Is a Rochester Quadrajet a good carb?
A lot of good and bad has been written about the use of a Rochester Quadrajet carburetor as a replacement four-barrel. Some enthusiasts love them while others avoid them like the plague. The truth is, a properly tuned Quadrajet can be just as efficient and reliable as a bolt-on substitute performance carburetor.
What CFM is a Rochester Quadrajet?
750 CFM
Quadrajets can range anywhere in between 600 and 800 CFM. Most are rated 750 CFM or higher. Quadrajets are used by many GM street car enthusiasts; however, they are also disliked by just about as many.
Do they still make Rochester carburetors?
In 1995 Rochester became part of Delphi, which in turn became a separate company four years later, and continues to manufacture fuel injection systems in Rochester, now part of General Motors Automotive Components Holdings- Rochester Operations.
Who made Quadrajet carbs?
Rochester Carburetor Division
The Quadrajet four-barrel carburetor was produced by the Rochester Carburetor Division of General Motors from 1965-’90. It was produced in many forms, including electronic-control from 1980-’90, for a wide variety of GM applications.
What year did GM stop using carburetors?
Chevrolet introduced a mechanical fuel injection option, made by General Motors’ Rochester Products division, for its 283 V8 engine in 1956. It has become the primary fuel delivery system used in automotive engines, having replaced carburetors during the 1980s and 1990s.
What causes a carburetor to bog?
The “Bog” simply means the engine is not receiving enough fuel when you go to wide open throttle. While there are other issues that may cause similar reactions within the carburetor, often the problem can be traced back to the accelerator pump system. Incorrect adjustment is the typical culprit.
Are all Quadrajet the same cfm?
Most Quadrajets were capable of 750 cu ft (21,000 l)/min (cfm) maximum, but some rare Buick and Pontiac models were capable of 800 cu ft (23,000 l)/min for use on high performance engines, and most 1984-1987 pickup trucks were also equipped with the 800-cfm carb.
Are all Quadrajet carbs the same?
All Rochester Quadrajet carburetors are identified by a seven- or eight-digit GM part number. Carter Carburetors built Quadrajet carburetors for GM cars from 1966 into the late ’70s. If the Quadrajet you’re looking at has a seven-digit part number ranging from 702 through 704, these were built before 1976.
Are Rochester carburetors good?
In its stock form, the Rochester Quadrajet carburetor often gets a bad rap, but with a bit of work, it can be a very capable performer. The long-discontinued carburetor remains popular with performance rebuilders and tuners.
What does Quadrajet mean?
The Quadrajet is a “spread bore” carburetor; the primary venturis are much smaller than the secondary venturis. Most Quadrajets use a vacuum operated piston to move the primary metering rods to control the air-fuel ratio, allowing the mixture to be lean under low load conditions and rich during high load conditions.
