Hey guys,Let me see if I convey this with some sort of reasoning. First history: I started out with aerocarb set up with a fuel pump and a regulator and ram air on a corvair. The fuel tank is vented from the very very top of the tank and sloped down hill behind the panel and out the side of the fuselage just in front of the wing about 7" up from the top of the wing on the passenger side. It is comprised of a 1/4" alum tube inside the tank and to the outside of the tank, the vent is then 1/4 " clear tubing to the side of the fuselage and then changes back to 1/4" alum. tube. The tube through the side is bent in somewhat of an crooked S shape so that it points straight into the slip stream of the fuselage. The open end faceing front is flared with the flaring tool that would normally be used to install the flared fittings for a AN-4 flared fitting. The fuel pump was removed in favor of gravity feed during first ground runs. The ram air was removed as problems showed up during taxi testing. The slight ram pressure that the vent tube picks up remains after 6 years and 660 hours. There is a fuel pressure sensor installed low in the system that reads to the tenth's of a pound. It never, even with as low as 2 gallons of fuel remaining, reads less than .9# at static. And around 1.4# in flight. I since added the fuel flow and installed it upstream of the pressure sensor. The pressures dropped but not to what i had calculated them to be. The static with low fuel is never below .8# and in flight now operates at 1.2# . The head height for pressure is 19" sitting level and certainly less in any climb. I do not have any back flow preventer installed and my opinion is something mechanical in a line that small is something that will get stuck. I got lucky and the pressures are centered around the published required pressures for the Aerocarb.Steven, I don't remember you saying what engine or what size carb, or header tank. The Aerocarb does work and I can not explain some of the problems that people have. Given that statement if i had more money 10 years ago I would have installed a ellison. My experinces with auto fuel and the Aerocarb are not good either.Joe HortonCoopersburg, Pa.---------- Forwarded Message ---------- From: "John Martindale" <john_martind...@bigpond.com> To: "KRnet" kr...@mylist.net Subject: KR> Fuel tank pick up and vent List-Post: krnet@list.krnet.org Date: Mon, 21 Nov 2011 19:07:39 +1100
I've had no experience with Aerocarbs. I suspect it might given they are reputedly a calibrated "fuel leak" but I don't know. Guess it depends on the diameter of the vent and thus the amount of pressurisation. Someone else might chime in or you should contact the manufacturer for the definitive opinion. A simple vent in a cap will leak if upside in a prang. Use an aircraft designed one. I think these have some kind of a rubber flap arrangement that prevents this. Check out Aircraft Spruce. John I will be running a areocarb on a corvair engine and was wondering if running ram pressure into the vent of the header tank will cause a problem with this carb. Should I be using just a vented cap instead. Steven Bedford Kr2s builder _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html ____________________________________________________________ 57 Year Old Mom Looks 27 Mom Reveals $3 Wrinkle Trick Angering Doctors... http://thirdpartyoffers.juno.com/TGL3141/4ecaa47a3823d36dd8bst04duc
