flyrotary@lancaironline.net Mailing List Archive

Thanks Steve !!..........Perhaps just another "Non-Problem" for our fuel systems..............Possible but not likely

unless fuel is returned directly toward the pump inlet as you stated...........

Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold

From: Steven W. Boese <SBoese@uwyo.edu>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Tue, June 8, 2010 2:33:19 PM
Subject: [FlyRotary] Re: high/low pressure pumps question

Kelly,

When the statement was made that the air would eventually be eliminated through the vent, I didn't mean to imply that it was necessary to have this happen. It would be best to avoid drawing the bubbles directly into the fuel supply line which would only happen if the fuel was returned very close to the supply inlet. On one wing tank, I have the return entering center of the root rib about a foot away from the supply inlet. For the other tank, the return outlet is next to the filler cap which is always above the fuel level and as far away from the supply inlet as is possible. No difference in operation of the two tanks has been noticed.

A reason given for returning the fuel below the liquid level has been to reduce foaming. There may be other reasons. I haven't seen much tendency for gasoline to foam under conditions present in my system.

Steve Boese

RV6A, 1986 13B NA, RD1A, EC2

From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of Kelly Troyer [keltro@att.net]
Sent: Tuesday, June 08, 2010 11:26 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: high/low pressure pumps question

Guys,

Very enlightening and truly food for thought to those of us still in the construction stage...........I have just

one more question to ask............Previous info seemed to indicate that return fuel should be entering the

fuel tank at the bottom or at least close to the bottom.............In light of Steve's observations would it

seem reasonable that air bubbles in the return fuel would be eliminated to the tank vent faster if the return

line was at the top or close to the top of the tank ??................

Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold