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I just add two new tanks side by side to the original ones and is experiencing lack of fuel down to the gascolator when the external tanks got empty (enttraped air to the fuel line) causing an engine malfunction. To solve that touble I want to direct the fuel lines (4) to the header tank - I suppose to install it below the pilot seat. To be sure on the right device cnstuction I want to hear from you the header tank specification. Thanks in advance
Waldo PU-MSW Sao Paulo Brazil
That's a lot of plumbing you want to do! How are the tanks being fed now? Is each wing tank feeding it's neighbor or is there two seperate lines from each wing tanks going into one line? If the outboard wing tank was feeding the inboard tank both would empty at a steady rate, then all you would need is a 2 way valve to control fuel for each wing.
I was planning on four tanks and a header as well, but the header was only being considered because I'm looking a fuel injected engine. If I wasn't going to use the header, then I was looking at a 5 way valve (one "on" for each tank and a off position) on the console. It would take a bit of fuel management but not worse than other planes I've seen.
I've seen some headers that fit under the front panel, but I agree I'd rather have it under the seat. Some sit in the rear side of the baggage compartment, A recent Viking installer went that route. The tank is visible from the pilot seat by just looking over your shoulder and has a site tube on the side so you know how much fuel is in the tank with just a glance. Seems like a good idea. Here are his pictures of his tank install...
Hi Mark Thanks a lot for the spending time an attention!
What we did:
1- Assembled 2 outboard tanks (same volume to the vicinity inboard tanks)
2- Connected itselves (pair to pair) thru an "Y" aluminum connection just in the side to the inboard ones and put an one-way valve to avoid feul transfer to the I/B to the O/B
3-Kept original plumbing from that Y to the Gascolator
4- Added 2 vent hoses from the top of the O/B tanks to the wing tip (down side)
Finished the job, full fueled all the tanks and flew for hours in testing without any kind of problems!
So was happy up to the moment we (my wife and me) experienced an engine flame out at 6500 feet returning to a trip that last 2 hours the total leg that means the O/B tanks were almost dry (remained 5 liters each O/B)
As soon e got the engine malfunction the electrical pum was on and restarted the engine, declared emergency to the control and set-up the plane for an emergency landind. The nearest airport was 6nm and I approached it. There was a city between us and the land strip. I had to bank turn and reapproached in a safer way. Suddenly (when I turn) the engine experienced malfunction - was pretty rough and did not accept trottle! anyway I was in a high descent rate to direct land strip approach as authorized by the Tower and the proppeler did not stop due to an inertial movement and restarted by itself! and landed safely. Very strange what happen in the next steps.! When was taxying to the hangar area the engine was 100% perfect - 3200 RPM no signs of wrong things
Called Jabiru Dealer for assistance, return home back by bus (7 hours!) A week later returned back for trials ( did no fill the tank due to the remained ammount was enough to return back. by the way I hired an expert pilot to test. after 25 minutes flying over the airport he experienced flame-out again!!! We fill the tank up to the top flew 1 hour and nothing happen - everything good. The pilot approached home and after on hour again engine malfunction new emergency stop etc. Decided to close the new plumbing flew back with I/B original tanks and after 1 hour test refill again and approached home. Now the bird is on her nest and we are redesigning the fuel lines. We will take in account your advise! Thank you so m uch and congratulations
Sorry for the long story! rgs waldo
Forgot to say that the problem was a differential pressure between tanks vents avoiding fuel goes down, admitting air bubbles instead!
The Viking Engine Header Tank. Mounts below seat, used on many 750's.
Here is a diagram of the 701 header that sits below the luggage compartment.
Here's a link to the CH750 Header Tank installation:
For more info go to: