---------------------------------------------------------- Kitfox-List Digest Archive --- Total Messages Posted Wed 09/04/13: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:43 AM - Re: Fuel Flow thru Facet pump (mikeperkins) 2. 08:29 AM - Re: Re: Fuel Flow thru Facet pump (SWeidemann@aol.com) 3. 08:50 AM - Re: Fuel Flow thru Facet pump (mikeperkins) ________________________________ Message 1 _____________________________________ Time: 07:43:01 AM PST US Subject: Kitfox-List: Re: Fuel Flow thru Facet pump From: "mikeperkins" Mike, All header tanks are installed with the same intention: insure fuel flow in 1) a dive, or 2) with one tank empty and the other tank unported due to a slip or skid. Once upon a time, in the Model 1 and 2 days, fuel lines were commonly being routed uphill, over top of the door and then down between the windshield and the door, then back up to a firewall-mounted header tank. The biggest problem with this installation was requiring the fuel to go uphill over the doors because of the extremely low head pressure, or even negative head pressure, at that point in the system. Pulling fuel like this with a pump leads to vapor lock. Vapor lock is often associated with high temperatures, so thinking of it as an expanding "gas bubble" might be a better way to look at it. Anyway, to get around the problem of unreliable fuel flow, folks were resorting to installing primer bulbs over the doors, which had their own problems, and the whole thing was getting messy. The switchover to the rear-mounted header tank arrangement occurred about 1990. The intention was to encourage routing that kept the fuel constantly going downhill immediately after leaving the wing tanks to prevent vapor lock. I switched my system over from the old way to the new way after it had all been plumbed but not flown. When I installed the rear-mounted header tank, I also added a valve just above the seat between each wing tank and the header tank. And I installed a main shutoff just forward and below the left door. The system has worked well for 400 hours. -------- Mike Perkins Havana, Illinois Model I, 532, B gearbox, GSC prop Read this topic online here: http://forums.matronics.com/viewtopic.php?p=408004#408004 ________________________________ Message 2 _____________________________________ Time: 08:29:43 AM PST US From: SWeidemann@aol.com Subject: Re: Kitfox-List: Re: Fuel Flow thru Facet pump I agree with Mike's question. Why is a header tank necessary for such a system (Kitfox with low behind the seat header tank) where gravity should take care of ALL your fuel pressure needs? I have an ancient Luscombe with wing tanks that uses Mother Nature's Gravity System and has no fuel pump anywhere. Sko ________________________________ Message 3 _____________________________________ Time: 08:50:36 AM PST US Subject: Kitfox-List: Re: Fuel Flow thru Facet pump From: "mikeperkins" The Luscombe's updraft carb is located much farther below the wing tanks than the the Kitfox's side-draft carbs. So the Luscombe's head pressure at the carb is going to be a lot higher, and so will the gravity fuel flow rate. That's my guess anyway. -------- Mike Perkins Havana, Illinois Model I, 532, B gearbox, GSC prop Read this topic online here: http://forums.matronics.com/viewtopic.php?p=408012#408012 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kitfox-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kitfox-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kitfox-list Browse Digests http://www.matronics.com/digest/kitfox-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.