is the right way to do it.

Bob Smiley: I have thought = about=20 adding the purge valve but decided to see if I could come up with a = technique=20 that would give consistant results.  It looks like what I have = come up=20 with will work but time will tell.  It is an ace in the hole if I = need it=20 but it will add complexity.

Gary Casey: Again I think the = amount of air=20 that the engine gets on start is a function of cranking speed and very = little=20 on throttle position as long as it is open a little bit.  Just = watch the=20 manifold pressure when you crank.  Mine hardly changes at all = until the=20 engine fires.  Without fuel pressure I don't think you will get a = start.=20 If your system holds pressure on shudown you will get an easier = start. =20 If not you have to crank longer until the vapor is gone and you have = liquid=20 fuel.  My boost pump is on the firewall and gets heat soaked = also. =20 It will not pump fuel vapors.  The engine pump will and will = bring fuel=20 in until the pressure builds and things cool down.  The boost = pump will=20 then help but I usally don't even use it on hot starts.

Scott=20 Krueger:  If I was flying behind the engine in my Honda Civic = there would=20 be no problem.  Return lines give cool fuel and pumps like to = pump cool=20 (liquid) rather than hot (vapor).  Some boost pumps like mine = will not=20 pump vapor.   Fuel pressure equals start, and because it is = an=20 experimental you have to experment to see what works best.  There = are no=20 2 Lancairs that are the same.  The engine driven diaphram pump = will=20 always pump,  it is a positive displacement pump.  If it = gets hot=20 enough you will start pumping vapor and loose fuel pressure.  It = will=20 still pump the vapor but the engine will not run without the right=20 mixtue.  

Thanks again to all for the great=20 discussion.

Ray ------=_NextPart_000_0009_01C40AA4.17F716C0--