REFLECTOR: Reflector Digest, Vol 69, Issue 42

[Brooke Wolf]

That helps a bunch.  Thanks .

Brooke
Still building (forever!)


>
>
> From: "Craig and Denise Woolston" <cdwoolston at sbcglobal.net>
> Date: December 21, 2010 8:53:25 AM EST
> To: "'Velocity Aircraft Owners and Builders list'"  
> <reflector at tvbf.org>
> Subject: Re: REFLECTOR: Dukes 2 speed pump
> Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org 
> >
>
>
> We prime our 550N with 4 seconds of “high”, then start with no  
> pump.  We are at 2350’ MSL in the desert.  We definitely use “high”  
> to circulate fuel (mixture cut-off, throttle open) for “hot  
> starts”.  We use “low” on takeoff and landing for a backup to  
> mechanical failure.  I know I have forgotten to turn on “low” when  
> landing and never have had the engine quit at idle on approach and  
> our engine will idle statically around 450 rpm.  “High” definitely  
> will kill engine at any phase of flight so are switch for the “high”  
> position is guarded.  FWIW.
>
> Craig
> XL-5-FG, 550 hrs.
>
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]  
> On Behalf Of Brooke Wolf
> Sent: Thursday, December 16, 2010 4:31 PM
> To: reflector at tvbf.org
> Subject: REFLECTOR: Dukes 2 speed pump
>
> Thanks for the info Scott.
>
> The word I got from Cirrus is that they run their TCM 550N's with a  
> Dukes pump that produces 4-6 psi/19 psi.  I can't verify this  
> information but I am pretty confident of my source.
>
> My knowledge of the specifics of the 550 is quite limited, however  
> it is my understanding that they HAVE to be started with the pump on  
> in the high pressure mode.  After that, the pump is turned on only  
> in low pressure during critical phases of flight as a backup to the  
> mechanical pump.  I am told that the engine will not run with the  
> pump in high as it gets "flooded".
>
> Anybody else want to chime in?
>
> Brooke
>
>
>>
>> From: Scott Derrick <scott at tnstaafl.net>
>> Date: December 16, 2010 4:16:27 PM EST
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Subject: Re: REFLECTOR: 2 Speed Dukes Fuel Pump
>> Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org 
>> >
>>
>>
>> I used to know that as its the same for my 520. The low pressure is  
>> between 16-19 psi, The high is think was about 28-30...
>>
>> It's a b**** to get the electrical backup to work in flight because  
>> you have to change the mixture with any power/rpm change.
>>
>> I opted to go automotive(racing) single pressure 16 psi carbon vane  
>> pump, as that is the pressure you use for an in flight mech pump  
>> failure.
>>
>> I think I have the data on the Duke at the airport in the overhaul  
>> manual.  I can check it next time I'm there if nobody else chimes in.
>>
>> Scott
>> -------- Original Message --------
>> Subject: REFLECTOR: 2 Speed Dukes Fuel Pump
>> From: Brooke Wolf <bwolf1 at tds.net>
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Date: 12/16/2010 05:01 AM
>>
>>
>> Does anybody know the pressure ratings for the High/Low positions  
>> of the
>>> 2 speed Dukes fuel pump used in TCM-550 installations?
>>>
>>> Thanks
>>>
>>> Brooke
>
>
>
>
> _______________________________________________
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