The link below is to an illustration from my Carter Carburetor School workbook explaining the triple venturi mentioned by Jerry above.

The experiment was conducted using several OPEN half-full glasses of water, with transparant tubes connecting one end to a vacuum take-off at a specific location in the venturi, and the other end submerged in the water.

The water head differences in the tubes demonstrates the differences of internal carburetor vacuum at various parts of the venturi.

Carter triple venturi effect

Jon

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
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