Inliners International Forums General Discussion Engines Rochester 1 barrel carb ID help.

Just picked up a couple carbs that I want to use for a dual carb intake on my Chevy 235.
I have tried to find info online about what they are, but haven't had any luck.
I realize I was looking at the wrong marking on the carbs to see if they will be a match set. One has a serial number of 7004497-C-27. And the other is 7004516-C-17.
Anyone know what I bought, and if I can use these for a dual carb set up? What, if any, are the differences between the two?

Hogger,
For the "497" float bowl, it looks like a 235 carb, 1-9/16 throttle bore, about 200cfm at 3.0" Hg or 140cfm at 1.5" Hg.
For the "516" carb, it looks like a 216 carb, 1-1/2" throttle bore, about 175cfm at 3.0" Hg or 122cfm at 1.5" Hg, my guess.

A quick way to tell:
Measure the throttle bore.
If its 1-9/16 this is probably what U have or close to it.
If its 1-11/16 or 1-3/4, well two of those MIGHT be too big but maybe ok.
If its 1-1/2 throttle bore, some of those carbs were pretty tiny, even two of em might still be too small.

Also measure the venturi diameter if you can, with those you know the whole story.

That said, ANY pair of "B" carbs should run ok on a 235, just a question of tuning and how you put the pedal down.

google:

https://www.google.com/#output=search&sc...iw=1116&bih=805

ebay of "497" carb, implies 235cid
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=321140308475

Ebay of "516" carb, implies 216cid
http://www.ebay.com/itm/1930s-40s-50s-RE...6d6b957&vxp=mtr

Thanks for the info.
Not exactly sure where to measure, but the inlet where the top butterfly valve closes, is 1 7/8" on both. That's measuring from wall to wall where the throttle valve hits the sides of the cylinder it sits in.
Where the carb attaches to the intake manifold, they are both 1 1/2" Guessing this is standard.

1 7/8" sounds a little high from the numbers you gave me, Am I measuring the wrong area?

Hogger,
The top butterfly is the choke, I dont even measure up there, they are all pretty standard I think til the choke setup changed in ~1957.

The bottom part U measured is the throttle bore.
So the "497" carb is 1-1/2 inch, if you can measure the venturi (with the lid off) it would help but I'd bet its a 216cid carb as noted above.

The "516" carb, are you sure it isnt 1-9/16 throttle (bottom) bore? Either way, its either a 216 or 235 carb. The pair of em will be just about right for a stock 235.

This might help, super good Youtube on rebuilding these carbs, step by step:
http://www.youtube.com/watch?v=V2AINKEauVM

Gotcha. I double checked, and they are both 1 1/2" at the bore.
Not sure how I can measure the venturi without taking it apart. I'll need some different calipers.
You say they will be ok on a stock 235. I was hoping to do a mild cam with Fenton headers. Maybe even a slight bore when I do the rebuild.
Would they be too small?
And what rebuild kit am I looking for? There are so many different kinds and codes, I can't make heads or tails of them.
Also, if it makes a difference I have the "848" head.

I like to at least pull the carb lid, to see what jets are in there (and what dirt too) and where (if) the float is set, etc.
So then its pretty easy to get pretty close measuring the venturi.

Hygrade shows the same carb kit, 123A, and float FL108 if you need it, from 1932-1956 (tho Rochesters didnt appear til 1949 I think).

Well I tried the Gonkulator with a little cam and Fentons on a 235, your carbs are a little small, down about 4hp on top, you might lose a carlength at the most but I wouldnt worry about it. They are close enough, it comes down to whether your engine "likes" those carbs, if it does, youre fine.

Thats why the carbs being clean, having a good accel pump plunger, the right jets, etc, matters. Much happier if the carbs are clean & happy

Excellent! Thanks for the help.