Return-Path: Received: from [203.176.60.254] (HELO app1.nasc.inter.net) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2982379 for flyrotary@lancaironline.net; Sun, 08 Feb 2004 11:58:45 -0500 Received: from ip1-182.eyrkonaeac01.dialup.ca.telus.com ([209.29.80.182] helo=jmosur) by app1.nasc.inter.net with smtp (Exim 3.36 #2) id 1ApsGX-0007LQ-00 for flyrotary@lancaironline.net; Sun, 08 Feb 2004 11:58:42 -0500 From: "Jim Mosur" To: "Rotary motors in aircraft" Subject: RE: [FlyRotary] Re: nonEFI fuel systems Date: Sun, 8 Feb 2004 12:05:37 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0016_01C3EE3B.DD37AB00" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 This is a multi-part message in MIME format. ------=_NextPart_000_0016_01C3EE3B.DD37AB00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit [FlyRotary] Re: nonEFI fuel systemsPaul, You can buy a mixture control from Tom McNeilly, 14001 East Williamsfield Rd., Gilbert Arizona 85296, 480-899-7613, He makes mixture contols for all popular makes of carbs., Holley, Webber etc., all you need is the model number. I bought a mixture contol for a Holley 500 cfm about 5 yrs. ago for $75.00 USD. worked very well, I have since converted to EFI. Jim Mosur RV6 13B C-GAPF -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of sqpilot@earthlink Sent: February 6, 2004 4:14 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: nonEFI fuel systems ----- Original Message ----- From: Ken Welter To: Rotary motors in aircraft Sent: Friday, February 06, 2004 5:55 AM Subject: [FlyRotary] Re: nonEFI fuel systems Hi, Ken....I also have been looking at the Weber carb. Without going into full details, how difficult is it to add a mixture control to the 48 Weber? Thanks in advance for your reply. Paul Conner There are two way to do it, one is with an air bleed system that bleeds air form the intake to the float bole, this is what they use on some snowmobiles and I have not tried this yet on a Weber. The system that I use is an air ram that changes the pressure differential between the float bole and the Venturi. The ram tubes in this photo are positioned about 1.5 inches from the velocity stacks, when the ram is closed the air is drawn only from the air cleaner which is where the float bole vent is, when you open the air ram it increases the air pressure on the Venturi's and the float bole vent pressure that is in the air cleaner remains the same so it draws less fuel. If I start opening the ram at cruise power setting setting the tac will start climbing until it reaches perfect fuel mixture and then it will start to drop as it goes in the lean side and for economy cruise I drop the rpm about 100 rpm on the lean side, depending on altitude at say less than 5000 ft if I open the ram wide open if will kill the engine but at over 12,000 ft it can take all the air without killing it, at 16,000 ft the ram will raise the tac 1000 rpm which is enough difference between holding alt and coming down and I would have never made it up there without the ram. One other thing about the Weber is that its very high tec compared to crude aircraft or American carb's in that it is very adjustable and it is very sensitive to pressure changes, if the air is thinner there is less draw one the main jets so there will be less fuel drawn in. This can be adjusted for the particular engine and application by changing the air correction jets and the emulsion tubes in relation to the main jets, you can go to a smaller main gas jet and a smaller main air and the mixture on the top end will remain the same but it will lean the bottom end and mid range, the emulsion tubes mostly effect the mid range. By jetting down to a smaller air correction jet and smaller main gas jet makes it more sensitive air density and to be honest I don't think the combination the I am currently running is the best as I only have 100 hrs flying on the 48mm where I had 1000 hrs on the 51mm so I had it dialed in much better Ken Hi, Ken....thank you very much for taking the time to both explain your system as well as provide the photo....It's true...a picture IS worth a thousand words! Paul Conner ---------------------------------------------------------------------------- >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0016_01C3EE3B.DD37AB00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [FlyRotary] Re: nonEFI fuel systems
Paul,
 
You=20 can buy a mixture control from Tom McNeilly, 14001 East Williamsfield = Rd.,=20 Gilbert Arizona 85296, 480-899-7613, He makes mixture contols for all = popular=20 makes of carbs., Holley, Webber etc., all you need is the model number. = I bought=20 a mixture contol for a Holley 500 cfm about 5 yrs. ago for $75.00 USD. = worked=20 very well, I have since converted to EFI.
 
 
Jim=20 Mosur
RV6=20 13B
C-GAPF
-----Original Message-----
From: Rotary motors in = aircraft=20 [mailto:flyrotary@lancaironline.net]On Behalf Of=20 sqpilot@earthlink
Sent: February 6, 2004 4:14 = PM
To:=20 Rotary motors in aircraft
Subject: [FlyRotary] Re: nonEFI = fuel=20 systems

 
----- Original Message -----
From:=20 Ken=20 Welter
To: Rotary motors in = aircraft=20
Sent: Friday, February 06, = 2004 5:55=20 AM
Subject: [FlyRotary] Re: = nonEFI fuel=20 systems



Hi, Ken....I also have = been looking=20 at the Weber carb.  Without going into full details, how = difficult=20 is it to add a mixture control to the 48 Weber?   = Thanks in=20 advance for your reply.  Paul = Conner


   There are two way to do it, = one is=20 with an air bleed system that bleeds air form the intake to the = float bole,=20 this is what they use on some snowmobiles and I have not tried this = yet on a=20 Weber.

 The system that I use is an air ram = that=20 changes the pressure differential between the float bole and the=20 Venturi.
 
 The ram tubes in this photo are = positioned=20 about 1.5 inches from the velocity stacks, when the ram is closed = the air is=20 drawn only from the air cleaner which is where the float bole vent = is, when=20 you open the air ram it increases the air pressure on the Venturi's = and the=20 float bole vent pressure that is in the air cleaner remains the same = so it=20 draws less fuel.

If I start opening the ram at cruise = power setting=20 setting the tac will start climbing until it reaches perfect fuel = mixture=20 and then it will start to drop as it goes in the lean side and for = economy=20 cruise I drop the rpm about 100 rpm on the lean side, depending on = altitude=20 at say less than 5000 ft if I open the ram wide open if will kill = the engine=20 but at over 12,000 ft it can take all the air without killing it, at = 16,000=20 ft the ram will raise the tac 1000 rpm which is enough difference = between=20 holding alt and coming down and I would have never made it up there = without=20 the ram.

 One other thing about the Weber is = that its=20 very  high tec compared to crude aircraft or American carb's in = that it=20 is very adjustable and it is very sensitive to pressure changes, if = the air=20 is thinner there is less draw one the main jets so there will be = less fuel=20 drawn in.

 This can be adjusted for the = particular=20 engine and application by changing the air correction jets and the = emulsion=20 tubes in relation to the main jets, you can go to a smaller main gas = jet and=20 a smaller main air and the mixture on the top end will remain the = same but=20 it will lean the bottom end and mid range, the emulsion tubes mostly = effect=20 the mid range.
 
  By jetting down to a smaller air = correction=20 jet and smaller main gas jet makes it more sensitive air density and = to be=20 honest I don't think the combination the I am currently running is = the best=20 as I only have 100 hrs flying on the 48mm where I had 1000 hrs on = the 51mm=20 so I had it dialed in much better
  Ken 
 
Hi, Ken....thank you very much for taking = the time=20 to both explain your system as well as provide the = photo....It's=20 true...a picture IS worth a thousand words! Paul=20 Conner   

>>  Homepage: =20 http://www.flyrotary.com/
>>  Archive:  =20 = http://lancaironline.net/lists/flyrotary/List.html
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