Inliners International Forums General Discussion Engines Rochester B replacement?

So many choices out there. Stromberg, Carter, Zenith, etc. Which if any of these will NOT work with the stock throttle to bellcrank rod on a 235/261? Is the pivot point drastically changed on any of those that would require an alternate linkage setup similar as to what Tom Langdon does when mounting Carter/Weber’s? Thanks.

Curt B.

Simple question, but complex answer.

In general, one may group these carburetors in three separate groups:

(A) model specific replacement carburetors
(B) universal replacement carburetors
(C) O.E. (original equipment carburetors) for other applications.

Model specific replacement carburetors are designed by the manufacturer to directly replace the original model. Thus, a carburetor specified by the carburetor manufacturer to fit a 1953~1956 Chevrolet 235 P.G. SHOULD bolt onto this application, and the linkage, and air cleaner should fit with no modifications. Some slight modifications to the fuel line often occur. These units will normally provide best results of the three groups on unmodified engines.

Universal replacement carburetors are those that have a certain airflow and physical size. They often have a "clamp type" throttle lever that may be rotated 360 degrees, and the clamp screw tightened in the best location. They also often have an extermally adjustable main metering jet. These units often give best results with modified engines, or where the user must deal with the problems associated with deathanol.

O.E. carburetors for different makes will normally be the most challanging to adapt, as the calibration, linkage, and fuel lines may all be incorrect. The user may find that calibration and or/installation may be extremely difficult. This group will generally be the least satisfying to the user who is either unable or unwilling to do a LOT of tuning and modification (unless the modifications and/or calibration changes have already been made).

Jon.

With this broad application what one has, what they want, and what was originally there are 3 more variables. Maybe I need a different question. The Rochester B is acutated in the vertical plane so basically the rod goes straight up. Would it be fair to say all of the A and B types you mention above that bolt on to the stock one barrel intake are or have the capability of vertical actuation? Would it be that in the worst case you would have make a new rod from the bellcrank to carb that doesn’t rub the manifolds? Thanks.

Curt - There are a few words in the English language we try to avoid, and "all" is one of them. Others are "always" and "never".

I do believe it is fair to say that you may expect carburetors in group one to function with the original throttle linkage.

It is also fair to say that carburetors in group two can generally be made to function with the original linkage, although a 90 degree adapter may (or may not) be necessary with some of these. To eliminate the adapter, the selling vendor MUST be told the original application. To illustrate this point, Zenith offers carburetors of interest as a 228AV12, and a 228BV12 (these are model numbers). The "A" means that the choke shaft and throttle shaft are in the same plane; the "B" means that the throttle shaft and choke shaft are perpendicular to each other. Thus the linkage would be different on these, but universal replacements are produced with the same internal calibrations as both types "A" and "B".

It is extremely difficult to completely generalize an answer to your question. You need to pick a style of carburetor that you would like to use, and THEN determine the exact model of this style that would be most applicable to your specific application.

Jon.

That's basically what I was after. Thank's Jon.