Return-Path: Received: from [64.45.223.83] (account ) by logan.com (CommuniGate Pro WebUser 4.0.6) with HTTP id 2054288 for ; Sun, 16 Mar 2003 09:23:51 -0500 From: "Marvin Kaye" Subject: Re: [FlyRotary] Re: Fuel Injection To: flyrotary X-Mailer: CommuniGate Pro Web Mailer v.4.0.6 Date: Sun, 16 Mar 2003 09:23:51 -0500 Message-ID: In-Reply-To: <000001c2eb11$58172b40$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Posted for "Al Gietzen" : One last question came to mind as I was imagining the fuel returning to the sump tank. Is it normally a large volume of fuel that returns to the tank, or just a trickle. I ask that because I need to consider how large of a sump tank to incorporate into my fuselage. Thanks again, Tracy. Paul Conner Paul; The amount of fuel returning to the sump is the flow rate from the pump minus the amount the engine is burning. So if the pump is putting out 35 gph, and the engine is burning 15 gph you've got 25 gph going back to the sump. The amount returning to the sump is, of course, always less than what is going out, so sizing the sump may be determined by other factors. But just from the recirculating issue, the larger the better because the fuel returning has been warmed by the pumping and whatever heat is picked up in the engine compartment. I'd just guess that you'd like a sump tank of about 4-5 gallons +, or consider returning fuel to the main tank if that is reasonable. Best that the pump you chose doesn't pump more than about 1.5 times the max burn rate that you can expect; at the pressure for your injectors, which probably 40-45 psi. Al