Return-Path: Received: from wb2-a.mail.utexas.edu ([128.83.126.136] verified) by logan.com (CommuniGate Pro SMTP 4.2b6) with ESMTP-TLS id 220332 for flyrotary@lancaironline.net; Mon, 21 Jun 2004 09:01:48 -0400 Received: (qmail 76996 invoked from network); 21 Jun 2004 13:01:16 -0000 Received: from dhcp-191-101.per.utexas.edu (HELO benefits3.mail.utexas.edu) (146.6.191.101) by wb2.mail.utexas.edu with RC4-SHA encrypted SMTP; 21 Jun 2004 13:01:16 -0000 Message-Id: <5.1.1.5.2.20040621074403.0258f670@localhost> X-Sender: msteitle@mail.utexas.edu@localhost X-Mailer: QUALCOMM Windows Eudora Version 5.1.1 Date: Mon, 21 Jun 2004 07:59:35 -0500 To: "Rotary motors in aircraft" From: Mark Steitle Subject: Re: [FlyRotary] Re: [FlyRotary ] fuel delivery In-Reply-To: Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="=====================_315173656==.ALT" --=====================_315173656==.ALT Content-Type: text/plain; charset="us-ascii"; format=flowed Barny, No, unfortunately I won't be going to OSH this year, but I am making plans for Tracy's rotorhead gathering in October. Your fuel system sounds similar to mine, except I have a 6-port Andair valve instead of a "T". The big difference though is the wing location. With a high wing you have better flow (head) into the pumps. At the very least, I will be shielding my pumps and feeding cool outside air to them and the gascolator. One condition I would strongly recommend you test for is for an air-lock that can form between the pump outlet and pressure regulator. I have experienced this following fuel supply exhaustion. The only way to get the system going again was to crack open the line feeding the fuel rail, releasing the trapped air, until the pump could re-prime. Although I don't plan on running either tank dry on a regular basis, I definitely want the system to be able to recover if/when it does happen. The solution was pretty simple. I installed a .025" bleed orifice which bypasses the pressure regulator and tees back into the fuel return line. It provides enough bypass to get things going again, but not so much as to mess up the fuel rail pressures. Mark S. At 09:16 PM 6/17/2004 -0500, you wrote: >Mark S., > >I know that your 20b install is different that mine, a low wing tricycle >vs high wing taildragger. I'm copying a successful fuel system that is >being used on a v-6 and one v-8 installs. Fuel lines under the cowl are >on the cool side of the engine. So is the TB. Two 3/8 lines from the tank >to a T with a 1/2 inch feed going to the gascolator. Then 1/2 in to the >two fuel pumps/filters in parallel. One 3/8 line from the filters going to >a bulkhead fitting on the firewall than to the feed rail. The return line >goes back on a 3/8 line to a T and back to the tanks. Plan A is to have >both wings feeding, and both wings able to take the return fuel where ever >it wants to go to. Time will tell how much and where it feeds and returns >to. I can however pick which tank to go for the return and feed. The >return ports are about an inch above the pickups (2) on the wing. >Gascolator, fuel pumps, and filters are going under the floor of the >cockpit. Should there be a gas leak in the cabin, I would rather have it >there than have it under the cowl with the turbo. There will be a vent >for the pumps to stay cool. Will be using Cub style of site gauges for >fuel levels. > > You and Bob going to OSH this year? > >Murphy note. Many builders seal the metal wet wing that has >NINE &%^#$#%& stringers going thru it. There are alot that test great and >start to leak on taxi tests and on the first 40 hours. Mine tested >great. I hope they leak so I can open them out to 120 gallon tanks....... > >My wife wants a EC-2 for a 20bt for her birthday........... Hmmmm > >Barny >MGDQ 20bt > --=====================_315173656==.ALT Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Barny,
No, unfortunately I won't be going to OSH this year, but I am making plans for Tracy's rotorhead gathering in October. 

Your fuel system sounds similar to mine, except I have a 6-port Andair valve instead of a "T".  The big difference though is the wing location.  With a high wing you have better flow (head) into the pumps.  At the very least, I will be shielding my pumps and feeding cool outside air to them and the gascolator. 

One condition I would strongly recommend you test for is for an air-lock that can form between the pump outlet and pressure regulator.  I have experienced this following fuel supply exhaustion.  The only way to get the system going again was to crack open the line feeding the fuel rail, releasing the trapped air, until the pump could re-prime.  Although I don't plan on running either tank dry on a regular basis, I definitely want the system to be able to recover if/when it does happen.  The solution was pretty simple.  I installed a .025" bleed orifice which bypasses the pressure regulator and tees back into the fuel return line.  It provides enough bypass to get things going again, but not so much as to mess up the fuel rail pressures.

Mark S.

 

   At 09:16 PM 6/17/2004 -0500, you wrote:
Mark S.,
 
I know that your 20b install is different that mine, a low wing tricycle vs high wing taildragger. I'm copying a successful fuel system that is being used on a v-6 and one v-8 installs.  Fuel lines under the cowl are on the cool side of the engine. So is the TB. Two 3/8 lines from the tank to a T with a 1/2 inch feed going to the gascolator. Then 1/2 in to the two fuel pumps/filters in parallel. One 3/8 line from the filters going to a  bulkhead fitting on the firewall than to the feed rail. The return line goes back on a 3/8 line to a T and back to the tanks.  Plan A is to have both wings feeding, and both wings able to take the return fuel where ever it wants to go to. Time will tell how much and where it feeds and returns to.    I can however pick which tank to go for the return and feed. The return ports are about an inch above the pickups (2) on the wing. Gascolator, fuel pumps, and filters are going under the floor of the cockpit.  Should there be a gas leak in the cabin, I would rather have it there than have it under the cowl with the turbo.  There will be a vent for the pumps to stay cool. Will be using Cub style of site gauges for fuel levels.
 
 You and Bob going to OSH this year?
 
Murphy note.  Many builders seal the meta= l wet wing that has NINE  &%^#$#%& stringers going thru it. There are alot that test great and start to leak on taxi tests and on the first 40 hours.  Mine tested great.  I hope they leak so I can open them out to 120 gallon tanks.......
 
My wife wants a EC-2 for a 20bt for her birthday........... Hmmmm
 
Barny
MGDQ 20bt
 
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