POE restriction / tube restriction

[Marx3]

Hi, I am in the middle of rebuilding af carb, and suddenly it struck me... I am not really sure which is the POE restriction, and which is the tube restriction.

In the fuelpassage from the secondary jets, sticks a brasstube.. the bottom of this is the... tube restriction?

The hole in the top of the secondary bore, just in line with the airflaps, is the ... POE restricition?

Or is the poe restriction in the bottom of the thicker brass tube that sticks in the well?

[Cliff Ruggles]

The tubes are not a restriction.  There are well restrictions in the main casting, and POE restrictions in the airhorn above, below, or in line with the secondary airflaps....Cliff

[Marx3]

Okay, so the holes in the airhorn is the POE restriction, but which is the tube restriction? what hole is supposed to be .036 according to recipe 1???

[Cliff Ruggles]

Different system.  The long thin tubes in the main secondary fuel supply get the .036" holes, they are high speed airbleeds, not POE....Cliff

[Marx3]

Ok, so, just for the record, the thin tubes in the secondary-system are the ones called tube-restrictions? Or is that only on some applications?
 Anyways, I see how they work as emulsion-tubes, since they stick out in open air at the top of the airhorn.

[Cliff Ruggles]

If they are smaller in diameter than the out tubes, they will be airbleeds, or secondary tubes.  If they are the same diameter as the outer tubes, they will be primary POE tubes.....Cliff

[Marx3]

Ok, like those carbs that has 3 tubes in each side I guess.

[Cliff Ruggles]

There are only 4 possible configurations for tubes in the airhorn that I have seen.

Most carburetors will have 4, two larger outer (POE), and two smaller inner (main bleed tubes).

Early Pontiac non Ram Air units used 4 larger tubes, two outer (POE), and two inner (primary side POE).

Ford 429 carburetors used two outer only (POE).

Some airhorns will have 6 tubes, two outer (POE),  two smaller inner (main bleeds), and two larger/long tubes (primary POE).

Hope this helps some?....Cliff

[Marx3]

Yes, that clarified things!!! thanks alot. I just finished the rebuild, and the carb will be installed very soon to be test-driven. MAN am I excited! You will hear how it turned out.