Sign up now to join the JEGS email newsletter and be the first to learn about new products, special deals and e-mail only offers!
Carburetors are an essential component of many older cars and trucks. They are responsible for mixing air and fuel in the correct proportion and delivering it to the engine. However, identifying a correct carburetor on an engine can be tricky, especially if you are not familiar with the different types and brands. In this article, we will discuss the different methods for identifying carburetors, including carburetor number lookup and carburetor identification numbers.
What is a Carburetor?
A carburetor is a device that blends air and fuel for an internal combustion engine. It plays a crucial role in the engine's operation by ensuring the proper air-fuel mixture for combustion as well as controlling engine speed via throttle blades that are operated by a cable through gas pedal. Carburetors were widely used in older vehicles, and while modern cars have largely transitioned to fuel injection systems, many classic cars and trucks still rely on carburetors.
What are the Two Types of Carburetors?
There are two main types of carburetors: 2-barrel, and 4-barrel. two-barrel carburetors have two primary barrels responsible for mixing air and fuel. four-barrel versions have two primary barrels and two secondary barrels for improved performance and fuel distribution for larger engines and/or engines that operate at higher rpms.
In addition, there are three main types of carburetor designs: Holley, Edelbrock/AFB/Carter, and Quadrajet.
What is a Carburetor Number?
Most carburetors have a unique identification number that can be used to confirm its manufacturer, model number, and specifications such as CFM and factory included jet sizes. The carburetor number is typically located on a metal tag attached to the carburetor on original equipment manufactured vehicles. On most aftermarket carburetors, this ID is stamped or etched directly onto the carburetor body. The ID usually consists of a combination of letters and numbers that can denote the carburetor's manufacturer, model, and production date.
Carburetor Identification for Different Brands
Different aftermarket and performance carburetor brands have their own unique identification systems. Below are the identification methods for some popular carburetor examples.
Holley Carburetor Identification
Holley carburetors are popular among muscle car enthusiasts, and they are known for their high-performance capabilities. Holley carburetor identification numbers are typically stamped on the air horn or main body. Most "list" numbers consist of a four or five-digit number, followed by a dash and an additional one or two number suffix. This list number can then be looked up online to confirm the CFM, carburetor style, factory jet, power valve, and air bleed sizes, as well as other detailed information.
Demon Carburetors
Demon carburetors are designed for high-performance applications and come in various sizes and configurations. Demon carburetor identification numbers are alphanumeric up to nine digits long and are typically stamped or etched on the air cleaner mounting ring that surrounds the opening where air enters. If your Barry Grant or Demon carburetor doesn't have a number on the top, it will be more difficult to identify, and require help from Holley as they have acquired the brand (now called "Demon Carburetion").
- The first number will be the series of the carburetor
- The second and third numbers will be the size of the venturi
- The fourth number will be the size of the butterflies
- The fifth and sixth number will be the style of boosters
- Seventh number will be the type of fuel the carb is made for (gas, alcohol, etc.)
- The suffix will show what the carburetor was made for such as for a blower application etc.
Once the number has been confirmed it can be looked up online or you can call and speak to a JEGS tech support specialist at 1-800-345-4545.
Edelbrock Carburetors
Edelbrock carburetors are favored by many hot rod and racing enthusiasts, and they are known for their reliability and performance. Most Edelbrock carburetor identification numbers are stamped on the front ear with a four or five digit number, denoting the Edelbrock part number. This number can then be searched on the JEGS website to confirm the carburetor size and additional details.
Universal Identification Tips
If you cannot find the carburetor identification number, there are a few universal identification tips that you can use to identify the carburetor's make and model:
- Look for the carburetor brand name and logo on the carburetor body.
- Count the number of barrels on the carburetor. Most carburetors have either two or four barrels. You can narrow your search with this information.
- Measure the diameter of the carburetor throttle bores. This measurement can give you an idea of the carburetor's size and performance capabilities. You can narrow your search with this information as well.
Identifying a carburetor can be challenging, but it is essential for maintaining, repairing, and tuning to keep it working properly. By identifying the carburetor's brand and model and using the carburetor number lookup, you can ensure that you are getting the correct replacement parts and accessories you need.
4 responses to “How To Identify A Carburetor”
-
-
Hi Jim,
Adjusting the choke on your 1968 340 Cuda with a stock carburetor is a straightforward process. Your car likely has a Carter AVS or AFB carburetor, and here’s how to adjust the choke for optimal cold starts and drivability:
Steps to Adjust the Choke
Locate the Choke Housing:
The choke housing is usually a round black or silver cap located on the side of the carburetor. It will have markings or notches to indicate its position.
Check for the Type of Choke:
If it’s manual, you’ll adjust the cable connected to the choke lever.
If it’s electric or thermostatic (coil spring), you’ll rotate the choke housing to adjust.
Adjust the Choke Tension:
Loosen the screws holding the choke housing.
Rotate the housing clockwise to make the choke plate close more tightly for cold starts (richer mixture).
Rotate it counterclockwise to make the choke plate open more quickly as the engine warms up (leaner mixture).
Use the markings on the housing as a guide and adjust incrementally.
Test the Adjustment:
Start the car when cold and observe the choke operation:
The choke plate should be mostly closed at startup and gradually open as the engine warms.
If the engine runs rough or stalls, fine-tune the choke by rotating the housing slightly in the needed direction.
Double-Check Idle Speed:
After the choke adjustment, ensure the engine idles smoothly when warm. Adjust the fast idle screw if necessary.
Additional Tips
Clean the Choke Mechanism: If the choke isn’t moving freely, clean the linkage with a carb cleaner.
Inspect the Choke Coil or Cable: Make sure the thermostatic spring (if equipped) or manual cable is functioning properly.
Use the Factory Manual: Refer to your 1968 Cuda’s factory service manual for specific settings and diagrams.
Let us know if you need additional help. We are open 7 am-Midnight EST Monday through Friday and 8:00 am-11:00 pm on Saturday and Sunday. Call us at 1-800-345-4545.
-
-
Need to replace carb for 1956 Austin Princess DM4
Limousine 4 LitreVIN 12751.
Current carb. only info. on body “Stromberg Zenith Patent #137862 and others”-
Thanks for your question! The Austin Princess DM4 is a unique and classic vehicle, and it’s great to see you’re looking to keep it running smoothly.
From the information you’ve provided, it seems your current carburetor is a Stromberg Zenith, which was commonly used on many British cars from that era. The patent number you’ve mentioned, 137862, refers to the Stromberg brand’s design, but it’s not the part number you’ll need for replacement.
To replace the carburetor, here are a few steps you can take:
Identify the Exact Carburetor Model: Since the patent number doesn’t provide a precise model, look for additional identifying marks on the carburetor, such as a model number or serial number stamped into the body. If this information is not available, the original owner’s manual or workshop manual for the Austin Princess DM4 could provide details on the correct carburetor model.
Find a Suitable Replacement: For classic cars like the Austin Princess, locating an exact replacement for an old Stromberg Zenith carburetor might be challenging. However, there are several sources for vintage carburetors, such as classic car parts specialists or companies that offer refurbished or reproduction carburetors. You could also consider reaching out to carburetor restoration services that might help rebuild your existing unit.
Verify Compatibility: When sourcing a replacement, make sure the new or refurbished carburetor is compatible with your 4-liter engine. You can confirm this by checking the specifications in your vehicle’s manual or consulting with an automotive expert familiar with vintage British cars.
Alternative Modern Upgrades: If you’re open to it, some owners of classic cars opt to upgrade to modern carburetors or even fuel injection systems that provide better reliability and performance while still maintaining the car’s original character.
Hope this helps, and good luck with your restoration!
-
Leave a Reply