Return-Path: Received: from [216.52.245.18] (HELO ispwestemail1.mdeinc.com) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP id 89622 for flyrotary@lancaironline.net; Tue, 25 May 2004 16:46:16 -0400 Received: from ispwest.com (unverified [216.52.245.25]) by ispwestemail1.mdeinc.com (Vircom SMTPRS 3.1.300.2) with ESMTP id for ; Tue, 25 May 2004 13:46:16 -0700 Message-ID: X-EM-APIVersion: 2, 0, 1, 0 X-Priority: 3 (Normal) From: "Bill Schertz" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Fuel Pump Design Date: Tue, 25 May 2004 13:46:15 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_84815C5ABAF209EF376268C8" ------=_NextPart_84815C5ABAF209EF376268C8 Content-type: text/html; charset=US-ASCII Content-Transfer-Encoding: quoted-printable =

Mark,

I have worried about this also, but based on your description, I have a=20= question=2E

It sounds like the line from the filters goes to the regulator, then back= to=20 the valve=2E Does the regulator sit after the fuel rail? Or does the AN-6 li= ne to=20 the injector branch off from the regulator and 'dead end' at the injectors?=20= There is a fellow running an E-racer with the latter system installed and it=20= works fine, but his pumps are below the level of the fuel tanks, at least 1 = foot=20 of head on the pumps=2E

I think the small bypass hole sounds more reliable than a solenoid switch= ,=20 etc=2E

Bill Schertz

----------------------------------

For the record, I have two of Tracy's efi pumps, with two efi filters, hooked in parallel=2E They are mounted low on the fire wall=2E=20 Upstream is a gascolator and an Andair 6-port selector valve=2E=20 Downstream of the pumps/filters is a map sensing pressure regulator=2E There is a -6AN going to the fuel rail, and a -4 return line back to the Andair valve/tank=2E

I was curious if anyone else has had this happen and what they did to resolve the issue=2E I have come up with two possible solutions=2E

1=2E Tee off the pump output and put an electric solenoid valve in the line and tee the outlet of the solenoid to the fuel return line, past the regulator=2E Push-button switch on panel would activate the solenoid=2E If needed, a second or two of activation should relieve the air-lock and allow the pumps to re-prime=2E

2=2E Install a bleed line around the pressure regulator with a small metering orifice (=2E020-=2E030") that would bleed off any air that might get trapped=2E (This appears to be the solution the Subaru group is focusing on)=2E This would be a full time bypass=2E This seems to be the simpler solution=2E

3=2E Install a low pressure, high volume fuel pump in one, or both, of the wing tanks=2E Procedure would be to always keep reserve fuel in this tank=2E

Any comments from seasoned flyers would be welcomed=2E

Mark S=2E

------=_NextPart_84815C5ABAF209EF376268C8 Content-type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable =09Mark, =09I have worried about this also, but based on your description, I have a q= uestion=2E =09It sounds like the line from the filters goes to the regulator, then back= to the valve=2E Does the regulator sit after the fuel rail? Or does the AN-6 line t= o the injector branch off from the regulator and 'dead end' at the injectors? Ther= e is a fellow running an E-racer with the latter system installed and it works fi= ne, but his pumps are below the level of the fuel tanks, at least 1 foot of head= on the pumps=2E =09I think the small bypass hole sounds more reliable than a solenoid switch= , etc=2E =09Bill Schertz =09---------------------------------- =09For the record, I have two of Tracy's efi pumps, with two efi filters, hooked in parallel=2E They are mounted low on the fire wall=2E Upstream is a gascolato= r and an Andair 6-port selector valve=2E Downstream of the pumps/filters is a map sen= sing pressure regulator=2E There is a -6AN going to the fuel rail, and a -4 return line back to the Andair valve/tank=2E I was curious if anyone else has had this happen and what they did to resolve the issue=2E I have come up with two possible solutions=2E=20 1=2E Tee off the pump output and put an electric solenoid valve in the line and tee the outlet of the solenoid to the fuel return line, past the regulator=2E Push-button switch on panel would activate the solenoid=2E If needed, a second or two of activation should relieve the air-lock and allow the pumps to re-prime=2E 2=2E Install a bleed line around the pressure regulator with a small metering orifice (=2E020-=2E030") that would bleed off any air that might get trapped=2E (This appears to be the solution the Subaru group is focusing on)=2E This would be a full time bypass=2E This seems to be the simpler solution=2E 3=2E Install a low pressure, high volume fuel pump in one, or both, of the wing tanks=2E Procedure would be to always keep reserve fuel in this tank=2E=20 Any comments from seasoned flyers would be welcomed=2E Mark S=2E =20 ------=_NextPart_84815C5ABAF209EF376268C8--