Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2b1) with ESMTP id 3148567 for flyrotary@lancaironline.net; Tue, 06 Apr 2004 08:20:56 -0400 Received: from EDWARD (clt25-78-058.carolina.rr.com [24.25.78.58]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i36CKrkG012423 for ; Tue, 6 Apr 2004 08:20:54 -0400 (EDT) Message-ID: <002d01c41bd1$9b5d14e0$2402a8c0@EDWARD> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Mazda TB (was: idle speeds) Date: Tue, 6 Apr 2004 08:20:53 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002A_01C41BB0.13FF29A0" 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 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_002A_01C41BB0.13FF29A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Dale, I have flow approx 160 hours with a stripped down stock RX-7 NA = throttle body. Yes, you can ditch everything detachable from the = throttle body as well as take out the "secondary" secondary butterfly = plates - the first set. Depending on whether you want to use both the = secondary and Primary bores you can mill quite a bit off. However, I = did not do that as it was just too convent to attached the air inlet = ducting with the stock bolts. If you check I think you will find that even when the primary butterfly = is fully open, the secondaries have a bit of "lag" and are not 100% = open. I redid that linkage to force the secondary to 100% anytime the = primary was 100%. I also reworked the springs so that should the = throttle cable fail, the butterflys got to full open (WOT) rather than = close as on an automobile. I think Tracy would agree that power does not seem to suffer from using = the "smaller" stock throttle body compared to some of the "Monster" = single throat throttle bodies. I have used both and I agree with Tracy. = I have found no advantage other than saving a small amount of weight = using the larger throttle bodies (that stock TB IS heavy). I also do = not like the momentary "Bog" that occurs when you quickly open a large = throttle body. FWIW Ed Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC ----- Original Message -----=20 From: Dale Rogers=20 To: Rotary motors in aircraft=20 Sent: Monday, April 05, 2004 11:57 PM Subject: [FlyRotary] Mazda TB (was: idle speeds) Hi All, Is anyone on the list using the stock throttle body with the=20 EC2? I've been stripping mine down to repair the fire damage,=20 and it looks like there's a lot on it that isn't needed for=20 aviation operation. In fact, it looks like I could mill away=20 the top 50% of the TB and not impair function at all - except=20 making the intake ducting a little more complex. =20 One thing I'm working on is a simplified version of the EdDIE=20 manifold, with the secondary bores feeding only the secondary=20 ports - rather than just increasing the airflow to a common=20 plenum. Perhaps, it will be easier to get a low speed idle that=20 way. I'm also sticking with the original 6 port manifold base;=20 it's just too tempting to use the secondary power port valve=20 actuator holes for the secondary injectors. What I'm looking for is more information about the upper=20 butterfly assembly in the secondary path. It appears to be=20 a delay mechanism to keep the secondaries from effectively=20 opening during low speed WOT conditions. Can I safety remove=20 it? It seems as though it's not buying me anything in an=20 aviation environment. Thanks, Dale R. COZY MkIV-R #1254 (It is now 20:20 AZ time (23:20 EDT) -------------------------------------------------------------------------= ----- Subject: [FlyRotary] Re: idle speeds (prop stopped flight) Hi Charlie, I had a cruise prop (80 inch pitch) sensenich metal prop on the 6A. = When I was doing engine off glide testing, some thought I would do = better with engine stopped rather than turning. Really had to slow way = down to get prop to stop. Could not measure the difference in glide = engine stopped or windmilling. Really had to go fast, over a hundred to = get it going again! Bernie Kerr, painting the 9A waiting to get rotary back from Bruce T = at SnF A stopped prop is in a complete stall condition, and would be = expected to provide less drag than one that is turning at an RPM of = incipient stall. There will be some RPM for a given pitch and touchdown = speed that will provide the most drag. We just have to figure out what = that is. =20 Landing speed in Kts times 100 gives you ft/min. Pitch divided by = 12 gives you ft/min per revolution of the prop for neutral thrust = (approx.). So my 85 pitch prop at 70 kt landing speed is neutral at = 1000 RPM. So maybe the max drag point is somewhere around 650 RPM (mas = o menos 100). Just a guess. Someone less propeller-design challenged = than I may have a better answer. Al -------------------------------------------------------------------------= ----- >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_002A_01C41BB0.13FF29A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Dale,
 
    I have flow approx = 160 hours=20 with a stripped down stock RX-7 NA throttle body.  Yes, you can = ditch=20 everything detachable from the throttle body as well as take out the = "secondary"=20 secondary butterfly plates - the first set.  Depending on whether = you want=20 to use both the secondary and Primary bores you can mill quite a bit = off. =20 However, I did not do that as it was just too convent to attached the = air inlet=20 ducting with the stock bolts.
 
If you check I think you will find that = even when=20 the primary butterfly is fully open, the secondaries have a bit of "lag" = and are=20 not 100% open.  I redid that linkage to force the secondary to 100% = anytime=20 the primary was 100%.  I also reworked the springs so that should = the=20 throttle cable fail, the butterflys got to full open (WOT) rather than = close as=20 on an automobile.
 
I think Tracy would agree that power = does not seem=20 to suffer from using the "smaller" stock throttle body compared to some = of the=20 "Monster" single throat throttle bodies.  I have used both and I = agree with=20 Tracy.  I have found no advantage other than saving a small amount = of=20 weight using the larger throttle bodies (that stock TB IS = heavy).   I=20 also do not like the momentary "Bog" that occurs when you quickly open a = large=20 throttle body.
 
FWIW
 
Ed
 
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From:=20 Dale = Rogers=20
Sent: Monday, April 05, 2004 = 11:57=20 PM
Subject: [FlyRotary] Mazda TB = (was: idle=20 speeds)

Hi All,

   Is anyone on the list using = the=20 stock throttle body with the
EC2?  I've been stripping mine = down to=20 repair the fire damage,
and it looks like there's a lot on it that = isn't=20 needed for
aviation operation.  In fact, it looks like I = could mill=20 away
the top 50% of the TB and not impair function at all - except =
making the intake ducting a little more complex. =20

   One thing I'm working on is a simplified version = of the=20 EdDIE
manifold, with the secondary bores feeding only the = secondary=20
ports - rather than just increasing the airflow to a common=20
plenum.  Perhaps, it will be easier to get a low speed idle = that=20
way.  I'm also sticking with the original 6 port manifold = base;=20
it's just too tempting to use the secondary power port valve =
actuator=20 holes for the secondary injectors.

   What I'm = looking for is=20 more information about the upper
butterfly assembly in the = secondary=20 path.  It appears to be
a delay mechanism to keep the = secondaries=20 from effectively
opening during low speed WOT conditions.  = Can I=20 safety remove
it?  It seems as though it's not buying me = anything in=20 an
aviation environment.

Thanks,
Dale R.
COZY MkIV-R=20 #1254

(It is now 20:20 AZ time (23:20 EDT)

Subject:=20 [FlyRotary] Re: idle speeds (prop stopped flight)

 

Hi=20 Charlie,

 

I had=20 a cruise prop (80 inch pitch) sensenich metal prop on the 6A. When I = was doing=20 engine off glide testing, some thought I would do better with engine = stopped=20 rather than turning. Really had to slow way down to get prop to stop. = Could=20 not measure the difference in glide engine stopped or windmilling. = Really had=20 to go fast, over a hundred to get it going = again!

 

Bernie = Kerr,=20 painting the 9A waiting to get rotary back from Bruce T at=20 SnF

 

A = stopped prop is=20 in a complete stall condition, and would be expected to provide less = drag=20 than one that is turning at an RPM of incipient stall.  There = will be=20 some RPM for a given pitch and touchdown speed that will provide the = most=20 drag.  We just have to figure out what that is. =20

 

Landing = speed in=20 Kts times 100 gives you ft/min.  Pitch divided by 12 gives you = ft/min=20 per revolution of the prop for neutral thrust (approx.).  So my = 85=20 pitch prop at 70 kt landing speed is neutral at 1000 RPM.  =  So=20 maybe the max drag point is somewhere around 650 RPM (mas o menos = 100).=20  Just a guess.  Someone less propeller-design challenged = than I=20 may have a better answer.

 

Al

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