Carburettor Size Calculator

FAQs

How do I know what size carburetor I need? The size of carburetor you need depends on factors like engine size, intended use, and other modifications. A general guideline is around 1.5 to 2.2 CFM per cubic inch of engine displacement.

What happens if the carburetor is too big? If the carburetor is too big for the engine, it can result in poor low-end performance, sluggishness, and difficulty tuning. It might lead to a rich air-fuel mixture, affecting overall efficiency.

What size carburetor do I need for a 350? For a typical 350 cubic inch engine, a carburetor size in the range of 500 to 750 CFM is commonly used, depending on the application.

What is CFM for carburetors? CFM stands for cubic feet per minute, a measurement of airflow capacity. In carburetors, CFM indicates the amount of air and fuel mixture the carburetor can deliver to the engine in one minute.

How much horsepower will a 750 CFM carb support? A 750 CFM carburetor can support an engine producing around 450 to 600 horsepower, depending on the engine’s characteristics and tuning.

What is the ideal air-fuel ratio for a carburetor? The ideal air-fuel ratio for a carburetor is typically around 14.7:1 (stoichiometric) for optimal combustion and fuel efficiency under normal operating conditions.

How do I know if my carburetor is getting too much air? If your carburetor is getting too much air, you might experience poor idling, backfiring, or difficulties maintaining consistent RPMs.

Is a bigger carb better than a smaller carb? A larger carburetor isn’t always better. It’s important to match the carburetor size to the engine’s needs for optimal performance and efficiency.

Does a carburetor need to be airtight? While perfect airtightness is not always achievable, a well-sealed carburetor is essential to prevent vacuum leaks that can disrupt fuel and air delivery.

What’s better, a 2-barrel or 4-barrel carb? A 4-barrel carburetor generally provides better performance and efficiency than a 2-barrel carburetor due to its larger CFM capacity and better tuning options.

How much HP does a carbureted 350 have? A carbureted 350 engine can have varying horsepower depending on the specific build and modifications. Stock versions can range from around 180 to 300+ horsepower.

How do I know what jet to use in my carburetor? Choosing the right jet size involves tuning and observing the air-fuel mixture. Start with manufacturer recommendations and make adjustments based on performance and exhaust color.

How do I know if my carburetor is rich or lean? A rich carburetor might lead to black smoke, fouled plugs, and rough running. A lean carburetor could cause backfiring, overheating, and potentially engine damage.

What is the best brand of a carburetor? Several reputable brands produce quality carburetors, including Holley, Edelbrock, Weber, and Carter.

Will a 650 CFM carb work on a 350? Yes, a 650 CFM carburetor can work well on a 350 engine, depending on factors like camshaft, cylinder head flow, and intended use.

How many CFM do I need for 500hp? For an engine producing around 500 horsepower, a carburetor in the range of 750 to 850 CFM is often suitable.

What CFM is a stock Quadrajet carb? A stock Quadrajet carburetor can vary in CFM, but common sizes are around 750 CFM.

How many CFM is a Holley 600? A Holley 600 carburetor typically has a CFM rating of 600, which indicates its airflow capacity.

What air-fuel ratio is best for power? For power, an air-fuel ratio slightly richer than stoichiometric (around 12.5:1) is often used, as it provides better combustion under load.

What is the perfect gasoline-to-air ratio? The perfect gasoline-to-air ratio, known as stoichiometric, is 14.7:1, where 14.7 parts of air combine with 1 part of gasoline for complete combustion.

What air-fuel ratio is too lean? An air-fuel ratio significantly leaner than stoichiometric (higher than 16:1) can lead to overheating, misfires, and potential engine damage.