# What Does All Numbers Mean On A Holly Carburetor?

## How do you read a Holley carb number?

It’s like a “VIN” for your carburetor and should be hand-stamped on the front of the choke tower to the right of the vent tube on most typical Holley carbs. The list number typically is four to six digits long and may or may not have a suffix number behind it. The date code will be right below it.

## How do I know what CFM my Holley carb is?

Will a bigger carb make more power?

1. Performance Improvements stocks carbs from Holley Performance, Edelbrock and Proform Parts.
2. The formula for calculating how much CFM (cubic feet per minute) your engine requires is: CFM = Cubic Inches x RPM x Volumetric Efficiency ÷ 3456.

## How do I know what CFM my carburetor is?

The volumetric efficiency of the engines is a measurable value, and with an adequate carburetor will get the most efficiency out of the engine. The formula to calculate the amount of CFM (cube feet per minute) that a motor needs is CFM= Cubic Inches x RPM x Volumetric Performance ÷ 3456.

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## What’s the difference between Holley 4150 and 4160?

These two are very similar with the primary difference that the 4150 uses a thick metering block in both the primary and secondary while the 4160 is shorter in length and uses a thin, metering plate on the secondary side.

## How do you read a date code on a Holley?

Moving on, 0798 is our date code; Holley used a three digit up to 1973, after which they moved to the four digit code you see here. Decoding them is as follows: Three Digit – Example 763 > 7 – Year (1967), 6 – Month (June), 3 – (Third Week)

## What CFM is a Holley 4160?

Holley 0-80457S Model 4160 600 CFM Square Flange 4-Barrel Vacuum Secondary Electric Choke Carburetor.

## What size carburetor do I need for a 350?

A 600-cfm carburetor may perform quite well on a stock 350 Chevy. However, the minute you start weaving in power adders like a hotter cam, a dual-plane performance intake manifold, and aluminum heads you’re going to need 700-750 cfm.

## What happens if my carb is too big?

If the barrels are too big, the loss of air velocity means the cylinder will not fill to its full capacity. An engine with a carb that is too big will put out less Torque and Horsepower. It will be difficult to drive due to poor low-end torque. If you drag race your car, an oversized carb will produce slow 60 ft.

## What cfm carb do I need for a 454?

Because the 454 is less efficient, it doesn’t need as much cfm, so a 750cfm carb would be fine while a 650 cfm carb would be too small.

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## Did Holley buy demon?

We reported that BG Fuel Systems and Demon Carburetors were poised for a comeback in a blog earlier this week. The fact that the company was bought by High Performance Industries, the same company that owns Holley, Demon’s biggest competitor, has created a bit of a stir in the automotive aftermarket.

## How do I choose a carburetor size?

To arrive at the most appropriate carburetor choice, there’s a basic formula: engine displacement multiplied by maximum rpm divided by 3,456. For example: a typical 355ci small-block—a 0.030-over rebuild—with a 6,000-rpm max engine speed would work well with a 616-cfm carb ((355 x 6,000) 3,456 = 616.32).

## How much horsepower does a carburetor add?

After you fix what’s limiting performance, an Edelbrock Performer intake can add as much as 10 HP. The FAQ forum is a good place to ask questions. There are differences between engines and performance improvements.

## How do you adjust a carburetor?

Here’s How To Adjust a Carburetor

1. Remove the Engine Air Filter. The air cleaner and filter assembly must be removed for you to access the carburetor.
2. Locate Adjustment Screws.
3. (Optional): Hook up Vacuum Gauge.
4. (Optional): Set Baseline.
5. Warm the Engine Up.
6. (Optional): Adjust Idle Speed Screw.
7. Adjust the Air-Fuel Mixture.