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Fuel Selector WTB
Posted: Fri Jan 06, 2023 5:28 pm
by cess140
Looking for a four way fuel selector (Left, Right, Both,Off ) for my 1946 140. Have a three way now (Left, Right,Off)
Re: Fuel Selector WTB
Posted: Fri Jan 06, 2023 6:39 pm
by 6643
The '46 fuel system cannot be fitted with a "Both" valve without some other modifications. Certification rules require that if you can draw fuel from two separate tanks at the same time then the air spaces of those tanks must be interconnected. Those in the '46 system are not.
Without doing so, you will likely experience uneven fuel flow between the two tanks, and it is even possible for the engine to starve for fuel with plenty of fuel left in one of the tanks.
Re: Fuel Selector WTB
Posted: Sat Jan 07, 2023 6:27 am
by 8342
If you are worried about forgetting to switch fuel tanks, don't.
Give it time the engine will remind you.
Rick
Re: Fuel Selector WTB
Posted: Mon Jan 09, 2023 8:07 pm
by edidin
6643 wrote: ↑Fri Jan 06, 2023 6:39 pm
The '46 fuel system cannot be fitted with a "Both" valve without some other modifications. Certification rules require that if you can draw fuel from two separate tanks at the same time then the air spaces of those tanks must be interconnected. Those in the '46 system are not.
Without doing so, you will likely experience uneven fuel flow between the two tanks, and it is even possible for the engine to starve for fuel with plenty of fuel left in one of the tanks.
Interesting. Sierra Hotel Aerospace sells a "Left/Right/Both/Off" selector which they say is for the 120 and 140 with no year restrictions listed. I explored installing one in my 1946 but it was not plug-and-play with the fuel line configuration extant in the airplane, so passed. I guess it's actually not possibly in the '46.
Re: Fuel Selector WTB
Posted: Mon Jan 09, 2023 9:02 pm
by 6643
edidin wrote: ↑Mon Jan 09, 2023 8:07 pm
Sierra Hotel Aerospace sells a "Left/Right/Both/Off" selector which they say is for the 120 and 140 with no year restrictions listed.
They list both valves. The approval is PMA replacement by part number, so the SHA valve would have to be PMA approved to replace the original part approved for your aircraft, in your case, the L-R-Off valve, unless your aircraft was previously (properly) modified.
Re: Fuel Selector WTB
Posted: Tue Jan 10, 2023 7:17 am
by edidin
6643 wrote: ↑Mon Jan 09, 2023 9:02 pm
They list both valves. The approval is PMA replacement by part number, so the SHA valve would have to be PMA approved to replace the original part approved for your aircraft, in your case, the L-R-Off valve, unless your aircraft was previously (properly) modified.
Thanks John - as always a wealth of knowledge.
I seem to have migrated to aircraft that don't have "both" settings so my desire to have it in the 120 has dissipated.