F-20 Idle and Economizer Carburetor Circuits

Anonymous-0 · Aug 5, 2009

Why did the F-12 and F-14 use a down draft carburetor and fuel pump unlike th F-20 which uses a gravity system and updraft carburetor?

Does anyone have a diagram of the F-20 carburetot internal passages especially the idle and economizer circuits?

Jeff Z. · Aug 5, 2009

Send an email to Steve Barbato. He is a good carburetor man.
Steve's email:

[email protected]

Athol Carr · Aug 5, 2009

They had to use a down-draft carburetor because when the engine was designed they did not allow enough space between the push-rods to get the spark plugs in. The spark plugs had to go on the other side of the engine under the manifold and thus the standard up-draft carburetor could not be used (you would not be able to get at the spark plugs). The 12 engine has the magneto on the right with all the spark plug cables going in a tube around the back of the head to get to the plugs. Changing plugs with a hot manifold is not too easy and normal plug socket wrenches cannot be used. With the down-draft carburetor they had to use a pump to get the fuel to it as it is not now below the fuel tank as is required for the up-draft carburetor. In the Farmall A engine, the same bore and stroke, they angled the push-rods to give enough space for the spark plugs, though only just enough, In the later Farmall A engines the space was made a little larger so that conventional spark plug wrenches could be used. The moral is, one fix to correct one mistake usually involves more fixes to correct the effects of the first fix.

F-20 Idle and Economizer Carburetor Circuits

Anonymous-0

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Jeff Z.

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Athol Carr

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