---------------------------------------------------------- Stratus-List Digest Archive --- Total Messages Posted Wed 10/06/04: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:33 PM - Re: Stratus EA-81 Cooling (Andrew SanClemente) 2. 04:44 PM - Re: Stratus EA-81 Cooling (Hinde, Frank George (Corvallis)) ________________________________ Message 1 _____________________________________ Time: 04:33:10 PM PST US From: Andrew SanClemente Subject: RE: Stratus-List: Stratus EA-81 Cooling --> Stratus-List message posted by: Andrew SanClemente Frank, I don't have a header, just the wing tanks. Currently the setup is a pump at each wing tank, and an additional inline pump on the firewall (Boost Pump). Only one tank is active at a time via an Andor selector and there is a separate pump switch for each tank and a third switch for the boost pump. Im glad to hear its not completely messed up since my airworthiness inspection is most likely going to be next week and Id hate to be re-plumbing my entire fuel system! Should I run the "boost" (firewall) pump on takeoff and landing or is just the one wing tank pump sufficient even though its at the bottom end of the allowable fuel pressure range? What exactly happens when the fuel pressure is too high at the carbs? Thanks for the information and feedback! -Andy On Tue, 5 Oct 2004 14:59:27 -0700, Hinde, Frank George (Corvallis) wrote: >--> Stratus-List message posted by: "Hinde, Frank George >(Corvallis)" > >Actually for some reason I thought you only had wing tanks...probably >been so long since I been flying with wing tanks only that I complety >forgot about the header tank. > >Secondly I had assumed from your description that you only had two >pumps...One on the firewall and one for both wing tanks. > >If you have a header the problem goes away because there is always >positive head over the firewall pump. > >If you have THREE pumps (one at the outlet of each tank and one on >the >firewall) and no header tank the problem also goes away...Except that >the firewall pump is a third level of protection (and designing to >this >level is overkill) and the fuel pressure will go too high when two or >three pumps are run. > >Personally I would remove the firewall pump if you don't have the >header. > >The important thing here is to NOT suck on the fuel and have a >redundant >pump that will also not suck on the fuel.....One pump at the outlet >of >each tank is fine. > >Also make sure each pump is fed from a separate electrical source (I >have two electrically isolated batteries, one ignition and one pump >fed >from each battery) > >Hope that helps > >Frank > Frank, I don't have a header, just the wing tanks. Currently the setup is a pump at each wing tank, and an additional inline pump on the firewall (Boost Pump). Only one tank is active at a time via an Andor selector and there is a separate pump switch for each tank and a third switch for the boost pump. Im glad to hear its not completely messed up since my airworthiness inspection is most likely going to be next week and Id hate to be re-plumbing my entire fuel system! Should I run the boost (firewall) pump on takeoff and landing or is just the one wing tank pump sufficient even though its at the bottom end of the allowable fuel pressure range? What exactly happens when the fuel pressure is too high at the carbs? Thanks for the information and feedback! -Andy On Tue, 5 Oct 2004 14:59:27 -0700, Hinde, Frank George (Corvallis) wrote: --=A0Stratus-List message posted by: Hinde, Frank George (Corvallis) frank.hinde@hp.com Actually for some reason I thought you only had wing tanks...probably been so long since I been flying with wing tanks only that I complety forgot about the header tank. Secondly I had assumed from your description that you only had two pumps...One on the firewall and one for both wing tanks. If you have a header the problem goes away because there is always positive head over the firewall pump. If you have THREE pumps (one at the outlet of each tank and one on the firewall) and no header tank the problem also goes away...Except that the firewall pump is a third level of protection (and designing to this level is overkill) and the fuel pressure will go too high when two or three pumps are run. Personally I would remove the firewall pump if you don't have the header. The important thing here is to NOT suck on the fuel and have a redundant pump that will also not suck on the fuel.....One pump at the outlet of each tank is fine. Also make sure each pump is fed from a separate electrical source (I have two electrically isolated batteries, one ignition and one pump fed from each battery) Hope that helps Frank ________________________________ Message 2 _____________________________________ Time: 04:44:45 PM PST US Subject: RE: Stratus-List: Stratus EA-81 Cooling From: "Hinde, Frank George (Corvallis)" --> Stratus-List message posted by: "Hinde, Frank George (Corvallis)" If you use the 106 pump (not the 105) it will give you about 3.5psi at full power which is just fine. The boost pump makes way too much pressure and does nothing to avoid vapour lock. The Andair selector is redundant and unnecessary...just switch pumps to switch tanks...sooner of later you will get confused which pump goes with which valve position. I just have an on/off valve (for impending crashes) and non return valves on the discharge of the pumps (I also have a filter for each pump here) so the contents of one tank don't end up in the other. Run both wing tank pumps on take off. Because the pumps are in parallel they will not double the pressure like what is happening now. Too much pressure means eventually you will flood the carbs because the fuel pressure will overcome the float valve...Maybe not now but in time this could happen. If you remove the boost pump you will also remove some pressure drop which will bring your pressure up a bit at the carbs Run both on takeoff and you will also get another 1 psi or so. I never rely on just one pump on take off. Frank -----Original Message----- From: owner-stratus-list-server@matronics.com [mailto:owner-stratus-list-server@matronics.com] On Behalf Of Andrew SanClemente Subject: RE: Stratus-List: Stratus EA-81 Cooling --> Stratus-List message posted by: Andrew SanClemente --> Frank, I don't have a header, just the wing tanks. Currently the setup is a pump at each wing tank, and an additional inline pump on the firewall (Boost Pump). Only one tank is active at a time via an Andor selector and there is a separate pump switch for each tank and a third switch for the boost pump. Im glad to hear its not completely messed up since my airworthiness inspection is most likely going to be next week and Id hate to be re-plumbing my entire fuel system! Should I run the "boost" (firewall) pump on takeoff and landing or is just the one wing tank pump sufficient even though its at the bottom end of the allowable fuel pressure range? What exactly happens when the fuel pressure is too high at the carbs? Thanks for the information and feedback! -Andy On Tue, 5 Oct 2004 14:59:27 -0700, Hinde, Frank George (Corvallis) wrote: >--> Stratus-List message posted by: "Hinde, Frank George >(Corvallis)" > >Actually for some reason I thought you only had wing tanks...probably >been so long since I been flying with wing tanks only that I complety >forgot about the header tank. > >Secondly I had assumed from your description that you only had two >pumps...One on the firewall and one for both wing tanks. > >If you have a header the problem goes away because there is always >positive head over the firewall pump. > >If you have THREE pumps (one at the outlet of each tank and one on the >firewall) and no header tank the problem also goes away...Except that >the firewall pump is a third level of protection (and designing to this >level is overkill) and the fuel pressure will go too high when two or >three pumps are run. > >Personally I would remove the firewall pump if you don't have the >header. > >The important thing here is to NOT suck on the fuel and have a >redundant pump that will also not suck on the fuel.....One pump at the >outlet of >each tank is fine. > >Also make sure each pump is fed from a separate electrical source (I >have two electrically isolated batteries, one ignition and one pump fed >from each battery) > >Hope that helps > >Frank > Frank, I don't have a header, just the wing tanks. Currently the setup is a pump at each wing tank, and an additional inline pump on the firewall (Boost Pump). Only one tank is active at a time via an Andor selector and there is a separate pump switch for each tank and a third switch for the boost pump. Im glad to hear its not completely messed up since my airworthiness inspection is most likely going to be next week and Id hate to be re-plumbing my entire fuel system! Should I run the boost (firewall) pump on takeoff and landing or is just the one wing tank pump sufficient even though its at the bottom end of the allowable fuel pressure range? What exactly happens when the fuel pressure is too high at the carbs? Thanks for the information and feedback! -Andy On Tue, 5 Oct 2004 14:59:27 -0700, Hinde, Frank George (Corvallis) wrote: --=A0Stratus-List message posted by: Hinde, Frank George (Corvallis) frank.hinde@hp.com Actually for some reason I thought you only had wing tanks...probably been so long since I been flying with wing tanks only that I complety forgot about the header tank. Secondly I had assumed from your description that you only had two pumps...One on the firewall and one for both wing tanks. If you have a header the problem goes away because there is always positive head over the firewall pump. If you have THREE pumps (one at the outlet of each tank and one on the firewall) and no header tank the problem also goes away...Except that the firewall pump is a third level of protection (and designing to this level is overkill) and the fuel pressure will go too high when two or three pumps are run. Personally I would remove the firewall pump if you don't have the header. The important thing here is to NOT suck on the fuel and have a redundant pump that will also not suck on the fuel.....One pump at the outlet of each tank is fine. Also make sure each pump is fed from a separate electrical source (I have two electrically isolated batteries, one ignition and one pump fed from each battery) Hope that helps Frank == direct advertising on the Matronics Forums. == == ==