Return-Path: Received: from relay03.roc.ny.frontiernet.net ([66.133.131.36] verified) by logan.com (CommuniGate Pro SMTP 4.1.6) with ESMTP id 2701694 for flyrotary@lancaironline.net; Wed, 29 Oct 2003 12:41:45 -0500 Received: (qmail 20877 invoked from network); 29 Oct 2003 17:41:14 -0000 Received: from unknown (HELO frontiernet.net) ([170.215.97.8]) (envelope-sender ) by relay03.roc.ny.frontiernet.net (FrontierMTA 2.3.6) with SMTP for ; 29 Oct 2003 17:41:14 -0000 Message-ID: <3F9FFBE3.CFA066B3@frontiernet.net> Date: Wed, 29 Oct 2003 11:41:55 -0600 From: Jim Sower X-Mailer: Mozilla 4.77 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Intake manifold References: Content-Type: multipart/alternative; boundary="------------090BA96E986FEC409B48E7AA" --------------090BA96E986FEC409B48E7AA Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit As long as we're talking relative runner lengths of primary and secondary runners, I started wondering about having two runners per rotor. I've never been clear about why there are two, and wondered if perhaps it had something to do with running up and down through the gears (which airplanes do not do). Could someone provide me with a quick and dirty explanation of why we have primary and secondary runners, and why we need them both for steady state operation? Seems as if DIE would also be greatly simplified if there were only one runner per rotor. I missed that class waaaaay back when .... Jim S. Finn Lassen wrote: > Well, after attending Ed's presentation I see there is a > significant difference (inches) between the required runner > length for the primary vs the secondary ports. That is for the > 1988 NA stock (non-street-ported). So combining primaries with > secondaries close to the ports may sacifice some of the DIE > effect. How much I don't know. It will be good to get some > real world data in this configuration. Obviously it will fly > as-is. I'm just talking about egging the last few HPs out of > an NA installation at the optimized RPM and inlet temp. > > Finn > > sqpilot@earthlink wrote: > >> Hi, fellow rotary enthusiasts....just a quick update on the >> progress of my new intake system. I purchased the >> Austrailian 90 degree intake manifold from Mazdatrix. I cut >> the top off, and brought it to my machinist friend, who took >> a boring bar on a Bridgeport, and plunge-cut two nice >> receptacles for my 90 degree aluminum bends. I purchased >> two 4"x12" 90 degree bends from Burns stainless, as well as >> two 45 degree bends. I had them expand the end of the >> 4"x12" 90 degree tubing, so that the 45 would slide right >> into it. It fit nicely. The machinist is now making an >> aluminum mounting plate with two holes in it that the two 45 >> degree tubes will slide into, and it will be welded on the >> outside. This mounting plate has four 5/16-18 threaded studs >> screwed into it, to which my throttlebody will mount. He put >> it on his computer, so he can duplicate this piece easily if >> needed. It is a very simple system, with only one 90 degree >> bend to take the tubes over the top of the engine, and then >> one 45 degree bend to position the throttlebody on the cold >> side of the engine, similar to Paul Lamar's setup, with the >> exception that the intake manifold goes from 4 into two >> right in the casting, so only two intake runners are >> needed. Since the longer tube has been expanded, I can >> slide the shorter 45 degree tubing in or out to fit just >> where I need it, or for tuning the intake system. I should >> have everything back from the machininst in a couple of >> days, at which point I will post some pictures. I hope I >> described this sufficiently enough to confuse everyone. The >> pictures will clarify everything much better than my >> description, I'm sure. Sure am sorry I was unable to >> attend Shady Bend. Unfortunately, I had to work to pay for >> my third manifold. Paul, the manifold collector, Conner. > -- Jim Sower Crossville, TN; Chapter 5 Long-EZ N83RT, Velocity N4095T --------------090BA96E986FEC409B48E7AA Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit As long as we're talking relative runner lengths of primary and secondary runners, I started wondering about having two runners per rotor.  I've never been clear about why there are two, and wondered if perhaps it had something to do with running up and down through the gears (which airplanes do not do).

Could someone provide me with a quick and dirty explanation of why we have primary and secondary runners, and why we need them both for steady state operation?  Seems as if DIE would also be greatly simplified if there were only one runner per rotor.

I missed that class waaaaay back when .... Jim S.

Finn Lassen wrote:

Well, after attending Ed's presentation I see there is a significant difference (inches) between the required runner length for the primary vs the secondary ports. That is for the 1988 NA stock (non-street-ported). So combining primaries with secondaries close to the ports may sacifice some of the DIE effect. How much I don't know. It will be good to get some real world data in this configuration. Obviously it will fly as-is. I'm just talking about egging the last few HPs out of an NA installation at the optimized RPM and inlet temp.

Finn

sqpilot@earthlink wrote:

Hi, fellow rotary enthusiasts....just a quick update on the progress of my new intake system.  I purchased the Austrailian 90 degree intake manifold from Mazdatrix.  I cut the top off, and brought it to my machinist friend, who took a boring bar on a Bridgeport, and plunge-cut two nice receptacles for my 90 degree aluminum bends.  I purchased two 4"x12" 90 degree bends from Burns stainless, as well as two 45 degree bends.  I had them expand the end of the 4"x12" 90 degree tubing, so that the 45 would slide right into it. It fit nicely. The machinist is now making an aluminum mounting plate with two holes in it that the two 45 degree tubes will slide into, and it will be welded on the outside. This mounting plate has four 5/16-18 threaded studs screwed into it, to which my throttlebody will mount. He put it on his computer, so he can duplicate this piece easily if needed. It is a very simple system, with only one 90 degree bend to take the tubes over the top of the engine, and then one 45 degree bend to position the throttlebody on the cold side of the engine, similar to Paul Lamar's setup, with the exception that the intake manifold goes from 4 into two right in the casting, so only two intake runners are needed.  Since the longer tube has been expanded, I can slide the shorter 45 degree tubing in or out to fit just where I need it, or for tuning the intake system. I should have everything back from the machininst in a couple of days, at which point I will post some pictures. I hope I described this sufficiently enough to confuse everyone. The pictures will clarify everything much better than my description, I'm sure.       Sure am sorry I was unable to attend Shady Bend. Unfortunately, I had to work to pay for my third manifold.  Paul, the manifold collector, Conner.

--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T
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