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540T
03-15-2005, 12:17 PM
I have a fuel computer in my exp. cub and for years have been using just the manual engine driven fuel pump. I recently plumbed in a Facet elec fuel pump model #FCT480564 between the fuel selector switch and the gascolator for a back up. Trouble is the manual pump won't draw fuel through the elec pump if it is turned off. Not what I wanted. Somewhere I read that Maule used a Facet pump in their setup. Any one now how they have it tied into their system??? Question #2: can the engine driven pump fuel through the elec pump if it is turned off?? Thanks Tim

Fortysix12
03-15-2005, 12:32 PM
Copy the installation of a Comanche 180 plumbing and you should be good to go. I can discribe it to you if nec. . Same should be for fuel injection and carb. But any piper cherokee or similar should do the trick that has the fuel pump as well. Got to be one near you on a field to look at. The electric will push through the mechanical but your missing some plumbing.

irishfield
03-15-2005, 01:14 PM
You've got the wrong pump for series installation if it won't draw thru it. Some fawcets allow even gravity feed thru the pumps, others do not. Also pros and cons in both configurations to having pumps in series or in parallel. If parralled you need check valves on both outputs to avoid back(or circular) feed .

Steve's Aircraft (Steve)
03-15-2005, 03:01 PM
On any fuel pump system with electric and mechanical pump installation, I recommend highly to plump them in parallel to each other and NOT in series. I have personally seen 1 accident caused by vapor lock in between the fuel pumps in a series application where a parallel system eliminates this problem. There is no need for a check valve if plumbed correctly, the electric pump should have one internally.

540T
03-15-2005, 11:27 PM
Ok makes sense, I put a "T" out of the gascolator,one goes to the engine driven pump, the other to the electric. Then one more "T" at the transducer for the pressure side of the pumps, assuming that the internal checks of the pump prevents any back flow. Must be a way to check ? I'll try it out . thanks Tim

Steve's Aircraft (Brian)
03-16-2005, 05:06 PM
This is how we have the Hot Roc Pacer set up:

Install a tee on the Inlet of the electric pump and one on the Outlet of the engine driven pump. Fuel line runs from the gascolator to one side of electric pump inlet tee, other side of electric inlet tee goes to inlet of engine driven pump. Outlet of electric pump goes to one side of engine pump outlet tee, other side of engine outlet tee goes to carburetor.

Now read over three times, draw it out on paper, read again. Scratch head and draw it out again, then try it out on the aircraft.

Will try to find a picture to post.

Brian

Steve's Aircraft (Brian)
03-16-2005, 05:47 PM
A picture, not very good but the best I have for now.

http://www.cubdriver.com/photopost/data/500/213battery_and_fuel_sys_019-med.jpg

540T
03-16-2005, 11:40 PM
Thanks Steve, that tells the whole story. As it goes, a picture says a thousand words. Thanks again, Tim