carb info

[Sensei]

Is the quadrajet on an L-81 supposed to have a secondary vacuum brake? I got my car a year ago and have had a frustrating problem with bogging at WOT. The enigine seemed unmolested so I assumed it was all there, but as I have been studying the E4ME I have seen pictures with a secondary vacuum brake that my car does not have. Every picture of an L-81 engine I can find has the air cleaner on so the carb does not show. On page 355 of the assembly manual the drawing shows a secondary vacuum brake, but on previous (less detailed)pages it does not seem to be there. On page 355, it is the little doo dad just above the line pointing to "BRACKET (6N)", and below the "4" inside a square. If someone could take a look on their car and let me know if they have one I would really appreciate it. Thanks and God bless, Cris Kolb

 

[Sensei]

Here is some more info on locating the secondary vacuum brake for those who may not have the assembly manual. It looks like a gold colored flying saucer and would be mounted on a bracket that sticks out toward the fire wall on the passenger side of the carb. It looks a bit like the primary vacuum brake, which is on the front of the carb on the passenger side. Again, I am trying to find out if the L-81 came stock with a secondary vacuum brake. To see it, all you would have to do is take off the air filter housing. Thanks and God bless, Cris

 

[MMM]

Cris,
I checked my reference books for the Rochester Q-Jet model numbers the '81's with which the '81's were originally equipped. I found the following:
Automatic (49 State) - 17081228
Four-speed (49 State only) - 17081217
The Delco-Rochester Service Bulletins covering these model carbs (Bulletin 9C 14021 for carb 217 and Bulletin 9C 14022 for carb 228), do NOT indicate that either model carb was originally equipped with a secondary vaccum break system.
Hope this helps,
Mike