William: Thank you very much for such a detailed explanation..
You wrote: Daniel...your picture (see below) appears to show a header tank cap that once had a forward facing vent hole that has been plugged. Is the gauge wire clean and smooth...no accumulated deposits, and the hole it moves up and down through free and clear? I think so. Yesterday, when I took the photograph, I had the opportunity to check if the wire moves smooth and free and it seemed to be OK. As I wrote in a previous mail, a friend of mine has experienced some problems in his coupe, the one I took the photograph (a 415-CD) and nobody know what caused the problem. We consider it a mayor issue as an important RPM fall occurred during take off followed by an emergency landing. This happened in two opportunities, after that, the plane was on ground. I personally saw all the vents, and except that of the fuselage tank that as you said is plugged, the two other are OK, with the vents oriented forward. So, venting seems not to be the cause. What we are trying to figure out, is why the engine experimented the RPM drop when climbing, just after take off. Another thing to consider is that after the emergency landing, once on the ground, the engine worked well. What we are now thinking, is that the fail appeared because of an steep angle of climb. It will be very interesting to know if someone experienced the same problem before, and if that is the case, why that happened. I really appreciate all your time and interest in my questions and problem. Best regards to all of you. Daniel Arditi ________________________________ From: William R. Bayne <[email protected]> To: ercoupe list <[email protected]> Sent: Sunday, April 19, 2009 7:09:46 PM Subject: Re: [ercoupe-tech] Fuel Tank Plumbing, Caps & Fueling problems Hi all, I have always used the Rain-Pruf header tank gauge...one came with my first coupe. As John said, this cap has a forward facing hole to vent it, and this is the hole that a bug plugged and caused Glen Davis' precautionary landing related on April 7th to the list. I was not aware that the original nose tank gauge vented around the gauge wire. (Thanks John!) Sure enough, the cap wire hole is drilled .128 in diameter (slightly over 1/8") and the wire is .0938 in diameter (3/32"). I doubt the tank would be pressurized measurably by such venting. Something others may not be aware of...early coupes with a 5 gallon header tank should have gauge 415-48057, which has a wire measuring 8-13/16" overall wire length and the hole for the wire/vent is drilled at an angle. Those subsequent to Serial No. 2622 should have gauge 415-48186, which has a wire measuring 7-3/4" overall wire length (since April of '47) and the hole appears to be drilled 90º to the cap gasket bearing surface. The Rain-Pruf gauge descriptions appear to be "one length fits all" without regard to tank capacity. I have seen original-style wire fuel gauges fitted to Ercoupe wing tanks. If there is a factory part number for such caps, I don't have it. Presumably they should have wire length appropriate to wing tank depth below where they mount, and should vent in the same manner as the fuselage tank (i.e. around the bobber wire and not via forward-facing holes). These should NOT be used on Ercoupes with the header tank overflow line teed to separate lines connected to each wing tank. The above is why I urge owners to calibrate their gauges to indicate usable fuel remaining in the tanks installed in their aircraft, and to keep records of fuel (and oil) consumption and tach time every time the plane is filled.. Use that information to calculate average fuel burn per hour (FBPH), use the worst FBPH in the last 6 mos.-year and 100 MPH ground speed for flight planning purposes. Calculate the apparent FBPH several times en route flying cross country and actual ground speed. There should NEVER be surprises unless something breaks. Daniel...your picture (see below) appears to show a header tank cap that once had a forward facing vent hole that has been plugged. Is the gauge wire clean and smooth...no accumulated deposits, and the hole it moves up and down through free and clear? Best regards, William R. Bayne .____|-(o)-|____. (Copyright 2008) -- On Apr 19, 2009, at 12:22, Daniel Arditi wrote: > > John: > > Thank you very much for you response ! > > As I wrote today in another mail, I am trying to find out what is happening > with a friend´s coupe. > Yesterday I took a photograph of the fuselage cap, and for what you > explained, it should be OK. > > I attached the picture here just to show you how it looks. > > Best Regards > Daniel Arditi > > > From: John Cooper <[email protected]> > To: ercoupe list <[email protected]> > Sent: Sunday, April 19, 2009 1:35:29 PM > Subject: RE: [ercoupe-tech] Fuel Tank Plumbing & Caps > > > Daniel: > > > > All header tanks must have a fuel gauge. This is your primary fuel supply. > And yes, regardless of the cap, the header must be vented. > > > > If you have the original header cap with the exposed wire float the cap vents > through the same hole the wire passes through. If you have the Skyport > Rain-pruf gauge with the enclosed float there is a small hole in the leading > edge of the fuel cap that connects to the inside of the cap. > > > > John Cooper > > Skyport Services > > www.skyportservices .net >
