X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail12.syd.optusnet.com.au ([211.29.132.193] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTPS id 950451 for flyrotary@lancaironline.net; Thu, 19 May 2005 18:42:59 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.193; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-64-65.dsl.nsw.optusnet.com.au [220.236.64.65]) by mail12.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j4JMg8wZ015581 for ; Fri, 20 May 2005 08:42:09 +1000 Message-ID: <003701c55cc4$a4a37b90$4140ecdc@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: More MAP measurement questions Date: Fri, 20 May 2005 08:46:49 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0034_01C55D18.76062680" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0034_01C55D18.76062680 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageAl, I have been working with 12A's and their combined area is 2.5" with a = 20% increase is 3" - I don't think PL recommended more than a 3" TB for = the 13B, as far as my memory serves me. So a 1.5" per rotor ( or 3" = overall) should be OK. However 2.34 seems a little small for the 13B. George (down under) What's new about this theory? This is what I was telling you a week = or two ago. J I apologize for lack of clarity, causing you to have to re-invent this = theory. Al (Also running TWM TB)=20 That's now the old theory Al. The latest theory is that you and I are = just kidding ourselves, and the restriction is real. I just wish people = like Bill and Bernie would have the decency to lie to me about their = readings :-) =20 Our intake designs are different; so perhaps the concerns are as well. = I have very short runners downstream from the TB, so the MAP reading is = very close to what is seen at the ports. It would be interesting to = know what the MAP reading is near the intake port in a setup like = Tracy's. Whether the MAP reading at the TWM ports is accurate or not, I = don't know. My 44mm diameter barrels (1 per rotor) may be a bit smaller = than I'd like; but I don't think they are causing a significant = performance penalty. The MAP reading is, of course, not the full = measure of the charge into the chamber. There are the pulses and = momentum (velocity) to consider. It might be good to have the TB barrel x-section area roughly matched = to the port area. I can't find my calcs now, but I think the combined = primary and secondary ports on my engine is over 3 sq. in., like maybe = 3.5; and the TB barrel is 2.34 sq. in. So maybe a 20% larger diameter = would give better high end performance, at some expense to throttle = response. I am anxiously awaiting your definitive data on performance vs TB = barrel diameter. J Al ------=_NextPart_000_0034_01C55D18.76062680 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Al,
I have = been working=20 with 12A's and their combined area is 2.5" with a 20% increase is 3" - I = don't=20 think PL recommended more than a 3" TB for the 13B, as far as my memory = serves=20 me. So a 1.5" per rotor ( or 3" overall) should be = OK.
However = 2.34 seems a=20 little small for the 13B.
George = (down=20 under)

What=92s=20 new about this theory?  This is what I was telling you a week or = two ago.=20 J

I=20 apologize for lack of clarity, causing you to have to re-invent this=20 theory.

 

Al=20 (Also running TWM TB) 

 

 

That's=20 now the old theory Al.  The latest theory is that you and I are = just=20 kidding ourselves, and the restriction is real.  I just wish = people like=20 Bill and Bernie would have the decency to lie to me about their = readings=20 :-)  

 

Our intake = designs=20 are different; so perhaps the concerns are as well.  I have very = short=20 runners downstream from the TB, so the MAP reading is very close to = what is=20 seen at the ports.  It would be interesting to know what the MAP = reading=20 is near the intake port in a setup like Tracy=92s.  Whether the=20 MAP reading at the TWM ports is accurate or not, I don=92t know.  = My 44mm=20 diameter barrels (1 per rotor) may be a bit smaller than I=92d like; = but I don=92t=20 think they are causing a significant performance penalty.  The = MAP=20 reading is, of course, not the full measure of the charge into the=20 chamber.  There are the pulses and momentum (velocity) to=20 consider.

 

It might be = good to=20 have the TB barrel x-section area roughly matched to the port = area.  I=20 can=92t find my calcs now, but I think the combined primary and = secondary ports=20 on my engine is over 3 sq. in., like maybe 3.5; and the TB barrel is = 2.34 sq.=20 in.  So maybe a 20% larger diameter would give better high end=20 performance, at some expense to throttle response.

 

I am = anxiously=20 awaiting your definitive data on performance vs TB barrel diameter.=20 J

 

Al

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