cubdriver2
FRIEND
Love that line!Placards don't fill carbs.
A both position on the fuel selector valve eliminates this issue.
I like my Dakota Cub fuel valve with the stock system. I have my head up my ass on occasion and run on the low tank. I run 6-8 gallons of gas a lot and my stupidity was gonna bite me in the but eventually. The right tank feeds slower in cruise but I just work the valve like I did with the original when going cross country.Haven’t had time to troubleshoot any further yet, out of town for work. Regardless of what I find, I’ll probably be replacing my Univair fuel valve with a DakotaCub valve that has a “both” position.
In Post 31 there is a diagram of the fuel system. Up until now, I believed that all header tanks had an inlet were fuel flowed from the main tanks into the header, PLUS an outlet from which fuel flowed out to the engine.
I believe this diagram has enlightened me. It looks like that diagram shows only one fuel line connecting the header to the fuel system, plus a vent line. The fuel line acts as both an inlet and and outlet to supply fuel to the engine. So, under normal operations, the header fills up with fuel and and sits there on standby. If fuel stops flowing from a main wing tank, then the header will start to drain.
Am I reading the diagram right?
Would you care to elaborate on this? Differing points of view can be instructive. I like the both position for ease of maintaining balance as well as avoiding issues of unporting as described above. I can always choose to just use left or right, but can never use both if it isn't there. It is important to use either left or right when mooring a seaplane or parking sideways on a hill.I do not like the both system for a lot of reasons, but to each their own.
I would not trust any diagram/drawing/construction manual as to what the Actual fuel system design is in any of the old cub style aircraft. Through the years who knows what mods have been done to the system documented or not. Take the time to pull some panels and get a good look at exactly how the system works double check the fuel valve that you do get fuel flow when it says you should get fuel flow.
DENNY
Absolutely. Was at a large maintenance facility years ago with a Falcon 20. One of the items to accomplish on the inspection was to pull the fire handles and verify fuel flow stopped completely to the corresponding engine. Yep, pulled left handle and flow continued to the left engine. It did, however, stop to the right engine. Teleflex cables, hooked up backwards and flown that way for who knows how long.
Yikes! I shudder to think what could have happened if you had needed to use the fire handle.Absolutely. Was at a large maintenance facility years ago with a Falcon 20. One of the items to accomplish on the inspection was to pull the fire handles and verify fuel flow stopped completely to the corresponding engine. Yep, pulled left handle and flow continued to the left engine. It did, however, stop to the right engine. Teleflex cables, hooked up backwards and flown that way for who knows how long.
When the valve is in the off position are the tanks interconnected?Would you care to elaborate on this? Differing points of view can be instructive. I like the both position for ease of maintaining balance as well as avoiding issues of unporting as described above. I can always choose to just use left or right, but can never use both if it isn't there. It is important to use either left or right when mooring a seaplane or parking sideways on a hill.
The system which has the left, right, both and off positions on the fuel selector valve connects both tanks in both the both and off positions. Remember that the label on the selector valve tells you which tank(s) feed the engine. The label tells you which tank combination feeds the line which penetrates the firewall, only.When the valve is in the off position are the tanks interconnected?