Return-Path: Received: from fed1mtao02.cox.net ([68.6.19.243] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2577944 for flyrotary@lancaironline.net; Sat, 13 Sep 2003 01:46:31 -0400 Received: from Leonards ([68.111.228.182]) by fed1mtao02.cox.net (InterMail vM.5.01.06.05 201-253-122-130-105-20030824) with ESMTP id <20030913054630.PZZW25496.fed1mtao02.cox.net@Leonards> for ; Sat, 13 Sep 2003 01:46:30 -0400 From: "David Leonard" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: turbo wastegate requirements Date: Fri, 12 Sep 2003 22:46:31 -0700 Message-ID: <000401c379ba$6279c010$b6e46f44@Leonards> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0005_01C3797F.B61AE810" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.3416 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_0005_01C3797F.B61AE810 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit There are two types of 'pop-off valves' - more accurately relief valves and blow by valves. Relief valves are simple spring loaded valves that relieve excess pressure in order to save the system/engine from over boost. This is what we need but they are sometimes hard to find. Blow by valves are very common as aftermarket additions in cars are commonly called "pop off valves." They use a MAP(downstream) reference and a spring. With the throttle open, the valve stays closed almost regardless of the MAP. When the throttle closes, the vacuum on the MAP reference opens the valve and bleeds the air on the upstream side of the throttle. This protects the turbo from over boost when the throttle is suddenly closed but does not protect the engine when the throttle is open. The primary purpose in street racing is to keep the turbo spooled up during shifting and to make a cool sound. Marv, if you have one of these do not connect the MAP reference, or better yet, get a true relief valve. David Leonard The Rotary Roster: http://members.aol.com/_ht_a/rotaryroster/index.html -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Russell Duffy Sent: Thursday, September 11, 2003 7:09 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: turbo wastegate requirements The popoff on the intake manifold is referenced to MAP and not boost, and set to blow off at my intended 34" MAP redline... this way the overboost protection is unaffected by ambient pressure. Hi Marvin, I'd love to know how you're doing this, since it's exactly what I need. I've never seen any sort of valve that's referenced to MAP. The only thing I can imagine is an electric valve that's electronically controlled. Thanks, Rusty (gotta get me one of those) ------=_NextPart_000_0005_01C3797F.B61AE810 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message

There are two types of ‘pop-off valves’ – more accurately = relief valves and blow by valves.

 

Relief valves are simple spring = loaded valves that relieve excess pressure in order to save the system/engine = from over boost. This is what we need but they are sometimes hard to = find.

 

Blow by valves are very common as = aftermarket additions in cars are commonly called “pop off = valves.”  They use a MAP(downstream) reference and a spring.  With the throttle = open, the valve stays closed almost regardless of the MAP.  When the throttle closes, the vacuum on the MAP reference opens the valve and bleeds the = air on the upstream side of the throttle.  This protects the turbo from = over boost when the throttle is suddenly closed but does not protect the = engine when the throttle is open.  The primary purpose in street racing is to = keep the turbo spooled up during shifting and to make a cool sound.  Marv, = if you have one of these do not connect the MAP reference, or better yet, get a = true relief valve.

 

David Leonard

The Rotary = Roster:

http://memb= ers.aol.com/_ht_a/rotaryroster/index.html

 

-----Original Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Russell Duffy
Sent: Thursday, September 11, 2003 7:09 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = turbo wastegate requirements

 

The popoff on the intake manifold is referenced to MAP and not
boost, and set to blow off at my intended 34" MAP redline... this = way the
overboost protection is unaffected by ambient pressure. 

        = <marv>

 

Hi Marvin,

 

I'd love to know how you're doing = this, since it's exactly what I need.  I've never seen any sort of valve = that's referenced to MAP.  The only thing I can imagine is an electric = valve that's electronically controlled.  

 

Thanks,

Rusty (gotta get me one of = those)

 

 

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