Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2b7) with ESMTP id 310501 for flyrotary@lancaironline.net; Sat, 10 Jul 2004 11:52:12 -0400 Received: from EDWARD (clt25-78-058.carolina.rr.com [24.25.78.58]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i6AFpcPg018215 for ; Sat, 10 Jul 2004 11:51:39 -0400 (EDT) Message-ID: <002501c46695$cbc852c0$2402a8c0@EDWARD> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Turbo Overspeed??? Date: Sat, 10 Jul 2004 11:51:42 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0022_01C46674.4484A640" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0022_01C46674.4484A640 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok, thanks for the information, John Yes, the 1/2 inch hole may have contributed to more mass flow which = would push you (in my opinion) closer to the high speed part of the = turbo curves at that operating condition. I just wish I knew how much = mass flow we could get through a 1/2 hole at say 7.5 psi boost. I am = certain that somebody out there would figure that out. I probably = could, but I don't want to have all the fun {: ) Of course, this is all just speculation - but, I think its at a = minimum pointing toward a possible cause. I certainly wouldn't give up = on the stock turbo - I think the modifications that Max has to offer = will certainly help considerably. I personally believe they will = eliminate this problem. Hopefully, we will find out soon. Ed Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC ----- Original Message -----=20 From: John Slade=20 To: Rotary motors in aircraft=20 Sent: Saturday, July 10, 2004 11:21 AM Subject: [FlyRotary] Re: Turbo Overspeed??? > Pressure ratio boost creep.=20 Ed, More fascinating reading. Thanks. You might also want consider the air bleed on my intercooler. I = thought I'd mentioned this, but your analysis makes it more relevant so = I'll mention it again. There is a 1/2 inch outlet on the intercooler = which vents to atmosphere. Before getting the BOV I tried blocking it, = and found that the boost "went off the scale", so I unblocked it again. = It left it unblocked when I got the BOV think this was a "safety" = measure. Perhaps it was with respect to the engine & detonation, but not = so, I think, with respect to overspeeding the turbo. By the way I was = at 11,500 doing 5200rpm when the turbine wheel let go.=20 Oh, and for anyone thinking that this turbo stuff is way too much = complexity and trouble, let me point out that the 13B with 9PSI of boost = at only 4000 rpm is a truely powerful beast and well worth the effort. = (especially now I have the injectors wired correctly and the mixture = right). Sitting at 11k ft its VERY nice to add a couple of inches of = map and see an instant 1000 fpm, and if I can get the rpm up a bit more = at sea level with the new turbo I'm going to need a G suit for take off. = :) Regards, John=20 JTD? (Johns Turbo Demise). Is this what fame feels like??? ------=_NextPart_000_0022_01C46674.4484A640 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Ok, thanks for the information, = John

Yes, the 1/2 inch hole may = have=20 contributed to more mass flow which would push you (in my opinion) = closer to the=20 high speed part of the turbo curves at that operating condition. I = just=20 wish I knew how much mass flow we could get through a 1/2 hole at say = 7.5 psi=20 boost. I am certain that somebody out there would figure that = out. I=20 probably could, but I don't want to have all the fun {: )

Of course, this is = all just=20 speculation - but, I think its at a minimum pointing toward a possible=20 cause. I certainly wouldn't give up on the stock turbo - I = think the=20 modifications that Max has to offer will certainly help = considerably. I=20 personally believe they will eliminate this problem. Hopefully, we = will=20 find out soon.

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC

----- Original Message -----
From:=20 John=20 Slade
To: Rotary motors in = aircraft

Sent: Saturday, July 10, 2004 = 11:21=20 AM

Subject: [FlyRotary] Re: Turbo=20 Overspeed???

> Pressure ratio boost = creep.

Ed,

More fascinating reading.=20 Thanks.

You might also want consider the air bleed on my = intercooler. I=20 thought I'd mentioned this, but your analysis makes it more relevant = so I'll=20 mention it again. There is a 1/2 inch outlet on the intercooler which = vents to=20 atmosphere. Before getting the BOV I tried blocking it, and found that = the=20 boost "went off the scale", so I unblocked it again. It left it = unblocked when=20 I got the BOV think this was a "safety" measure. Perhaps it was with = respect=20 to the engine & detonation, but not so, I think, with respect to=20 overspeeding the turbo. By the way I was at 11,500 doing 5200rpm = when=20 the turbine wheel let go.

Oh, and for anyone thinking that this turbo = stuff is=20 way too much complexity and trouble, let me point out that the 13B = with 9PSI=20 of boost at only 4000 rpm is a truely powerful beast and well worth = the=20 effort. (especially now I have the injectors wired correctly and the = mixture=20 right). Sitting at 11k ft its VERY nice to add a couple of = inches of map=20 and see an instant 1000 fpm, and if I can get the rpm up a bit more at = sea=20 level with the new turbo I'm going to need a G suit for take off.=20 :)

Regards,

John=20
JTD? (Johns Turbo Demise). Is this what fame feels=20 = like???
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