Carburetors: Weight or Volume? Moe in Wichita, KS Wants to Know

[moe7404]

moe in wichita ks
i started working on carburators in 1965. i read every thing i could get my hands on about carbs. all the info i got from the carb manufactors was that carbs weigh the air and fuel. but i have a couple of guys say a carb uses volume to put the fuel in a engine. so is it weight or volume? thanks.

 

[berkeman]

I'm moving this from General Physics to the ME and Aero forum, where it will get more knowledgeable feedback.

 

[Mech_Engineer]

Carburetors basically work by measuring air flow based on pressure difference, or volume flow if you want to put it that way.

The carburetor works on Bernoulli's principle: the faster air moves, the lower its static pressure, and the higher its dynamic pressure. The throttle (accelerator) linkage does not directly control the flow of liquid fuel. Instead, it actuates carburetor mechanisms which meter the flow of air being pulled into the engine. The speed of this flow, and therefore its pressure, determines the amount of fuel drawn into the airstream.

http://en.wikipedia.org/wiki/Carburetor

 

[moe7404]

moe in wichita ks
thanks for moving this subject. thanks to mech engineer for your answer. i guess i knew what you said, i just thought it ment that the air was weighed, but your answer is very good, thanks