I posted pictures in my album of a filter that I used;
http://rides.webshots.com/photo/2232682370098611668LARbzY This is a CarQuest #CSI 87373 filter that I’ve been running on my stock 1950, 216 with a Rochester ‘B’. It is a little bit taller than the wire mesh that it replaced which requires that the 10-32 stud be about an 1/8” longer. CarQuest told me that one of the applications was for a John Deere tractor, which would be a much smaller displacement engine. I have had no problems with air flow in the 3000 miles that I’ve had it on the engine and if it were restricting the air flow it would have presented an over rich condition similar to having the choke pulled out. With in the past couple of months I’ve restored an original oil bath air cleaner of the proper vintage and have driven it for several hundred miles and have noticed no difference in the performance nor fuel mileage.
The paper filter that Tim linked to from JC is only $7.13. I’m sure that the CarQuest filter I used was more than that the one from JC might not need to have the stud extended.
Steve the problem with the Rochester ‘B’ carburetors leaking is caused by the Zinc alloy that was used in the castings. The condition is known in the casting industry as “Zinc Creep” and is caused by a granular separation at a molecular level. The problem was recognized early on by the engineers, which is evidenced by the fact that the air horn was continuously strengthened or the flange thickness increased over the more than a decade run that they used this design.
Many of the later Rochester “B” carbs had much heavier air cleaners on them and they had much less problem with leakage. Another problem area for leakage was the rather skimpy 1/4” NPT fuel inlet, which was often over tighten by people thinking that was the source of the leaking fuel. This resulted in the thread being deformed to the point that they would not seal anymore and in many cases where the tapered brass fitting bottomed out. This was also redesigned and beefed up on the later Rochester ‘B’ carbs.
If you look at the type of warpage that is seen in the air horn and bowl of the Rochester ‘B’ carbs, especially through the early part of the 50’s, you can plainly see that access weight from an air cleaner could not have caused it. Got to agree with ya Tim, this and other myths are simply unscientific and just that, myths.
Denny Graham
Sandwich, IL
