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Discussion Starter · #1 ·
I pulled the carb off of my '63 Belair (283 V8 with the Rochester 2GC) and noticed that the driver's side port of the intake manifold and the underside of the carb had a lot of soot on it, whereas the driver's side didn't. Here are some pics.

Intake manifold:


Underside of carb:


I am about 95% sure I am going to be trading this carb in for a new or remanufactured one (it's got some serious issues with the choke, air filter bridge is missing, and linkages are pretty bad), but can anyone tell me why such an uneven pattern of grime might be happening? I'm not really sure what this channel beneath the carb is even for, so that'd be helpful to understand as well. The first time I pulled this thing off, the original carb studs had corroded down to about 50% of their original size, so I'm assuming a good bit of air or exhaust is circulating between the carb and the intake ports it sits on.

I do have some old gaskets that lead to some blue smoke on acceleration, but it gets a little better as the car warms up. I'm not sure if that alone would lead to this buildup that seems to be mostly on the even numbered cylinders. The plugs were changed about a year ago.
 

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That is for heating the carburetor with exhaust. It's called a heat riser crossover. I bet on your exhaust manifold there is ( or was ) a butterfly that had a bi-metal spring on it with a weight. This butterfly would close when it was cold and direct a certain amount of exhaust under the carb to keep it from icing up and to help stabilize the idle when it was cold. It would also heat up the bi-metal spring on the choke on the carb. The bi-metal exhaust manifold spring, once heated, would open and allow the exhaust to flow freely out of the manifold. They were notorious for seizing up and sticking. Those two holes in the bottom of the manifold would allow for the inlet and the outlet of the gasses. The gasses would flow around the bolts and would quite often result in one of the busting off when you tried to get the carb off. What a lot of people would do was to make sure the butterfly in the exhaust manifold was in the open position and then remove bi-metal spring, then wire the weight to the open position so it would just stay that way. The other way of doing correctly was to block the passage off completely with a thin piece of tin on the head side of the intake gasket where it would enter the manifold and then install a mechanical ( cable ) choke. This actually does not look all that bad for the years on it.
Good luck
 
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Just as an FYI and you probably already know this but ,,,,,,,

Blue smoke on acceleration is usually a sign of weak piston rings or gunked up oil rings. You may try an oil flush to try and free them up, or it's just getting tired. If all else fails a can or two for STP oil treatment will seal them up a bit and help till a rebuild is avail. Blue smoke after coming down a hill with the throttle off and then accelerating is most likely valve seals and a PITA to deal with but can be done without removing the heads. It is fiddly to do. Also blue smoke on start up I would suggest is the same thing, valve seals..

P
 

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Discussion Starter · #5 ·
I've been putting off dealing with it. May wait until it gets a little worse before I bother. Just got to keep feeding her oil :)
 

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I've had good luck with older engines by running a bottle of Rislone with each oil change, 4qt oil/1 qt Rislone. Try it for a while , it won't hurt anything.
 
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