Carburetors

While electronic fuel injection provides better fuel economy with lower emissions than a carburetor, when it comes to making power it has no clear cut advantage, as evidenced by the massive horsepower developed by carbureted racing engines. If you've modified your engine and want to upgrade your fuel system, there's no need to deal with the expense and complication of switching to EFI - we can supply you with larger or more performance oriented carburetors, or the parts needed to tune your present mixer.

Carburetors are rated in CFM (Cubic Feet per Minute), the amount of air and fuel that flows through the carburetor. When choosing a carburetor, the CFM should be matched to the engine's cubic inches, RPM range, and whether the vehicle will be used on the street or for racing. A general formula that can be used to calculate CFM is cubic inches x maximum RPM · 3456 = CFM, with the sum modified by the percentage of volumetric efficiency, about 85% for a performance street engine and 110% for a racing engine.

Using the above equation, a 350 c.i. performance street engine revved to a maximum of 6000 RPM will need a carb that flows at least 516 CFM, while the same size racing engine run to 7000 RPM needs 779 CFM. Since carburetors come in standard sizes, a 600 CFM carb will work on the performance street engine, with an 800 CFM unit needed for the racing engine. Beyond CFM there are other choices to consider like vacuum operated or mechanical secondaries on 4BBL carburetors. Vacuum secondaries are preferable for street engines, especially with automatic transmissions, because the secondary throttle plates open in response to load. Mechanical secondaries are appropriate for racing engines and manual transmission vehicles.

Another consideration is the type of choke. Racing carburetors generally aren't equipped with chokes but they're necessary for easy starting and fast warmup on street engines. There are manual, cable operated choke setups, and electric chokes where the choke plate is connected to a bimetallic coil. While most performance carburetors are 4BBLs, there are 2BBL performance carbs and both two and four barrels are commonly used in multiple carb setups, with three 2BBLs and two 4BBLs being the most common. Further carburetor variations include dual feed carbs where both float bowls are connected to fuel lines, and double pumper carbs that have an accelerator pump for the mechanical secondaries.

But if all you want to do is make the carb you have and your engine perform at their best, our digital shelves are packed with the tuning parts to make it happen. We have metering blocks, power valves, jets, metering rods and hangers, accelerator pumps, cams, and nozzles, and vacuum secondary diaphragms and springs, available as individual parts and in complete tuning kits, for all popular performance carburetors. With these parts and some time spent tuning, you can get optimal acceleration and a smooth transition between carburetor circuits as the throttle is opened, and obtain the right mixture to deliver maximum horsepower at wide open throttle.

trending

Popular Products

Customer Login

Carburetors

Carburetors

Categories

Refined by Clear all

Recently Viewed Products

Worldwide Delivery

Secure Shopping

Shop with Confidence

24/7 Help Center

Your cart