Hi Charlie,

All my pumps, but the Facet, are on the forward face of the Firewall, so can’t help you there.

Regarding “T” the Facet pump, Pressure will generally overwhelm volume, you can think of a large mass of slow moving fluid as being effectively a stationary pool of liquid (taking it to the extreme of no motion), so a higher pressure fluid would simply squirt into the larger volume liquid similar to as it if were a large tank). Yes, if the larger mass were moving at a much higher velocity, it might in effect offer a shearing force across the opening to the facet pump and have detrimental effect (possibly) – but I doubt you are going to have that kind of fluid velocity in your return line.

Ed

Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews, NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW <http://members.cox.net/rogersda/rotary/configs.htm>

http://www.rotaryaviation.com/Rotorhead%20Truth.htm

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*From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *On Behalf Of *Charlie England
*Sent:* Thursday, June 03, 2010 5:22 PM
*To:* Rotary motors in aircraft
*Subject:* [FlyRotary] high/low pressure pumps question

A couple of questions:

Have any of you RV-x builders considered putting your pumps on the aft side of the spar, to keep the cabin & engine compartment 'clean'? It looks like it would be possible, by using the existing holes for wire in the center section (RV-7). If not, are you just putting them under the center cover between the seats & raising it up a bit?

Also, how about running the transfer (Facet) pump's output line T-d into the main pump's return line? There should be minimal pressure, but will the high pressure pump's much larger volume overwhelm the modest Facet transfer pump? (Or, maybe venturi effect would eliminate the need for a Facet....)

Thanks,

Charlie