X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4193164 for flyrotary@lancaironline.net; Fri, 02 Apr 2010 08:12:27 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=oepoZ8SyVIw8kQ/K1Qfc7r3r2iYOgw0fy5I37kOBdfE= c=1 sm=0 a=AH4jwJdKTRcA:10 a=hW/qGz3UojJqX3RcoVWYsQ==:17 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=C_IRinGWAAAA:8 a=YWISOAoqAAAA:8 a=Dm17FUN2X9rsrH5CekoA:9 a=dHEJjCXGi3i4BK7avokA:7 a=blUcU4NqPKf2LOrCRKCZ6nY9acYA:4 a=wPNLvfGTeEIA:10 a=1vhyWl4Y8LcA:10 a=VvPTdWEW8HYA:10 a=EzXvWhQp4_cA:10 a=si9q_4b84H0A:10 a=_jR_I4JzzS9vqV4R:21 a=kXIhfyvPkjOxFT_H:21 a=SSmOFEACAAAA:8 a=RL-ue9UqUvWvhpbzAccA:9 a=1nd8cjLhOlhhnjxbUfIA:7 a=LCL-BhrtIVUSiQQxPqB3_3vM5nQA:4 a=5yX_ujDPNR9zebRG:21 a=ENOMwzF22ov0sPRc:21 a=hW/qGz3UojJqX3RcoVWYsQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 75.191.186.236 Received: from [75.191.186.236] ([75.191.186.236:1063] helo=computername) by cdptpa-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id 03/16-22422-70FD5BB4; Fri, 02 Apr 2010 12:11:51 +0000 From: "Ed Anderson" Message-ID: <03.16.22422.70FD5BB4@cdptpa-omtalb.mail.rr.com> To: "'Rotary motors in aircraft'" Subject: 52mm : [FlyRotary] Re: my weber - dcoe52mm Date: Fri, 2 Apr 2010 08:11:56 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01CAD23C.29328D50" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: AcrSV4d0sHg/+LQxRJ+4Reg94ldoewABQDnQ In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0006_01CAD23C.29328D50 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Kevin, =20 Waaaayyyyy back when, I started out with a Weber TB =96 no jets, but it = had four fuel injector positions. It was dual throat with each throat being 50MM in diameter. After 2 years of flying with it, I took the Weber TB off and build my = own =93Dynamic Chamber=94 intake. Performance improved dramatically. I = went from a top speed of 186 MPH in my RV-6A to 196 MPH and my ROC increased by over = 300 -400 fpm. =20 The lesson I learned was that what was supposed to be the =93cats = Meow=94 for an RX-7 Turning 9000+ rpm did not work well for aircraft application. If = you are using TB with electronic Fuel injection =96 then the diameter is = probably not as critical a factor, but tuning a carb the airflow velocity is much more critical and therefore so is the diameter, ventures, air values, = etc. That is one reason I went with electronic fuel injection =96 I think it = is a whole lot easier to tune than jets. But, if you have an expert (someone = who has done it successfully =96 like Ken Welters) then you may get it = sorted out. =20 But, it does sound like your engine is swallowing too much fuel =96 I = presume you have an air/fuel ratio indictor of some sort? What was it showing = =96 rich? Lean? =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook Sent: Friday, April 02, 2010 7:27 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: my weber - dcoe52mm =20 Welcome to the world of carb tuning. Hopefully Ken or Lynn can point = the way. It took me 2 months of fiddling with the Mikunis to get them right = but that info won't help on the Webbers. Why 52mm? Have you been talking to Paul L? Mighty big for an airplane motor. YMMV Tracy On Fri, Apr 2, 2010 at 12:43 AM, kevin lane wrote: my engine runs, roughly, hard to start, but I can make it run. stock = jets are F7/180 and F8/65. I'd guess these are running quite rich. [went = thru the =BD gallon of fuel really quickly, even tho' engine ran but a few = minutes, max] thought I'd ask the group before I start changing things. ken = welter said he'd help since he's been thru all of this before. I also need to mix up a new batch of fuel. guessed at the first, = because I didn't have a way to measure =BD oz. of oil to add to a =BD gallon of = gas , and probably put WAY too much in. still haven't gotten a timing light to = check how my DIS is actually firing. =20 KevinLane Carpentry www.KevinLaneCarpentry.com =20 ------=_NextPart_000_0006_01CAD23C.29328D50 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Kevin,

 

Waaaayyyyy back when, I started out = with a Weber TB – no jets, but it had four fuel injector positions.=A0 It = was dual throat with each throat being 50MM in = diameter.

After 2 years of flying with it, I = took the Weber TB off and build my own “Dynamic Chamber” = intake.=A0 Performance improved dramatically.=A0 I went from a top speed of 186 MPH = in my RV-6A to 196 MPH and my ROC increased by over 300 -400 = fpm.

 

The lesson I learned was that what = was supposed to be the “cats Meow” for an RX-7 Turning 9000+ rpm = did not work well for aircraft application.=A0 If you are using TB with = electronic Fuel injection – then the diameter is probably not as critical a = factor, but tuning a carb the airflow velocity is much more critical and = therefore so is the diameter, ventures, air values, etc.=A0 That is one reason I went = with electronic fuel injection – I think it is a whole lot easier to = tune than jets.=A0 But, if you have an expert (someone who has done it = successfully – like Ken Welters) then you may get it sorted = out.

 

But, it does sound like your engine = is =A0swallowing too much fuel – I presume you have an air/fuel ratio indictor of = some sort?=A0 What was it showing – rich? = Lean?

 

Ed

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Friday, April 02, = 2010 7:27 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = my weber - dcoe52mm

 

Welcome to the = world of carb tuning.  Hopefully Ken or Lynn can point the way.  It = took me 2 months of fiddling with the Mikunis to get them right but that info = won't help on the Webbers.

Why 52mm? Have you been talking to Paul L?  Mighty big for an = airplane motor.  YMMV

Tracy

On Fri, Apr 2, 2010 at 12:43 AM, kevin lane <n3773@comcast.net> = wrote:

my engine runs, roughly, hard to = start, but I can make it run.  stock jets are F7/180  and F8/65.  = I'd guess these are running quite rich. [went thru the =BD gallon of fuel = really quickly, even tho' engine ran but a few minutes, max]  thought I'd = ask the group before I start changing things.  ken welter said he'd help = since he's been thru all of this before.

I also need to mix up a new batch of fuel.  guessed at the first, because I didn't have a way to measure = =BD oz. of oil to add to a =BD gallon of gas , and probably put WAY too = much in. still haven't gotten a timing light to check how my DIS is actually = firing.

 

KevinLane Carpentry
www.KevinLaneCarpentry.com=

 

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