X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-gy0-f180.google.com ([209.85.160.180] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTPS id 5110364 for flyrotary@lancaironline.net; Thu, 01 Sep 2011 07:57:01 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.160.180; envelope-from=rwstracy@gmail.com Received: by gyc15 with SMTP id 15so2593645gyc.25 for ; Thu, 01 Sep 2011 04:56:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; bh=PQO5syOmWg2xEZolYa3c08bxXfXJOdHZEfm4OCKhcpY=; b=h9PBfTVEiy8H47cqPe/jrqaGH5zpusOVjKAC1XvMiE/pwneRMITnhisnIGdmnFMI4f 46yYw0gdfG7ifyj5zQrHWuHQEiyuP41SFJqUJ8A//xTUA+jKj/W5n+EDPa1ENpuDZc2i P6Fp1mwKmkGSGZDvR9kvUhtw7EOkVxwt2+gKo= Received: by 10.236.179.101 with SMTP id g65mr756961yhm.64.1314878184732; Thu, 01 Sep 2011 04:56:24 -0700 (PDT) Return-Path: Received: from [10.0.1.2] (99-197-145-127.cust.wildblue.net [99.197.145.127]) by mx.google.com with ESMTPS id j45sm696379yhe.78.2011.09.01.04.56.10 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 01 Sep 2011 04:56:22 -0700 (PDT) Subject: Re: [FlyRotary] Re: CG Products Intake Manifold References: From: Tracy Content-Type: multipart/alternative; boundary=Apple-Mail-74--583961932 X-Mailer: iPad Mail (8F191) In-Reply-To: Message-Id: <27639387-37B9-464F-9CC9-25571C84DF78@gmail.com> Date: Thu, 1 Sep 2011 07:55:54 -0400 To: Rotary motors in aircraft Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (iPad Mail 8F191) --Apple-Mail-74--583961932 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Hope I'm not thinking of the wrong incident and installation Bobby. I was g= oing on a picture of your pump installation someone else posted. Top notch w= orkmanship but it definitely had a pump inlet filter. Must have been someon= e else's or an early photo before final configuration. Tracy Sent from my iPad On Aug 31, 2011, at 5:19 PM, "Bobby J. Hughes" wrote: > Tracy, > =20 > I have no filters on the inlet side of the pumps. Early on I had one filte= r at the outlet of each tank but they were removed after a few flight hours.= They were the same GM style filters that may use on the high pressure side o= f our fuel systems. Never any indication of fuel flow problems but no pressu= re drop data was available from the manufacture. I was experiencing fuel pre= ssure not tracking manifold pressure on a one to one basis. It would go high= er under boost but sometimes not come down as expected. I removed the filter= s at the suggestion of Aeromotive tech support. I still have the condition a= nd need to try a different regulator. I have one large filter at the firewal= l and it always looks clean. I=E2=80=99m confident my power failure was not= fuel =E2=80=9Cfilter=E2=80=9D related and I don=E2=80=99t think it was vapo= r lock. But I=E2=80=99m also not 100% sure it was the Hushpower muffler. I= moved throttle several time through its entire range with no improvements. S= itting on the taxiway after landing the engine would not make power. A few m= inutes later when restarted it made full power. I did call Ed Klepis the day= after the FAA inspected the plane and suggested they check the muffler. No f= eedback so far. > =20 > Just for fun play the attached file in Google Earth. My poor piloting skil= l are evident as I let a stiff wind blow me off center line just after rotat= ion. However tracking the centerline on landing was not an issue even with t= he tail wind. As Ed says =E2=80=9Cemergency=E2=80=99s have a way of focusing= your mind.=E2=80=9D > =20 > Bobby > =20 > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Be= half Of Tracy > Sent: Wednesday, August 31, 2011 12:29 PM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: CG Products Intake Manifold > =20 > Have to agree with Al W. on this one. I have never seen smoking gun evid= ence that vapor lock occurs in the fuel rails. I have seen MANY smoking gu= ns pointing at problems in the pump inlet circuit. =20 > =20 > That pump inlet filter on Bobby Hugh's installation raised a big red flag f= or me as a possible cause of his power failure. It looks like the identical= filter that caused the same problem on my 20B. Ed Klepis talked with me a= bout the problem but unfortunately Bobby is not communicating about it AFAIK= . =20 > =20 > BTW, Here is one piece of advice when you experience a power loss at hig= h throttle. All engine systems are under maximum stress at full power and i= t is often the case that if you ask a bit less of them, they might work bett= er. I understand the urge to firewall the throttle when power sags at take= off but TRY reducing throttle momentarily to see if you get better engine pe= rformance. This has saved me from at least three aircraft accidents. When= that clogged inlet filter caused a power sag in the RV-8, backing off on th= e throttle lowered the fuel demand of the engine and the fuel pressure recov= ered enough to let the engine run normally at reduced throttle. Same thing= applies to other situations. When my Rotax powered Twinstar started loosi= ng power on climb out I reduced throttle and the engine recovered. Piston s= eizure was the problem but reducing throttle let the piston cool a bit and t= otal seizure was avoided. I replaced rings & scuffed pistons after nursing= it 80 miles to home. > =20 > Tracy >=20 >=20 > Sent from my iPad >=20 > On Aug 31, 2011, at 9:50 AM, "Al Wick" wrote: >=20 >> > =20 >> So you are saying every car built since 1990 has this "vapor lock" proble= m? We would see thousands of cars unable to start at every desert truck stop= . This concern for fuel rail is a myth. >> =20 >> Vapor lock is not a myth. It occurs at the fuel pump inlet. Very importan= t to minimize pressure drop there. You can actually measure how far your des= ign is from vapor lock. You don't have to guess. >> =20 >> The bleed helps if you totally blew the plumbing from tank to fuel pump. B= ut much better to fix that plumbing error. =20 >> =20 >> =20 >> -al wick >> ----- Original Message ----- >> From: Dave >> To: Rotary motors in aircraft >> Sent: Tuesday, August 30, 2011 9:14 PM >> Subject: [FlyRotary] Re: CG Products Intake Manifold >> =20 >> HOWEVER..... if there is not a method to bleed down the rail the risk of v= apor lock exists, as the rail heats, the fuel boils, and the vapor gets trap= ped in the line. >>=20 >> If you DO put the regulator upstream of the rail, its imperative to be ab= le to be able to flow fuel past the injectors and to a return line to avoid a= ny possibility of vapor lock. The easiest way is simply to put the regulator= downstream of the rail and injectors, but again.. this arrangement is more a= bout preventing vapor lock, not ensuring adequate pressure.=20 >>=20 >> Chris and I were forced into the upstream approach by the Mistral fuel ra= il configuration, and I didn't want to mess with drilling out the pinhole an= d then running a regulator downstream - Mistral was hard enough to get the i= ntake from, and we didn't expect getting a replacement part if we had an OOO= PS would have been easy. As others have now found out, Mistral isn't selling= parts.=20 >>=20 >> So... anyways.. just wanted to clarify previous post. 1) can regulate pr= essure anywhere in the fuel circuit between pumps and injectors. 2) Must pro= vide for mechanism to flow fuel past injectors to prevent vapor lock. >>=20 >> Dave >>=20 >> On 8/30/2011 11:06 PM, Dave wrote: >> No... at the flows and pressures we are using (and barring any major obst= ructions between the regulator and the injectors), the regulator can be anyw= here in the circuit and adequately regulate the pressure. >>=20 >> On Chris Barber's install, I purchased the Mistral intake for use on his e= ngine. The fuel rail was a dead end tube with a pinhole on the end. Presumab= ly the pinhole was to prevent vapor lock in the fuel rail. The regulator HAD= to be upstream of the injectors when using the intake. We had stable fuel p= ressures and no problems getting fuel to the engine.=20 >>=20 >> We had return lines from the pinhole end of the rail, as well as from the= pressure regulator, that fed back to the sump tank. Since there were not ch= eck valves running from the wings to the sump, there was no chance of pressu= rizing the sump.=20 >>=20 >> Dave >>=20 >> On 8/30/2011 10:30 PM, CozyGirrrl@aol.com wrote: >> Ed, I must have mispoke to give this impression, I thought the pressure r= eg HAD TO be last in line to maintain pressure in the fuel rail? >> =20 >> =20 >> Chrissi & Randi >> www.CozyGirrrl.com >> CG Products, Custom Aircraft Hardware >> Chairwomen, Sun-N-Fun Engine Workshop >> =20 >> In a message dated 8/30/2011 10:13:53 P.M. Central Daylight Time, eanders= on@carolina.rr.com writes: >> If the pressure regulator is place before the injectors then there is l= ess fresh fuel flowing through the rails.=20 >> =20 >> =20 >=20 > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List= .html --Apple-Mail-74--583961932 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
Hope I'm not thinking of the wrong inci= dent and installation Bobby.   I was going on a picture of your pump in= stallation someone else posted.  Top notch workmanship but it definitel= y had a pump inlet filter.  Must have been someone else's or an early p= hoto before final configuration.

Tracy

Sent f= rom my iPad

On Aug 31, 2011, at 5:19 PM, "Bobby J. Hughes" <= ;bhughes@qnsi.net> wrote:

=

Tracy,

 

I have no filters on the inlet side of t= he pumps. Early on I had one filter at the outlet of each tank but they were removed after a few flight hours. They were the same GM style filters that m= ay use on the high pressure side of our fuel systems. Never any indication of f= uel flow problems but no pressure drop data was available from the manufacture. I= was experiencing fuel pressure not tracking manifold pressure on a one to on= e basis. It would go higher under boost but sometimes not come down as expecte= d. I removed the filters at the suggestion of Aeromotive tech support. I still ha= ve the condition and need to try a different regulator. I have one large filter= at the firewall and it always looks clean.  I=E2=80=99m confident my power= failure was not fuel =E2=80=9Cfilter=E2=80=9D related and I don=E2=80=99t think it was vapor= lock.   But I=E2=80=99m also not 100% sure it was the Hushpower muffler. I moved throttle several time throug= h its entire range with no improvements. Sitting on the taxiway after landing the engine would not make power. A few minutes later when restarted it made full= power. I did call Ed Klepis the day after the FAA inspected the plane and su= ggested they check the muffler. No feedback so far.

 

Just for fun play the attached file in Google Earth. My poor piloting skill are evident as I let a stiff wind blow m= e off center line just after rotation. However tracking the centerline on land= ing was not an issue even with the tail wind. As Ed says =E2=80=9Cemergency=E2=80= =99s have a way of focusing your mind.=E2=80=9D

 

Bobby

 

From: Rotary motors in aircraft [mailto:fly= rotary@lancaironline.net] On Behalf Of Tracy
Sent: Wednesday, August 31, 2= 011 12:29 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: CG Products Intake Manifold

 

Have to agree with Al W. on this one.   I have never seen smoki= ng gun evidence that vapor lock occurs in the fuel rails.   I have seen MA= NY smoking guns pointing at problems in the pump inlet circuit.  

 

That pump inlet filter on Bobby Hugh's installation raised a big red= flag for me as a possible cause of his power failure.  It looks like th= e identical filter that caused the same problem on my 20B.   Ed Klepis talked with me about the problem but unfortunately Bobby is not communicatin= g about it AFAIK.  

 

BTW,   Here is one piece of advice when you experience a power loss at high throttle.  All engine systems are under maximum stress at full power and it is often the case that if you ask a bit less of them, they= might work better.   I understand the urge to firewall the throttle whe= n power sags at takeoff but TRY reducing throttle momentarily to see if you ge= t better engine performance.  This has saved me from at least three aircr= aft accidents.   When that clogged inlet filter caused a power sag in the RV-8, backing off on the throttle lowered the fuel demand of the engine and t= he fuel pressure recovered enough to let the engine run normally at reduced throttle.   Same thing applies to other situations.   When my Rota= x powered Twinstar started loosing power on climb out I reduced throttle and t= he engine recovered.   Piston seizure was the problem but reducing throttl= e let the piston cool a bit and total seizure was avoided.   I replaced rings & scuffed pistons after nursing it 80 miles to home.

 

Tracy



Sent from my iPad


On Aug 31, 2011, at 9:50 AM, "Al Wick" <alwick@juno.com> wrote:=

<if there is not a method to bleed down the rail the risk of vapo= r lock exists

 

So you are saying every car built since 1990 has this "vapor lock" problem? We would see thousands of cars unable to start at every desert truck stop. This concern for fuel rail is a myth. <= /font>

 

Vapor lock is not a myth. It occurs at the fuel pump inlet. Very important to minimize pressure drop there. You can actually measure how far your design is from vapor lock. You don't have to guess.

 

The bleed helps if you totally blew the plumbing from tank to f= uel pump. But much better to fix that plumbing error.  

 

 

-al wick

----- Original Message -----

From: Dave

Sent: Tuesday, A= ugust 30, 2011 9:14 PM

Subject: [FlyRo= tary] Re: CG Products Intake Manifold

 

HOWEVER..... if there is not a method to bleed down the rail the ris= k of vapor lock exists, as the rail heats, the fuel boils, and the vapor gets trapped in the line.

If you DO put the regulator upstream of the rail, its imperative to be able t= o be able to flow fuel past the injectors and to a return line to avoid any possibility of vapor lock. The easiest way is simply to put the regulator downstream of the rail and injectors, but again.. this arrangement is more about preventing vapor lock, not ensuring adequate pressure.

Chris and I were forced into the upstream approach by the Mistral fuel rail configuration, and I didn't want to mess with drilling out the pinhole and t= hen running a regulator downstream - Mistral was hard enough to get the intake from, and we didn't expect getting a replacement part if we had an OOOPS wou= ld have been easy. As others have now found out, Mistral isn't selling parts. <= br>
So... anyways.. just wanted to clarify previous post.  1) can regulate pressure anywhere in the fuel circuit between pumps and injectors. 2) Must provide for mechanism to flow fuel past injectors to prevent vapor lock.
=
Dave

On 8/30/2011 11:06 PM, Dave wrote:

No... at the flows and pressures we are using (and barring any major= obstructions between the regulator and the injectors), the regulator can be anywhere in the circuit and adequately regulate the pressure.

On Chris Barber's install, I purchased the Mistral intake for use on his engine. The fuel rail was a dead end tube with a pinhole on the end. Presuma= bly the pinhole was to prevent vapor lock in the fuel rail. The regulator HAD to= be upstream of the injectors when using the intake. We had stable fuel pressure= s and no problems getting fuel to the engine.

We had return lines from the pinhole end of the rail, as well as from the pressure regulator, that fed back to the sump tank. Since there were not che= ck valves running from the wings to the sump, there was no chance of pressurizi= ng the sump.

Dave

On 8/30/2011 10:30 PM, CozyGirrrl@aol.com wrote:

Ed, I must have mispoke to give this impression, I thought the pressure reg HAD TO be last in line t= o maintain pressure in the fuel rail?

 

 

Chrissi & Randi
www.CozyGi= rrrl.com
CG Products, Custom Aircraft Hardware
Chairwomen, Sun-N-Fun Engine Workshop

 

In a message dated 8/30/2011 10:13:53 P.M. Central Daylight Time, eanderson@carolina.rr.com writes:

  If the pressure regulator is pl= ace before the injectors then there is less fresh fuel flowing through the rails. 

 

 

<bjh.kmz>
<= /html>= --Apple-Mail-74--583961932--