The Stovebolt Site Forums The Shop Area Engine Shop Can someone set the record straight? (Carbs)

I have a Rochester BC and although my truck idles well, it bogs down when you floor it. I've checked points, timing, fuel mixture, etc with no luck. I've looked through many of the forums and this is what I've come up with:

Rochesters are warped and leak... get rid of them.

The Holley Webber 2 barrel from Langdon's is good but looks horrible with the linkage and adapter.

Go with the Offy 2x1 with Carter Weber's if you can afford the price tag.

or TRY to find Carter YF's but good luck and go back to manual choke.

Is this about right? I'm just looking for options to replace my Rochester BC because it leaks and I can ease into the throttle but can't get good power out of it when I step on it.

Any suggestions?

Eas enough to check for warpage before you put in a kit. Could be the float is heavy, or not set right. Sounds like accelerator pump is not working.

I have the Rochester on my 261 and it works well.

I'd start looking for a Carter YF If You have a 216 model #965s has auto choke if You have a 235 it's model #966s ,It may take some time but it's worth it,I have one on My 235 and it made a world of differance.


Pete

They made millions of Rochesters and they worked, or they wouldn't have sold so many trucks and cars. A good cleaning and adjusting may be all it needs and leaking won't make it run bad. If you easy the peddle down all the way will it run with out bogging? or is it just when you stomp it open?

Joe

maybe it's not the carb.You distributor may not be advancing quick enough when you stomp on it.Try lighter springs on the mechanical advance weights,or remove one spring and take the truck for a ride

If it's bogging down with one carburetor, opening up twice as much venturi area with a 2-carb setup is going to make it twice as sensitive to gas pedal position. Carburetors mix fuel by creating vacuum in the venturi area of the casting, and anytime you give the air more places to go, or a too-big venturi, you slow down the airflow and reduce the vacuum that's causing the fuel to flow into the airstream. The result is not enough fuel, too much air, and a flat spot. If you don't have the right gear ratio (transmission in the wrong gear, or too high a rear end ratio) the problem will be much more noticeable because you've got the engine lugged down to the point it can't accelerate. Proper carburetion is simply getting the right amount of fuel mixed with the right airflow, and doing it through the correct engine RPM range to make the vehicle perform. Any noticeable departure from how the factory engineers did it with millions of engines is introducing a whole bunch of variables into the equation that will have to be sorted out one at a time. Fortunately, most hobbyists and/or hotrodders think they're a whole lot smarter than the guys who made their living building these old trucks! Good luck!
Jerry