REFLECTOR: Franklin Fuel Pump Issues

[Scott Derrick]

Your instruments will run fine and last longer at 4"-4.5".

Most systems are set way to high, which the AI and DG manufacturers love.

Scott

Jay Yu wrote:
> I was hoping to fly today. The gusty wind pushed me back. But I did engine
> runup and got the lower GREEN vacuum (~4.5" HG) at 2200 RPM. This is
> substantially better than 3" at 1800 RPM. All I did was to tighten
> everything and a few more engine runs.
> 
> Thanks all for your inputs.
> 
> Jay Yu
> 
> -----Original Message-----
> From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
> Behalf Of mike deeter
> Sent: Thursday, May 01, 2003 10:26 AM
> To: reflector@tvbf.org
> Subject: RE: REFLECTOR: Franklin Fuel Pump Issues
> 
> 
> Jay et al:
> 
> I just got back on the net after some travel
> (business, darn it, not Velocity).
> 
> My update on my vacuum.  I gradually adjusted my
> regulator to get 'middle of the green' on my gauge
> anytime I'm flying, certainly 1800 and above.  Now, my
> only issue is that it isn't easy or convenient to
> reliably set the DG on the ground prior to takeoff
> into IFR conditions.  I guess one could do a runup
> sitting on the runway just prior to the takeoff run.
> That'd probably get it done.
> 
> Otherwise, I'm satisfied I'm getting good vacuum
> during all flight ops.
> 
> Mike Deeter
> 
> 
> --- Jay Yu <jayyu@arczip.com> wrote:
> 
>>Hi Wayne,
>>
>>Thanks for the input. Based on the Franklin manual,
>>the accessary drive pad
>>on which I installed the vacuum pump has a drive
>>ratio of 0.847 which is
>>certainly less than 2 1/2. I wonder what vacuum
>>other builders with the same
>>configuration are getting.
>>
>>Thanks,
>>
>>Jay
>>
>>-----Original Message-----
>>From: reflector-admin@tvbf.org
>>[mailto:reflector-admin@tvbf.org]On
>>Behalf Of Wayne Owens
>>Sent: Sunday, April 27, 2003 9:59 PM
>>To: reflector@tvbf.org
>>Subject: Re: REFLECTOR: Franklin Fuel Pump Issues
>>
>>
>>Seems like the Airborne customer service folks told
>>me that pump RPM should
>>be 2 1/2 x crank rpm. Verify that. Can you crank
>>your prop over by hand and
>>count pump revolutions to determine what ratio you
>>are driving it at?
>>Wayne
>>----- Original Message -----
>>From: "Jay Yu" <jayyu@arczip.com>
>>To: <reflector@tvbf.org>; "mike deeter"
>><iguanamagic@yahoo.com>
>>Sent: Sunday, April 27, 2003 10:42 PM
>>Subject: RE: REFLECTOR: Franklin Fuel Pump Issues
>>
>>
>>
>>>Hi Mike and All Franklin Drivers,
>>>
>>>I know that I am late in the game on this. I just
>>
>>installed my new fuel
>>pump
>>
>>>that's working well. But, like Mike's original
>>
>>configuration, my SigmaTek
>>
>>>vacuum pump used to be on fuel pump drive and now
>>
>>has been moved to rear
>>
>>>pilot side. When I started the engine, I didn't
>>
>>get any vacuum at idle
>>
>>>speed. I only got about 3" HG when the engine was
>>
>>running 1800RPM. The
>>GREEN
>>
>>>arc is about 4.5" to 5.5" HG. How much vacuum can
>>
>>you get and at what RPM
>>
>>>(Mike?) What's the lowest vacuum we need for safe
>>
>>flight?
>>
>>>My vacuum pump did have about 80 hours in original
>>
>>configuration. In that
>>
>>>configuration, the vacuum was in GREEN easily (may
>>
>>be a little over 1000
>>
>>>RPM). With this new installation, I adjusted the
>>
>>vacuum regulator (both
>>ways
>>
>>>to extreme) but still cann't get more than 3" at
>>
>>about 1800 RPM.
>>
>>>Any and all hints will be greatly appreciated.
>>>
>>>Jay Yu
>>>N86YU
>>>Velocity RGE
>>>Franklin/MT
>>>
>>>
>>>
>>>-----Original Message-----
>>>From: owner-reflector@dax.awpi.com
>>>[mailto:owner-reflector@dax.awpi.com]On Behalf Of
>>
>>mike deeter
>>
>>>Sent: Friday, November 01, 2002 12:17 PM
>>>To: reflector@tvbf.org
>>>Subject: Re: REFLECTOR: Franklin Fuel Pump Issues
>>>
>>>
>>>Franklin drivers:
>>>
>>>OK , so now I'm answering my own emails.
>>>
>>>I just got off the phone w/ my engine builder,
>>
>>Pete
>>
>>>Askeland at Franklin Aircraft Engines, Inc. (FAEI)
>>
>>in
>>
>>>Colorado.
>>>
>>>Referring to the problems I've outlined in my
>>
>>email
>>
>>>below.  If you have a bidirectional vacuum pump
>>
>>you
>>
>>>will have no problem; just switch the input and
>>
>>output
>>
>>>lines.
>>>
>>>If you don't have a bidirectional pump you will
>>>obviously have to get a new vacuum pump.
>>>
>>>As for the speed of the accessory pad:  FAEI has
>>
>>the
>>
>>>STC for Cessnas w/ Franklins and they run their
>>
>>vacuum
>>
>>>pumps off the accessory pad in question, i.e. no
>>>problem running vacuum off the pad on the pilot
>>
>>side
>>
>>>near the prop.
>>>
>>>Sorry to get us all excited.
>>>
>>>Mike
>>>
>>>--- mike deeter <iguanamagic@yahoo.com> wrote:
>>>
>>>>Franklin drivers:
>>>>
>>>>Well, I got my fuel pump installed and fuel
>>>
>>lines
>>
>>>>redone.  I only needed to hoist the engine for
>>>>taking
>>>>the old one off.  I was able to reinstall the
>>>
>>new
>>
>>>>one
>>>>w/ the engine bolted tightly to the firewall.
>>>>
>>>>I installed the vacuum pump on the pilot side
>>>
>>accy
>>
>>>>pad
>>>>near the prop.  Unfortunately, this may not work
>>>
>>as
>>
>>>>well as PZL intended.  Larry Coen pointed out
>>>
>>the
>>
>>>>accy
>>>>pads near the prop turn 0.847 times crank CW
>>>
>>while
>>
>>>>the
>>>>accy pad on the rear of the engine (fuel pump
>>>
>>mount)
>>
>>>>turns 1.65 times crank CCW.
>>>>
>>>>This could be a problems (ahem, issue).
>>>>
>>>>The vacuum pump will now turn more slowly and
>>>>opposite
>>>>the way it previously turned (it previously was
>>>
>>on
>>
>>>>the
>>>>fuel pump drive).  I called SigmaTek about this
>>>
>>and
>>
>>>>they said, though the pump is bi-directional,
>>>
>>the
>>
>>>>direction change is significant because it gets
>>>
>>a
>>
>>>>wear
>>>>pattern after awhile and changing could shorten
>>>
>>the
>>
>>>>life.  I only have 12 hours on mine so they said
>>>
>>it
>>
>>>>should be OK.  The other problem is they said
>>>
>>their
>>
>>>>pump needs about 1500 RPM to get good vacuum
>>>
>>(gauge
>>
>>>>in
>>>>the green) so at 0.847:1 I'd need around 1800
>>>
>>crank
>>
>>>>RPM to get good vacuum.  Hmmm.
>>>>
>>>>The SigmaTek guy did say that other pumps on the
>>>>market only need 1200 RPM to get up to speed so
>>>
>>only
>>
>>>>would need around 1400 crank RPM to get good
>>>
>>vacuum.
>>
>>>>Still not the best situation.
>>>>
>>>>I hope to get some comments from the Franklin
>>>
>>guys
>>
>>>>to
>>>>see what ideas are out there for solving this
>>>>problem.
>>>> Can't go running around w/o vacuum.
>>>>
>>>>Sorry to be the bearer of bad tidings.
>>>>
>>>>Mike Deeter
>>>>N2011P Franklin RG E
>>>>
>>>>
>>>>
>>>>=====
>>>>*******************************************
>>>>Mike Deeter
>>>>N2011 Test Pilot
>>>>iguanamagic@yahoo.com
>>>>http://iguanamagic.siegesmund.org
>>>
> === message truncated ===
> 
> 
> =====
> *******************************************
> Mike Deeter
> N2011 Test Pilot
> iguanamagic@yahoo.com
> http://iguanamagic.siegesmund.org
> *******************************************
> 
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