The Stovebolt Site Forums The Shop Area Engine Shop 49 chevy 216 Rochester carb

Hello all, I am missing a few screws that hold the top of the carb where the air cleaner attaches to the bottom of the carb where it bolts to the intake. I tried matching these in a hardware store but the thread wasn't anything they carried. Someone told me Rochester used a special thread unique to their company. If this is true where can I get these screws from? Thanks In advance, Dave

There is a good chance the motor or carb aren't original. I thought I tried all of the screws at the local hardware store but maybe I didn't. I think you understood me on where the 4 screws are at. The screws go through the piece that the air cleaner also attach to. I will try and track some 12-24 screws down at the local hardware store. Is a 12 series screw the same as a 3/16?

Thanks, Dave

Here's a bit more trivia for you- - - -When GM decided to produce their own carburetor for the Chevy engine, it was a major financial blow to Carter. The Carter CEO vowed to produce one million replacement carbs for Chevrolet engines and sell them through their authorized distributor network, including my father's shop. A few years later, Carter had the one-millionth carb of that series gold-plated, and presented it to GM's CEO.

"The ABC's of carburetion- - - -Always Buy Carter" was their slogan for a long time.
Jerry

Thanks to Hotrod for that little bit of history. That is fascinating.

In 1952 I believe it was, GM beefed up the Rochester B top a little. The Four screws were a size bigger and the metal under the screws was quite a bit thicker.

Thanks everyone, I will head out and get those screws today. I can't remember who told me that the rochester carb had their own unique thread but they sounded very convincing!

Bad news...just came back from the hardware store and the bolt I have is not a 12-24. It screwed a half turn in a 12-24 nut before the threads bound up. The guy used his thread pitch gauge and told me there were 28 threads per inch. Does this make sense to anyone? If you hold my bolt next to a 12-24 mine is a tiny bit more fine thread. Help!

1950 and early 1951 carbs used a 10 x 32 thread. Late 1951 the thread was changed to 12 x 28.

Jon.

Denny,
I have in front of me my GM manual on the new carburetors for 1952, publication #MTS-52-8 &9-S&M. Quoting from page 2 "For 1952, Chevrolet introduces a new improved GM Model B carburetor. Externally, this new carburetor has larger air horn screws, a thicker flange and heavier bosses. There are numerous internal improvements." I have the earlier carburetor and the 1952 model and with my units, the screws are larger on the 52.

Where can I get 12-28 thread screws from?

Where could I buy a 12-28 screw?