Return-Path: Received: from fed1rmmtao07.cox.net ([68.230.241.32] verified) by logan.com (CommuniGate Pro SMTP 4.2b2) with ESMTP id 3182937 for flyrotary@lancaironline.net; Wed, 21 Apr 2004 13:51:21 -0400 Received: from BigAl ([68.107.116.221]) by fed1rmmtao07.cox.net (InterMail vM.6.01.03.02 201-2131-111-104-20040324) with ESMTP id <20040421175120.CPCH12607.fed1rmmtao07.cox.net@BigAl> for ; Wed, 21 Apr 2004 13:51:20 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: intake ideas? Date: Wed, 21 Apr 2004 10:51:31 -0700 Message-ID: <000001c427c9$477b01d0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C4278E.9B1C29D0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C4278E.9B1C29D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 Al I measure it at the dynamic/plenum chamber, just under the throttle = body. Tracy Hum-m-m. That's about equivalent to me measuring it in the air plenum before the TB. It would be very interesting to know what it is on yours about 4" from the intake port. Then there is the whole question of = 'which' MAP pressure the EC-2 should be interpreting - or maybe it doesn't = matter. . .=20 Al =20 Before the TB? I don't follow you. Ideally, that would be true at WOT only, but it would be a fairly useless figure. And it would definitely matter to the EC2 if you tried to measure MAP there (i.e., Would Not = Work ). Just meant equivalent at WOT, before pressure drop in tubes (my TB is = like a 5" long tube) =20 At one time I did measure the MAP at the far end of the small (primary) runners and found a .8" Hg drop at WOT compared to dynamic chamber = reading.=20 =20 At what RPM? This is really what I was after; a feel for the pressure = drop due to flow losses, and trying to understand the nearly 4" Hg drop from atmospheric that I measured at 6000 rpm. I am pulling both ports = through a 1.75" dia, 5" long TB barrel, and maybe a bit of loss in the inlet = plenum; but not likely that could account for such a large loss. As you = suggested, it must have something to do with the placement of the measurement port. = I may call the guy at TWM and see what his thoughts are. =20 I expected this drop. For reasons of not wanting to enter a prolonged = and fruitless discussion on rotary engine manifold design, I will not = explain why this drop is desirable : ) Oh; come on - gives us the 25 words or less version - well; maybe 50 = words. We promise no prolonged and fruitless discussion. =20 But my main point was that you can get about 2" of MAP increase from ram = air recovery (at ~200 mph), REGARDLESS OF WHERE you measure it. I'm going for that. I've got that ram scoop sticking right out there, = and no air filter to reduce it. =20 Al =20 ------=_NextPart_000_0001_01C4278E.9B1C29D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

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Al

I measure it at the dynamic/plenum chamber, just under the throttle = body.

Tracy

Hum-m-m. = That’s about equivalent to me measuring it in the air plenum = before the TB. It would be very interesting to know what it is on yours = about 4” from the intake port. Then there is the whole question of ‘which’ MAP pressure the EC-2 should be interpreting – = or maybe it doesn’t matter. . .

Al

Before the TB?   I don't follow = you. Ideally, that would be true at WOT only, but it would be a fairly = useless figure. And it would definitely matter to the EC2 if you tried to = measure MAP there (i.e.,  Would Not Work ).

Just meant equivalent at WOT, = before pressure drop in tubes (my TB is like a 5” long = tube)

At one time I did measure the MAP at the = far end of the small (primary) runners and found a .8" Hg drop at WOT = compared to dynamic chamber reading.

At what RPM? This is really what = I was after; a feel for the pressure drop due to flow losses, and trying to understand the nearly 4” Hg drop from atmospheric that I measured = at 6000 rpm. I am pulling both ports through a 1.75” dia, 5” = long TB barrel, and maybe a bit of loss in the inlet plenum; but not likely that = could account for such a large loss. As you suggested, it must have = something to do with the placement of the measurement port. I may call the = guy at TWM and see what his thoughts are.



I expected this drop.  For = reasons of not wanting to enter a prolonged and fruitless discussion on rotary = engine manifold design, I will not explain why this drop is desirable : = )

Oh; come on – gives us the = 25 words or less version – well; maybe 50 words. We promise no = prolonged and fruitless discussion.

But my main point was that you can get about = 2" of MAP increase from ram air recovery (at ~200 = mph),  REGARDLESS OF WHERE you measure it.

I’m going for that. = I’ve got that ram scoop sticking right out there, and no air filter to reduce = it.

Al

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