Return-Path: Received: from fed1rmmtao08.cox.net ([68.230.241.31] verified) by logan.com (CommuniGate Pro SMTP 4.2) with ESMTP id 382282 for flyrotary@lancaironline.net; Sat, 28 Aug 2004 12:33:15 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.31; envelope-from=daveleonard@cox.net Received: from davidandanne ([68.111.224.107]) by fed1rmmtao08.cox.net (InterMail vM.6.01.03.02.01 201-2131-111-104-103-20040709) with SMTP id <20040828163222.DUF252.fed1rmmtao08.cox.net@davidandanne> for ; Sat, 28 Aug 2004 12:32:22 -0400 From: "DaveLeonard" To: "Rotary motors in aircraft" Subject: RE: [FlyRotary] Re: Engine run-vacuum accumilator Date: Sat, 28 Aug 2004 09:32:23 -0700 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0022_01C48CE1.EC9F0030" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) In-Reply-To: Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 This is a multi-part message in MIME format. ------=_NextPart_000_0022_01C48CE1.EC9F0030 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Al, I think you are Ok measuring at the intake ports. My two computers use the two extremes. My system: Controller A: uses the stock intake manifold MAP port which is actually inside the stock fuel injector bores on the center housing. You cant get any closer than that. This MAP line is T'd with the fuel pressure regulator and the sensor for the engine monitor. Controller B: uses the TWM MAP ports which are just down stream of the TB valve and upstream of very long runners (about 28" - because that's how I could get everything to fit). The MAP line is T'd to both runners and to the BOV. Controller A, the closer one, actually works best for idle, Controller B seems to work best for lean cruise (another area where rough running issues begin to pop up). At first the difference was fairly significant, but now both controllers are nearly equal so I think maybe I am only imagining the difference. Now that I think about it. Adding the BOV really seemed to improve the idle performance of controller B. That is, adding another foot of MAP line with a small chamber at the end made controller B idle as well as controller A, which already had an extra foot of line going to a small chamber in the fuel pressure regulator and another to the MAP sensor for the engine monitor. During testing, I could not get the engine to run well at all if the MAP lines were only connected to just one of the TWM ports. Now that I look back and add it all up, I think the jet/filter idea is the way to go. Probably just the filter would be enough and easier to install. Who tossed in that idea, was it Bulent? Dave Leonard Hi Al, Here's a clip from I email exchange I had with Tracy a while back. For me the trick to getting a smooth idle and a balanced mixture between rotors at high power was to measure the MAP right behind the throttle body so to minimized the effect of the pulses in the runners. The MAP ports are just downstream from the TB. The difference is that Tracy's TB is way out there BEFORE the runners. Mine are about 5" from the rotor housing, and downstream from what are effectively short runners - the TB barrels. I guess it could be that there is very short term variations in the MAP readings. Is there a pattern here? Are all those of us seeing rough low-MAP issues measuring MAP nearer the intake ports? Let's see; Rusty, Dave. . . who else? Al ------=_NextPart_000_0022_01C48CE1.EC9F0030 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Al, I = think you are=20 Ok measuring at the intake ports. My two computers use the two=20 extremes. My system:

Controller A:=20 uses the stock intake manifold MAP port which is actually inside the = stock fuel=20 injector bores on the center housing. You cant get any closer than = that. This MAP line is T'd with the fuel pressure regulator and = the sensor=20 for the engine monitor.

Controller B: uses=20 the TWM MAP ports which are just down stream of the TB valve and = upstream of=20 very long runners (about 28" - because that's how I could get everything = to=20 fit). The MAP line is T'd to both runners and to the=20 BOV.

Controller A, the=20 closer one, actually works best for idle, Controller B seems to work = best for=20 lean cruise (another area where rough running issues begin to pop = up). At=20 first the difference was fairly significant, but now both controllers = are nearly=20 equal so I think maybe I am only imagining the = difference.

Now = that I think=20 about it. Adding the BOV really seemed to improve the idle = performance of=20 controller B. That is, adding another foot of MAP line with a = small=20 chamber at the end made controller B idle as well as controller A, which = already=20 had an extra foot of line going to a small chamber in the fuel pressure=20 regulator and another to the MAP sensor for the engine=20 monitor.

During testing, I=20 could not get the engine to run well at all if the MAP lines were only = connected=20 to just one of the TWM ports. Now that I look back and add it = all up,=20 I think the jet/filter idea is the way to go. Probably just the = filter=20 would be enough and easier to install. Who tossed in that idea, = was it=20 Bulent?

Dave=20 Leonard

Hi Al,

Here's a clip from I email exchange I had = with=20 Tracy a while back. For

me the trick to getting a smooth idle and a = balanced=20 mixture between

rotors at high power was to measure the MAP = right=20 behind the throttle

body so to minimized the effect of the = pulses in the=20 runners.

The MAP ports are just = downstream from the TB. The difference is that = Tracy’s TB is way = out there BEFORE=20 the runners. Mine are about 5” from the rotor housing, and = downstream=20 from what are effectively short runners – the TB barrels. = I guess it=20 could be that there is very short term variations in the MAP=20 readings.

Is there = a pattern=20 here? Are all those of us seeing rough low-MAP issues measuring = MAP=20 nearer the intake ports? Let’s see; Rusty, Dave. . . who=20 else?

Al

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