flyrotary@lancaironline.net Mailing List Archive

Charlie, For what it's worth, your proposed fuel system is essentially the same as I am using with the exception - that I have a very small (like 1/2 pint) header tank at the junction of your "T". But, I see no reason to believe that you proposed set-up would not work perhaps even better - no header tank on the FWF to absorb engine heat. Mine has worked for 10+ years. However, I would suggest that you include a facet pump between the tanks and your set up - probably after your selector valve - for a couple of reasons. In the early days of my testing when I was doing power on stall testing, I discovered the combination of high power settings and low air flow through the cowl - could get my fuel in the header tank hot enough to percolate - never got vapor lock, but I could see the fuel pressure varying considerably and the engine would complain. Turning on the facet pump apparently provided sufficient pressure to stifle the percolation. Plus it sort of "ensures" that you have a pump that will "Pull" fuel out of the tanks. I always have it on for take off and landing. FWIW 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://www.rotaryaviation.com/Rotorhead%20Truth.htm -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Charlie England Sent: Sunday, June 06, 2010 9:47 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: high/low pressure pumps question Hope this helps... On 6/6/2010 2:21 AM, Todd Bartrim wrote: > > Hi Charlie; > Hmmmnn, I gotta say a picture (or drawing) is worth a thousand words. > Todd (sent on my new-fangled google phone with a really damn small > keyboard) > >> On 2010-06-05 8:46 PM, "Charlie England" <ceengland@bellsouth.net >> <mailto:ceengland@bellsouth.net>> wrote: >> >> Hi Todd, >> >> My thought is to set up the fuel path thus: fuel source through a T >> into injection pumps, through filters, through combining T, through >> the regulator(in cockpit), through firewall to engine. The >> regulator's bypass port (in the cockpit) would be plumbed just like >> yours, except no heat exchanger since the bypass fuel would never see >> the heat of the engine compartment. The bypass would still T into the >> supply to the injection pumps, like your system. Obviously, a >> manifold pressure line would be required through the firewall into >> the cockpit to the pressure regulator. >> >> My original plan (different injection that didn't require a return >> line) was similar to your selector setup: main tanks feeding stock >> van's selector, with the 3rd port on it being fed by a 2nd vans >> selector to select either of the 2 aux tanks. No transfer pump would >> have been required, & no crossover valve. Failure of the primary >> valve could have been a 'show stopper', but the newer valves seem to >> be rock solid reliable. Going to this system using the gear type >> pumps requiring a return line forced re-thinking. Using your idea to >> return the bypassed fuel at the pump inlet effectively eliminates the >> 'return' issue, & tempts me to return to the original fuel selector >> layout, with the addition of a Facet boost pump. The fact that the >> optical sensors will work looking into the side of a fuel line (the >> T), instead of needing them in the tank & that they still give almost >> a full minute's warning, is very encouraging. I'll start looking for >> a convenient place to mount them. >> >> I hope that Tracy will chime in on how he plumbed the regulator on >> his -8. >> >> Many thanks for the extra details. >> >> Charlie >> >> >> >> On 6/5/2010 12:32 PM, Todd Bartrim wrote: >> >> > >> > Hi Charlie >> > Not sure I understand correctly what you mean? Can you >> sketch it out quickly? I'... >> >> > *From*: Charlie England <ceengland@bellsouth.net >> <mailto:ceengland@bellsouth.net> >> <mailto:Charlie%20England%20%3cceengland@bellsout. >> <mailto:Charlie%2520England%2520%253cceengland@bellsout.>.. >> >> > *Subject*: [FlyRotary] Re: high/low pressure pumps question >> > *Date*: Sat, 05 Jun 2010 08:38:09 -0... >> >> >> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: http://mail.lancaironline.net:81/lists... >>