Rochester 2bbl Carbs


#1

I had to replace the Rochester 2 barrel carb on my 1966 Bel AIr with a 283. I found a part off a 1965 283 Corvette engine, everything lines up fine and I am planning on installing it soon. However there is a steel tube at the top of the carb that extends into the interior carb about an inch above the jets. It looks like it might attach to something in the vac system, but not sure. Any Ideas what to do with it? What it is for? Could I cap it or leave it blank safely?



Thank you.


#2

Where does it go exactly? Are you saying it comes out of the top of the carb body and then goes down into the carb throat? Or is it inside the throat and extends upward? It sounds to me like it might just be the vent tube for the carb bowl. Or it could be possible the Corvette carb has some sort of extra power-enrich valve. I don’t think you’ll do any harm hooking up the carb and seeing what if anything comes out or goes into this tube.


#3

That tube is the vent for the fuel bowl. Since this year did not have any evaporative fuel vapor collection system, the designer did not worry about vapors percolating into the intake system. It does not connect to anything – just leave it be.

I am surprised you found a 2 barrel on a Corvette engine. Usually those had either one 4 barrel, two 4 barrels, or fuel injection. I don’t remember if there was a three 2 barrel setup for that year. I am sure some other maven will correct me if I am wrong. If this is part of a three 2 barrel system, make sure it is the center carburator as the end ones usually did not have an acceleration pump, idle circuit, and were jetted differently.

Hope that helps.


#4

It goes in parallel near the top the tube is between the auto choke and the fuel line attachment point on the reservoir. Someone else has told me they thought it was source vac line for automatic choke, but I see no point of attachment on the boddy surrounding the coil. I hooked it up last night and nothing came out, now just worried about things going in and not having it hooked up properly might affect performance.


#5

Yeah, so no worries about dirt getting sucked into the carb? I am not sure where the guy came up with it at, he had pulled a 283 vette engine out of his hot rod originally from a 65 vette and said the carb and manifold were from the same year as he sold me them as a package. Since I was more interested in the carb and the price was low, the manifold meant nothing to me. Hooked it up last night and seems to be running well, just didn’t know what to do with the tube. Come to think of it I noticed it lacked the little breather hole on the top of the reservoir my 66 carb had. Unfortunately that one developed a hairline crack so not even a good core anymore, so I am keeping it around to teach my wife how to rebuild them and see how they work as she wants a 70 Nova and I told her she had to know how to work on them first.


#6

Yes, those carbs are a joy to rebuild - simple - little to adjust - easy to adjust - always work according to Hoyle.


#7

Cripes, I think that the storied L88 427s came with “tripower” 3 x 2 bbl!

I think by '65 the base engine was a 327 rather than 283, but who cares if the carb works.


#8

Since the 65 Vette never came with a 283 (phased out in the early 60s), I hope you didn’t get hit too hard price-wise for “Corvette parts”.

If you want to post the intake casting numbers I can look that up in my engine guide and this could provide a clue as to where the intake/carb really came from.