I've always wanted to try the small-bore Rochester 2 BBL on a 235 that was original equipment on a 265 V-8. It would require some machining of the intake manifold mounting flange area, and an adapter plate welded or brazed into place. In order to function close to right, the float level would have to be raised somewhat, and the jeting and power system would need to be made a little richer. It should allow an increase in top-end RPM without seriously compromising the low-end torque or driveability. Anytime CFM can be gained with a single carb instead of hanging one or more extra carbs onto the engine, the process gets less complicated.
The 1970's-up carbs that would be suitable to adapt to a stovebolt engine have already been put to good use, the progressive-linkage 2-barrels like the Holley-Weber, for instance. The small primary venturi gives excellent low speed and midrange power, and the "half-a-4-barrel" operation of the larger secondary throttle plate gives enhanced high speed performance without the midrange flat spots common to multi-carb systems. There has to be fast enough airflow through the venturi to create vacuum- - - -otherwise, the flow of gasoline into the air stream gets interrupted, and the engine bogs, backfires, or stalls.
Jerry
Last edited by Hotrod Lincoln; 09/20/2010 1:07 AM.
