VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 1952 vs 1954 carburetor

I did a search but could not find an answer to my question so I'll ask. My 1952 sedan had a 1954 235 engine transplanted into it. I was able to secure the original engine and will have it rebuilt and put back in the future. But for now my question is: is there a substancial difference between the 1952 Rochester autochoke carburetor and the 1954 Rochester autochoke carburetor? The '52 carb was rebuilt used on the '54 engine. The car runs fine but there is always a smell of gas. We can't find any leaks. I installed all new gas lines and a fuel pump. I was recently told, by a mechanic, that it was because of the carb difference and I should have a proper '54 autochoke installed. Before I expend the money I wanted to check w/ the experts? Any thoughts? Thanks

The first MAJOR change in the Rochester carburetor was in late 1951 and for the Power Glide cars. This basic carb. was carried over to 1952 plus the automatic choke was added. In general it was an improvement over the first Roch. carbs. Minor changes were made both in 1953 and 1954. Nothing that would make a noticable difference in the operation of the engine.....and nothing that would cause a smell of gas. By 1956 the 1956 carb. was sold as a replacement for all previous automatic choke cars.
The present problem with some Roch. Carbs. is that the bowl cover warps and a bit of gas will leat out at the front of the bowl. Some times just enough to stain and some times actullay gets wet in that area but quickly evaporates.
So to for a short answer, NO, mounting a 1952 carburetor on a 1954 engine will not cause a "smell" and both engines use the same intake manifolds, lower insulator and carb.gasket sets.

Gene, Thanks once again for the assist. I guess I'll need to check the bowl to see how true it is in surface match. The gas smell is not noticeable while driving. It is after driving and lifting the hood. The carb does have some brown staining the body. I believe you just saved me a chunk of change. Thanks!!

Does the car smell of gas when running or after a trip and parked in the garage? The carbs are open to the air and you can get gasoline smell due to vapors created when the carb percs on the warm engine. Another source of gasoline smell that I have noted is fuel leaking around the screws that hold the fuel pump top on. The gasket loses its rebound ability after while and one needs to occasionally tighten these screws. (after market pumps).

Hi glyn, yes it is after a drive and it is sitting so your point is well taken. The fuel pump is tight, I just installed a new one and there are zero leaks. I think that it must be in the carb area. For starters I will tighten everything up, clean the carb surface and then look for areas of further discoloration. I had a '52 as a kid (40+ yrs ago) and don't remember a gas smell after driving, but then again, at that time, I probably had a lot of other things on my mind other than gasoline smells.
Thanks for the assist. If I find the area of concern I'll post a followup.