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We are getting ready to install the wing fuel tanks (either 13 or 13.5 gallon fiberglass) and have a question about the placement of the fuel shutoff valves. The plans call for mounting the shutoff valves behind the pilot's heads. We are not really pleased with that placement as they might be a little difficult to see/reach in flight. Has anyone modified their placement and if so, where did you put them. Thanks in advance!!
Jay
Which model kit is it? The early ones called for that placement but a later service bulletin changed that due to fuel flow problems.
It is a model III with a mod to model IV speedster wings. Serial #925. I'll take a look through the service bulletins again. I want to keep them close to the wings - so we can stop a leak if it happens nearest the source, but really don't want them behind my head.
The general wisdom is you want to avoid any restriction / pressure drop in that area. If you do put in valves there, make sure they'll pass the full line size and can't trap any air. They also changed from the cylindrical aluminum header tank behind the dash to a poly header behind the seat at that time. These too proved to be problematic (leaks). Fingers crossed, but that's still what's in my plane. Best to go with an aluminum header tank down low behind the seat somewhere and possibly an electric Facet pump for backup.
Jay,
There being no direct answer to your question so far, I offer what I have done with the shut-off valve. I read lots of discussion on these forums on the placement before making my decision. I also recall the report on what led to loss of control by John Denver. I would not consider a fuel shut-off that takes my attention away from the attention to flying the airplane. My model IV valve was originally centered under the instrument panel requiring a lot of fuel lines running behind the panel.
To get the fuel shut-off easy to reach with eyes straight ahead, I ran my fuel line from the tank behind the seat through the facet pump there, down along the underside of the pilots door... Along with only antenna and pitot tubes... to a shut-off valve in the wall next to my left leg then along the inside of the cabin side of the firewall across to the right side and through the firewall with a fitting then to the gascolator. All electrical lines run elsewhere including aft through the area below the passenger (right) door. No electrical wires traversing along fuel lines and the shut-off reachable without looking.
My own personal approach for what it's worth.
Bud
IV 1200 nearing completion
912 powered
I have ball valves off each tank behind me. I just reach behind and open or close on the pilot side, has never been a problem. the right tank is easy to reach, better on that side. I use one tank at a time so I can keep fresh fuel all the time. I use alki fuel. I also have a main turn off under the panel. I never turn that off. well I do it when I replace the filter. ha, in line paper one. from carquest. just make sure you have the valve before the filter. :D I keep an eye on it for junk and water, never seen water, but junk yes. I replace it generally on an oil change. every 50 hrs.
Appreciate everyone's responses! We'll talk it over and post what we finally come up with some pictures. Thanks again!
Jay
Single Weatherhead valve center console. No other valves. (Visible upper left in the picture.) Why would you add more valves?
Several reasons, I started with the single console valve , but added a valve between each wing tank to header tank on my IO-240 powered Series 5 after a few years of flying my plane. 1) never liked the way fuel would feed from one tank until it was almost dry before the other tank started to feed. I used to slip or skid in cruise to balance the tanks. Now i can balance fuel by by closing one of the new valves. 2) On one of my early trips to OSH , I saw a parked Kitfox peeing fuel out of one (low wing) its fuel cap vent. Anytime you park on any kind of slope or uneven ground , the tank fuel will self level and with enough fuel in the tanks, you will start to lose it overboard. This will limit your ability to fuel up , until you are ready to leave if not on level ground. Now I park and shutoff one valve to isolate the tanks and this will no longer happen. 3) Maintenance- there are times I isolate a tank for maintenance items , for example , I use colored cork balls in my sight gauges to better show the fuel level , and one got stuck so I drained one tank instead of both to fix this. Or to check my low fuel warning system by shutting both wing tank valves and draining header tank to see if lite comes on. (before I used to have to drain all fuel to check this.) So as you can see there are good reasons for more valves in a the kitfox fuel system. Now make sure if you go this route redo your static fuel flow check to the engine to assure the valves haven't reduced your flow below the 150% limit. Bruce N199CLQuote:
Originally Posted by Guy Buchanan