Hi Everyone,
I've got a vacuum port question. But first the particulars... The engine is a 235 built in 1959 and equipped with hydraulic lifters. It was originally hooked to a castiron powerglide transmission. The engine is currently not installed in my truck. I hope to do a swap between the currently installed, nonfunctional engine and this one sometime this spring/summer. Although not installed, it does run while sitting on my engine stand. The engine came to me with a Rochester 1 barrel. After reading lots of posts about the pros and cons of Rochester carbs, I decided I'd look for a Carter and give it a try. So I found a Carter 3211S, which is supposed to be an aftermarket carb designed for my vintage of 235 engine and I bought it.
I also read a lot about whether these had vacuum ports or if you needed to use the manifold vacuum port for the distributor advance. I thought that the consensus was that these carbs did not have the distributor vacuum ports on the base. This carb has 2 openings on the base, one of which is threaded, one of which is plugged. Here is a pic of the
Carter 3211s base with threaded opening . Here is a pic of the
inside of the base with 2 openings visible. One is horizontal and one is vertical with the horizontal opening is just to the right of the vertical opening in the pic. When the bottom butterfly is closed, the openings are below the bottom butterfly. In the first pic, you can see 1 opening and 1 plug. I haven't touched the plug, but it clearly is an opening from the outside to the other opening inside the carb.
The question is: are these vacuum ports for use in operating the distributor advance? If not, what are they for and should I be using them or plugging them?
Here's a
closeup of carb model numbers to show the 3211s and the number of the base.
Here's a
closeup of underside of the base showing all of the openings.
Here's a
different view of the openings showing the plug and threaded opening.
Thanks for looking!
