what is the groove in the carb. spacer for?

[Anonymous]

What is the groove on the top of the stock carb spacer (the one where coolant flows through it) for a 200? Is this a vacuum passage for the automatic choke or something?

Do I need to make a groove on the adaptor I'm making (adapting the 1100 to a 1.75" intake). The carb. will be manual choke.

 

[66200i6]

Do you have the Mustang, Falcon ect manual? If you do, check out the vacuum advance circuit. That circuit pulls both manifold and ported vacuums into a part of the carb that is controlled by a calibrated spring and diaphragm. The little notch in the spacer is more than likely the manifold vacuum supply to that special vacuum advance part of the carb.

If you are going to another carb that doesn’t have this special vacuum advance then there is no need for the notch.

Also remember that if you get rid of the stock carb, now would be the time to go to the Dizzy. The stock distributor needs that calibrated vacuum advance to work properly.

Have fun, Ric.

 

[Anonymous]

Well, what I'm doing is adapting the stock carb (1100) to fit on a '78 head (w/1.75" intake) and keeping the Loadomatic. (I have never had any problems with it.) I have a '64 manual, but it doesn't really say what the groove is for. It does, however, say where the distributor vacuum comes from. "Vacuum is transmitted to the distributor diaphragm from two interconnected passages in the carburetor. The opening of one passage is in the throat of the venturi and the opening(s) of the other passage is in the throttle bore just above the closed throttle plate." So, apparently the groove has nothing to do with dist. vacuum??? This has me totally confused.

I thought I read on a website somewhere that this groove was for a car w/auto. choke and that it had to be kept clean. But, I can't remember right now - and could have been mistaken. I'll do some checking to see if I can find it.

 

[Anonymous]

Ok, well, I just found an answer to my question. I went back and scrutinized the carburetor section of the shop manual some more. It turns out that it is for the automatic choke. As the heated air from the heat riser enters and heats the bi-metal spring, it is exited into the intake manifold via a small hole in the bottom of the carb which sits on top of this groove.

 

[66200i6]

So that is what it was!? Those manuals are worth a million bucks.

Ric.