X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail07.syd.optusnet.com.au ([211.29.132.188] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTPS id 3481932 for flyrotary@lancaironline.net; Sat, 07 Feb 2009 17:01:40 -0500 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.188; envelope-from=lendich@optusnet.com.au Received: from ownerf1fc517b8 (d220-236-255-172.dsl.nsw.optusnet.com.au [220.236.255.172]) by mail07.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id n17M0uvS015285 for ; Sun, 8 Feb 2009 09:00:58 +1100 Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: renesis intake possibility Date: Sun, 8 Feb 2009 08:00:57 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_007E_01C989C3.5FEDAE50" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 0617-3, 04/28/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_007E_01C989C3.5FEDAE50 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Brian, With Ed's help with the maths, I worked out my inlet diameter for my = single development and found 44mm ideal. In most carbs a necking down ( venturi) within the carb increases = velocity - however at what point it becomes a restriction is unknown to = me. I've noticed some slide carbs do away with the venturi for that = reason. So if 44mm is optimum (on paper) and no venturi, anything slightly = smaller will increase velocity for max VE or if unsure do as I do and = stick to 44mm. A smaller runner like Ed uses is better for idle if you stage the = openings as Mazda does. If anyone needs the maths- e-mail me directly and I will pass on my word = doc. George ( down under) lendich@optusnet.com.au ----- Original Message -----=20 From: Bryan Winberry=20 To: Rotary motors in aircraft=20 Sent: Sunday, February 08, 2009 3:42 AM Subject: [FlyRotary] Re: renesis intake possibility Ed, Thanks for your thoughts. I think Tracy just spoke the other day about feeding 4 runners = from 2 mains. So, I thought that using 4 TB's and reducing from 48mm = (1.65in) to 1-1/4 would avoid what you described. Do feel that the reduction ratio had any effect on your = performance? Another plus with setup, is that the fuel rail is on the cold = side of the engine. Which brings up another question. Which is better; = injectors near or far from the port? Discuss, BW =20 --- On Sat, 2/7/09, Ed Anderson = wrote: From: Ed Anderson Subject: [FlyRotary] Re: renesis intake possibility To: "Rotary motors in aircraft" Date: Saturday, February 7, 2009, 10:33 AM Hi Bryan, Welcome. Here is my experience using a TWM throttle body (a = different model than you are looking at). Back in 1992 there was no one = around that I was aware that could provide any answers to what made a = good induction configuration for a flying rotary. So I turned to the = only =93rotary aware=94 crowd around and that was those racing with = rotary engines. So after discussing my needs, I purchase a TWM throttle body = with 4 injector positions. It was a two throat (Webber style) design = with each throat 2=94 in diameter. Two injectors per port (I used MSD = 32 lb/hr injectors that fit the injector holes) for a total of 4 = injectors on the TB. The TWM throttle body was then bolted to a cast = aluminum =93Webber=94 style rotary intake manifold which then took the = two TB channels and divided them into 4 (two primary and two secondary) = distribution runners. I estimate that the best HP I ever made with that set up was = around 130-140HP. My static rpm was 4800 swinging a 68x72 two bladed = wooden prop using the 2.17:1 gear ratio. I later replaced that arrangement with 4 tubes of smaller = diameter (1 =BC=94 for primary and 1 =BD=94 for secondary), made the = runners longer in length and install the stock Mazda 3 port TB which had = considerably smaller openings than the TWM arrangement. I immediately picked up over 300 fpm increase in my ROC and = top speed moved from 186 MPH TAS to 195 MPH TAS. As I learned over the years, it became apparent that what = works great for the racers turning 9000 + rpm may well suck (but may not = suck very well =96 pun intended) at 5000-6000 and was therefore of = questionable use for aircraft. As best I could figure out the problem, = it appears that with the large runner openings and runners that the = mixture velocity in the runners was very much lower than optimum. That = meant the air mass had little momentum and did a poor job of filling the = combustion chambers during the short time they were open. By going to = smaller runners, the mixture velocity increased considerably and = resulted in more mixture in the combustion chamber and more power. Now = if I could of somehow (using a shifting gear box?) have gotten my rpm = range up into the 8000 + range, then that intake system might have been = the cat=92s meow =96 but, of course, I could never get above 4800 rpm = static (and about 5400 once airborne) Now the TWM Throttle body in the photo based on your = description may not have the same problems as it does have a = considerably smaller throat than the one I used. I personally do not = believe the use of the four throats would give you what you are looking = for =96 however, the use of two of the throats (one module) might work. = You could always place your second injectors else where on the secondary = part of the intake. =20 Just my opinion, of course, if the price is really good, you = have little to lose if it doesn=92t work out. I now use a $25 65 mm dia Mustang throttle body which is much = lighter (and much, much cheaper) than the TWM model I purchased back = over 15 years ago. Good luck on your project Ed 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 ---------------------------------------------------------------------- From: Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On Behalf Of Bryan Winberry Sent: Saturday, February 07, 2009 8:57 AM To: Rotary motors in aircraft Subject: [FlyRotary] renesis intake possibility Hello all, I have a chance to purchase a TWM throttle body(see = attch pic) at a very low price. I have a couple questions for the = group. The inlets are 42mm (appx 1.65 in.). Is this too big to = the point that they would be incompatible with the injectors? I plan on = using 1-1/8 and1-1/4 in runners. Also, the bosses are sized for Bosch, Rochestor, or = Lucas injectors. Does this necessarily eliminate my using the stock = Renesis injectors? This setup also would allow the use of a lightweight = airbox thus simplifying the intake system from a manufacturing = standpoint. Thanks in advance, Bryan RV7, Renesis,RD-1C,EC3,EM3 (in the pipeline I hear) =20 =20 ------=_NextPart_000_007E_01C989C3.5FEDAE50 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Brian,
With Ed's help with the maths, I worked = out my=20 inlet diameter for my single development and found 44mm = ideal.
 
In most carbs a necking down ( venturi) = within the=20 carb increases velocity - however at what point it becomes a restriction = is=20 unknown to me. I've noticed some slide carbs do away with the venturi = for that=20 reason.
 
So if 44mm is optimum (on paper) and no = venturi,=20 anything slightly smaller will increase velocity for max VE or if unsure = do as I=20 do and stick to 44mm.
 
A smaller runner like Ed uses is = better for=20 idle if you stage the openings as Mazda does.
 
If anyone needs the maths- e-mail me = directly and I=20 will pass on my word doc.
George ( down under) lendich@optusnet.com.au
----- Original Message -----
From:=20 Bryan Winberry
Sent: Sunday, February 08, 2009 = 3:42=20 AM
Subject: [FlyRotary] Re: = renesis intake=20 possibility

Ed,
Thanks for your thoughts.
I think Tracy just spoke the other day about feeding 4 = runners from=20 2 mains.  So, I thought that using 4 TB's and reducing from = 48mm=20 (1.65in) to 1-1/4 would avoid what you described.
Do feel that the reduction ratio had any effect on your=20 performance?
 
Another plus with setup, is that the fuel rail is on the = cold side=20 of the engine.  Which brings up another = question.  Which=20 is better; injectors near or far from the port?
 
Discuss,
BW  

--- On Sat, 2/7/09, Ed Anderson=20 <eanderson@carolina.rr.com> wrote:
From:=20 Ed Anderson <eanderson@carolina.rr.com>
Subject: = [FlyRotary]=20 Re: renesis intake possibility
To: "Rotary motors in = aircraft"=20 <flyrotary@lancaironline.net>
Date: Saturday, = February 7,=20 2009, 10:33 AM

Hi=20 Bryan,

 

Welcome. =20 Here is my experience using a TWM throttle body (a different = model=20 than you are looking at).  Back in 1992 there was no one = around=20 that I was aware that could provide any answers to what made a = good=20 induction configuration for a flying rotary.  So I turned = to the=20 only =93rotary aware=94 crowd around and that was those racing = with rotary=20 engines.

 

So = after=20 discussing my needs, I purchase a TWM throttle body with 4 = injector=20 positions.  It was a two throat (Webber style) design = with each=20 throat 2=94 in diameter.  Two injectors per port (I used = MSD 32=20 lb/hr injectors that fit the injector holes) for a total of 4=20 injectors on the TB.  The TWM throttle body was then = bolted to a=20 cast aluminum  =93Webber=94 style rotary intake manifold = which then=20 took the two TB channels and divided them into 4 (two primary = and two=20 secondary) distribution runners.

 

I = estimate=20 that the best HP I ever made with that set up was around=20 130-140HP.  My static rpm was 4800 swinging a 68x72 two = bladed=20 wooden prop using the 2.17:1 gear ratio.

 

I = later=20 replaced that arrangement with 4 tubes of smaller diameter (1 = =BC=94 for=20 primary and 1 =BD=94 for secondary), made the runners longer = in length and=20 install the stock Mazda 3 port TB which had considerably = smaller=20 openings than the TWM arrangement.

 

I = immediately=20 picked up over 300 fpm increase in my ROC and top speed moved = from 186=20 MPH TAS to 195 MPH TAS.

 

As = I learned=20 over the years, it became apparent that what works great for = the=20 racers turning 9000 + rpm may well suck (but may not suck very = well =96=20 pun intended)  at 5000-6000 and was therefore of = questionable use=20 for aircraft.  As best I could figure out the problem, it = appears=20 that with the large runner openings and runners that the = mixture=20 velocity in the runners was very much lower than = optimum.  That=20 meant the air mass had little momentum and did a poor job of = filling=20 the combustion chambers during the short time they were = open.  By=20 going to smaller runners, the mixture velocity increased = considerably=20 and resulted in more mixture in the combustion chamber and = more=20 power.   Now if I could of somehow (using a shifting = gear=20 box?) have gotten my rpm range up into the 8000 + range, then = that=20 intake system might have been the cat=92s meow =96 but, of = course, I could=20 never get above 4800 rpm static (and about 5400 once=20 airborne)

 

Now = the TWM=20 Throttle body in the photo based on your description may not = have the=20 same problems as it does have a considerably smaller throat = than the=20 one I used.  I personally do not believe the use of the = four=20 throats would give you what you are looking for =96 however, = the use of=20 two of the throats (one module) might work.  You could = always=20 place your second injectors else where on the secondary part = of the=20 intake. 

 

Just my=20 opinion, of course, if the price is really good, you have = little to=20 lose if it doesn=92t work out.

 

I = now use a=20 $25 65 mm dia Mustang throttle body which is much lighter (and = much,=20 much cheaper) than the TWM model I purchased back over 15 = years=20 ago.

 

Good luck on=20 your project

 

Ed

Ed=20 Anderson
Rv-6A N494BW=20 Rotary Powered
Matthews,=20 NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html<= /DIV>
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
 

From:=20 Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of = Bryan=20 Winberry
Sent:=20 Saturday, February 07, 2009 8:57 AM
To: Rotary motors in=20 aircraft
Subject:=20 [FlyRotary] renesis intake possibility

 

Hello = all,

I have a chance to purchase a = TWM=20 throttle body(see attch pic) at a very low=20 price.  I have a couple questions for the=20 group.

 

The inlets are 42mm (appx 1.65 = in.).  Is this too big to the point that they = would be=20 incompatible with the injectors?  I plan on using = 1-1/8=20 and1-1/4 in runners.

 

Also, the bosses = are sized for=20 Bosch, Rochestor, or Lucas injectors.  Does this=20 necessarily eliminate my using the stock Renesis=20 injectors?

 

This setup also would allow = the use of a=20 lightweight airbox  thus simplifying the = intake system=20 from a manufacturing standpoint.

 

Thanks in=20 advance,

Bryan

RV7, = Renesis,RD-1C,EC3,EM3 (in the=20 pipeline I hear)

 

 

=
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