The CFM rating for a Holley 4150 series carburetor varies depending on the specific model, commonly ranging from 750 CFM to 780 CFM.
Understanding Holley 4150 CFM Ratings
The Holley 4150 is not a single carburetor with one fixed CFM, but rather a series or configuration of squarebore carburetors featuring metering blocks on both the primary and secondary sides. This design is highly versatile, and within this family, different specific model numbers carry distinct CFM ratings.
Key CFM Variations of the Holley 4150 Series
Historically, one of the most well-known carburetors within the 4150 configuration is the Holley 3310. This particular part number underwent a slight CFM adjustment over its production lifetime.
- Original 3310 (Early Production): These carburetors, recognized as part of the 4150 configuration, were initially rated at 780 CFM.
- Later 0-33310 Versions: Subsequent iterations of this carburetor, designated as 0-33310, were calibrated slightly differently and assigned a rating of 750 CFM.
The following table summarizes these common CFM ratings associated with the Holley 4150 series:
| Holley Model Designation | CFM Rating | Description |
|---|---|---|
| Holley 3310 (Original) | 780 CFM | An early, widely recognized aftermarket part number in the 4150 configuration. |
| Holley 0-33310 (Later) | 750 CFM | A revised version of the 3310, maintaining the 4150 configuration. |
Why the Variation?
The slight difference in CFM ratings between early and later versions of what is essentially the same style of carburetor often comes down to internal calibration changes. These can include modifications to components like booster venturis, main well restrictions, or air bleeds, made by the manufacturer over time to optimize performance, improve fuel economy, or meet specific market demands.
Identifying Your Holley 4150's CFM
To determine the precise CFM of a specific Holley 4150, it is best practice to check the carburetor's list number. This number is typically stamped on the air horn or the side of the main body. Once you have the list number, you can cross-reference it with Holley's official documentation or product catalogs for an exact specification.
