Editing Choosing a carburetor

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==Selecting carburetor size==
The higher the engine can rev, the greater the required CFM. However, bottom end response worsens with increased CFM.

===Based on displacement and use===
For a street engine, a general rule is 1.5 to 1.7 times the displacement equals the necessary carburetor CFM. For a competition engine, it can be up to 2.0 or 2.5 times the displacement.

===Based on RPM and volumetric efficiency===
Another way to figure carburetor size is with this formula: RPM x CID/3456 x VE. (VE = volumetric efficiency).

A basic, run-of-the-mill engine might have 85% volumetric efficiency. A well planned-out motor can achieve 100% volumetric efficiency, and finely-tuned racing motors can reach up to 120% volumetric efficiency.

==Selecting carburetor type==
''this section needs additional opinions and confirmation''

Opinions vary on the choice between vacuum secondaries and mechanical ("double pumpers"). However, generally speaking:

*Gas mileage is better with vacuum secondaries.
*Mechanical secondaries are generally best suited to light, manual transmission vehicles.
*Mechanical secondaries are preferred for racing applications.
*Mechanical secondaries are more difficult to tune.

==Selecting carburetor brand==
''basic explanation of the various brands goes here. should include: parts availability, quality, difficulty in tuning, price, etc.''

==References==
*http://www.hotrodders.com/forum/carburetor-size-162801.html
*http://www.hotrodders.com/forum/vacuum-vs-mechanical-secondaries-131129.html

==See also==
*http://www.ford-trucks.com/article/idx/18/140/article/How_to_Choose_your_next_Carburator.html
*http://www.thirdgen.org/pickacarb
*http://www.classictrucks.com/tech/cl_0312_choosing_carburetor/index.html