Whats the difference between a 2 and 4 barrel carburetor?

Question

WHATS THE DIFFERENCE BETWEEN A 2 AND 4 BARREL CARB? ARE THEY INTERCHANGEABLE?

Answer 1

yes a 2 and 4 barrel carb is interchangeable provided your intake can accomodate both

a 2 barrel carb has 2 gas jets
a 4 barrel carb has 4 gas jets

most 4 barrel carbs are mechanical primaries and vacum secondaries
mechanical primaries are smaller jets that open and close with the motion of the gas pedal (they are directly connected to the throttle cable)
vacum secondaries are the larger jets and only open when the engine pulls a strong vacum such as when you floor the throttle

Holley makes what are called double pumpers. They do not use vacum secondaries. They are 4 barrels that are directly connected to the throttle cable.

There are many combonations of carbs you can do:
you can have 3 2barrel's (6pack)
2 4 barrels
2 2 barrels (but this would be lame)

Answer 2

A 2 barrel carburetor has 2 barrels, a 4 barrel has 4 barrels.

As to interchangeability, the answer is that it depends.

You haven't said whether the care is using a fixed venturi carburetor or a variable venturi.

Most importantly, does the car have a fuel injection system?

In older cars, which do not, this is less of an issue. And often, the only problem is finding an adapter kit to drop a 4 barrel holley onto the block in place of a 2 barrel OEM carb.

You need to drop by your local auto parts store, and check the carbs available for the engine type you plan on modifying. Your engine type will be in the owners manual or may be looked up in a Chiltons Manual or other reference source.

Believe me, half the fun of modding a carb is chatting it up with the motorheads at the auto shop anyway.

Answer 3

Your question pretty much answeres itself. A 2 barrel carb has to main jets that squirt the fuel into the intake. A 4 barrel has 4 of these jets. They can be interchanged however the intake manifold is generally meant for only 1 of the 2. If you have a 2 bbl carb and want to change to a 4 bbl you may need to change the intake manifold in order to bolt up the new carb.

Answer 4

Are you sure he changed it. The 1968 Mustang with a 5.0L 302 came with a 2 barrel or a 4 barrel, depending on how it was ordered. Have you checked the vehicle plate to see what it was spec'd with originally? If it was a factory 2 barrel, then the camshaft will be different than if it came from the factory with a 4 barrel. You need to check to be sure. Then you can worry about size, heads and intakes. A 600 CFM will be more than sufficient. 1985 Mustang 5.0 had a 600 Holley, and also the 600 Holley was used on many Chevy motors. One that immediately comes to mind is the 1966 Corvette with a 327 cu in 350 horsepower motor.

Answer 5

Antique dealer. Four holes in the manifold to allow air fuel mixed by the Carburator into the engine. Or two hole manifold and 2 bbl carb. 2 bbl has to have larger holes to allow enough air to travel at high speed. While 4 bbl carb has small primary 2 bbl and much larger secondary 2 bbl in one carb. The best way to go is a 4 bbl if the engine had that set up. Not interchangable with out carb and manifold and many engines have different Cyl heads and camshafts for 4 bbl and make much more power. But that was the Stone Age. Now we drive 6.0 liter factory cars with over 400 Hp and 400 lb ft torque with fuel injection and engines last much longer.

Answer 6

A 4 barrel carb dumps 2 times more fuel into the cylinders. No they are not interchangeable. It will take a different intake manifold.

Answer 7

Multiple barrels in carbureation are designed to balance the flow of fuel and air to the cylinders. Two barrels on a V8 for example are shared between banks of cylinders. The nearer cylinder will be richer than the on further away. There is no way to balance the flow precisely except to introdue two more barrels e.g., four barrels. Now the flow can be balanced between pairs of cylinders all the way around. Hope this makes sense to you.

Answer 8

The number.

But seriously, not interchangeable.

Answer 9

the # of venturis used to mix the air and gasoline as it enters the intake manifold,,,,,,,,,,,,,,,,