Return-Path: Received: from corpprd-pxy2.canfor.ca ([198.162.160.3] verified) by logan.com (CommuniGate Pro SMTP 4.2b6) with ESMTP id 300997 for flyrotary@lancaironline.net; Fri, 09 Jul 2004 15:55:57 -0400 Received: from canformail1.canfor.ca (canformail1.canfor.ca [199.60.193.29]) by corpprd-pxy2.canfor.ca (Build 103 8.9.3p2/NT-8.9.3) with ESMTP id MAA03378 for ; Fri, 09 Jul 2004 12:55:28 -0700 X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message Subject: RE: [FlyRotary] Re: Turbo post mortem Date: Fri, 9 Jul 2004 12:55:18 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C465EE.A90ADDE0" Message-ID: <1F17B59A61D4194095359264D24D22A2708CA0@mailman.canfor.ca> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: Turbo post mortem Thread-Index: AcRltjvZxFjMMOk1T42htGia09Z1iwZdXIQg From: "Bartrim, Todd" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C465EE.A90ADDE0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable > Not to be too critical, but isn't Todd the only one (so far) to damage = his engine due to overboost induced detonation? Maybe it's just me, but = I'd call that a turbo problem :-) =20 >=20 Gee Rusty, it sounds like a case of turbo envy :-). But seriously, as = Ed has said it was mostly a case of inexperienced pilot error. Another = factor that I'm beginning to believe significantly contributed to the = problem was improper tuning. With the EM2's ability to tune the MAP = table, I had made some large changes (including a slightly advanced = timing to improve idle) For some reason Tracy's default programming = didn't work very well before I rebuilt my engine and required large = tuning changes, however after I reinstalled the engine, recognizing that = my tuning was inadequate, I reset it to factory default and surprisingly = this time it ran very well with no change at all. I have leaned slightly = at idle, but otherwise have made no changes as of yet. I've been making = note of a few spots that will require a little tuning, but in the hi MAP = table all is pretty darn good. The low MAP table is where I need to do a = little more tuning to get it a little smoother on descent. But back to the original question regarding turbo reliability. I don't = have a BOV or POV or any other bleeds in the system after the compressor = as I don't feel that it is efficient to make the engine do work to = compress the air only to bleed it off again. This also puts unnecessary = stress on the turbo components. Bypassing the exhaust turbine through a = wastegate is the best way to control boost IMHO. My porting of the = wastegate and recently drilling through the center scroll seems to have = made a big difference as I've not seen my boost levels ever exceed 7 psi = in my now 18.2 flight hours (except when I opened up the wastegate = actuator bleed valve on the sensing line to give me 10psi at altitude). = Now if I could get a spare series 4 turbine housing, I'd bring it in = here to the mill and attempt mounting it on a lathe to increase the A/r, = but I suspect that this procedure would be far more critical than the = wastegate mods I've performed. S. Todd Bartrim (hates paying for work that I think I can do myself) Turbo 13B RX-9endurance C-FSTB http://www3.telus.net/haywire/RV-9/C-FSTB.htm "Imagination is more important than knowledge" -Albert Einstein ------_=_NextPart_001_01C465EE.A90ADDE0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable RE: [FlyRotary] Re: Turbo post mortem

Not to be = too critical, but isn't Todd the only one (so far) to damage his engine = due to overboost induced detonation?  Maybe it's just me, but I'd = call that a turbo problem :-) 

        Gee Rusty, it sounds like a case of turbo envy = :-). But seriously, as Ed has said it was mostly a case of inexperienced = pilot error. Another factor that I'm beginning to believe significantly = contributed to the problem was improper tuning. With the EM2's ability = to tune the MAP table, I had made some large changes (including a = slightly advanced timing to improve idle) For some reason Tracy's = default programming didn't work very well before I rebuilt my engine and = required large tuning changes, however after I reinstalled the engine, = recognizing that my tuning was inadequate, I reset it to factory default = and surprisingly this time it ran very well with no change at all. I = have leaned slightly at idle, but otherwise have made no changes as of = yet. I've been making note of a few spots that will require a little = tuning, but in the hi MAP table all is pretty darn good. The low MAP = table is where I need to do a little more tuning to get it a little = smoother on descent.

        But back to the original question regarding = turbo reliability. I don't have a BOV or POV or any other bleeds in the = system after the compressor as I don't feel that it is efficient to make = the engine do work to compress the air only to bleed it off again. This = also puts unnecessary stress on the turbo components. Bypassing the = exhaust turbine through a wastegate is the best way to control boost = IMHO. My porting of the wastegate and recently drilling through the = center scroll seems to have made a big difference as I've not seen my = boost levels ever exceed 7 psi in my now 18.2 flight hours (except when = I opened up the wastegate actuator bleed valve on the sensing line to = give me 10psi at altitude). Now if I could get a spare series 4 turbine = housing, I'd bring it in here to the mill and attempt mounting it on a = lathe to increase the A/r, but I suspect that this procedure would be = far more critical than the wastegate mods I've = performed.

S. Todd Bartrim = (hates paying for work that I think I can do = myself)
Turbo = 13B
RX-9endurance
C-FSTB
http://www3.telus.= net/haywire/RV-9/C-FSTB.htm

        "Imagination is more important than = knowledge"
        =         =         =         =         -Albert Einstein


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