---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Thu 07/02/09: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:33 AM - FW: Batteries and fuel tank capacity (David Corbett) 2. 06:12 PM - Re: Fuel system - More Questions! (TheSchultzFamily) 3. 07:48 PM - Re: Fuel system - More Questions! (rparigor@suffolk.lib.ny.us) 4. 09:12 PM - Re: Fuel system - More Questions! (ofamerica.com YERLY) ________________________________ Message 1 _____________________________________ Time: 10:33:09 AM PST US Subject: Europa-List: FW: Batteries and fuel tank capacity From: "David Corbett" My Europa has a Hawker Energy SBS 30 battery mounted behind the baggage bay. This battery has been in service for one year in the workshop, and 8.5 years flying, without any problem. Has anyone ever had to replace a Hawker SBS 30 because of lack of performance? I noticed that Nigel Charles posted a message about fuel tank capacity. I have just replaced the Avalec tank sender in "AM", and during the re-calibration process I put 68 litres in, on top of the unusable fuel. When I put the aircraft back from level flight position to the three point position, I could see through the tank top surface, beside the tank sender plate, that the tank was not full, and so put in three further litres, making 71 litres and the unusable fuel. The tank was still not full at that point, but I had no more fuel with me at that stage. (To clarify, "AM" is a monowheel). David G-BZAM 560 hrs ________________________________ Message 2 _____________________________________ Time: 06:12:46 PM PST US From: "TheSchultzFamily" Subject: RE: Europa-List: Fuel system - More Questions! Can anyone verify these "non" differential fuel pressure readings? MP = 14.3 Fuel = 4.6 MP - 14 Fuel = 4.9 MP = 20 Fuel = 4.9 MP = 25 Fuel = 6.4 MP = 30 Fuel = 9.1 MP = 39.5 Fuel = 11.6 Engine seems to be running fine with these but earlier in the process the engine was once again surging. Everyone that hears the surging thinks I have a fuel problem???? Monitoring and testing continues... Rich Schultz N262AE ________________________________ Message 3 _____________________________________ Time: 07:48:06 PM PST US Subject: RE: Europa-List: Fuel system - More Questions! From: rparigor@suffolk.lib.ny.us Hi Rich "Can anyone verify these "non" differential fuel pressure readings?" "Non" differential numbers are useless unless you know a lot more information. You need to know differential pressure going to the carb float bowls over airbox pressure to help you figure if you have a problem >>>>>>>>>>> period. Measure airbox pressure in absolute terms and fuel pressure in absolute terms and make sure fuel pressure is between 2 and 5 PSI over airbox pressure. Now when you start increasing MP tell us if it ever falls below 2 PSI. I guess if you really wanted to, if you think your fuel pressure gauge is accurate, add to it the weight of the air that is above you, then add an inch to MP pressure, now subtract what your fuel pressure gauge is reading plus the air above you, from the MP plus one inch. If you are between 2 and 5 PSI above with fuel pressure you are OK. That is the verification you can do yourself. Why don't you just buy a differential transducer from UMA and either one of their gauges or run one of yours from it? This way you can see if you have a problem "RIGHT AWAY" when something is going on. If you take off and either overboost or something else has a problem, instead of waiting for your motor to play silent night or slump, you can reduce MP till you get at least 2 PSI and can be fairly sure you can maintain that power setting. If you fly a 914 IMHO you want differential pressure information. Ron Parigoris ________________________________ Message 4 _____________________________________ Time: 09:12:20 PM PST US From: "ofamerica.com YERLY" Subject: Re: Europa-List: Fuel system - More Questions! Rich, I'll run mine or Bakers tomorrow, weather permitting, and see what my fuel pressure does. If memory serves, I start at 4 psi at idle and at full throttle still see about 4 in line, and about 10.0 off the regulator (my sender reads a little low). My gut feel is that regulated fuel pressure is going up with manifold pressure as it should, but if line pressure is going up to the regulator, that does not pass the common sense test. On ground tests, the fuel pressure goes up as the resistance goes up. Example: When I set up a fuel system, I disconnect the feed and pressure gauge from the engine fuel regulator and pump fuel through the lines past a direct reading pressure gauge (Tee'd to the aircrafts sender) and through a valve to a gas can. This allows me to filter the system, verify flow rates (by timing) and by closing off the valve, I can verify the fuel pressure, the fuel flow decreases and the pressure goes up well above 7 psi as I check flows and verify pressure readings. Note: These readings are done before the regulator. 11.6 psi indicates a strong reduction in flow if reading prior to the regulator, however if you are reading from the regulator, the regulated pressure at full power 39.5 MP is about 5 psi boost, and 11.6 psi fuel pressure is a tad high. >From Page 9.2.3 of the Rotax maintenance manual, Fuel pressure =Airbox pressure + 250hPa At takeoff performance the fuel pressure is going to be about 700hPa or around . 7bar or about 10.15 psi I'll talk to you after testing. The shop took a lightning strike and power surge, so I have only one shop phone left and it blew my shop computer, even with the surge protectors. Pretty spectacular really. Snap crackle pop all in one. I will be slow at answering emails for a few more days. Bud ----- Original Message ----- From: TheSchultzFamily To: europa-list@matronics.com Sent: Thursday, July 02, 2009 9:08 PM Subject: RE: Europa-List: Fuel system - More Questions! Can anyone verify these "non" differential fuel pressure readings? MP = 14.3 Fuel = 4.6 MP - 14 Fuel = 4.9 MP = 20 Fuel = 4.9 MP = 25 Fuel = 6.4 MP = 30 Fuel = 9.1 MP = 39.5 Fuel = 11.6 Engine seems to be running fine with these but earlier in the process the engine was once again surging. Everyone that hears the surging thinks I have a fuel problem???? Monitoring and testing continues... Rich Schultz N262AE http://www.matronics.com/Navigator?Europa-List http://www.matronics.com/contribution ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-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/europa-list Browse Digests http://www.matronics.com/digest/europa-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.