Hello. Finally my 66 Skylark GS returned from Missouri to Denmark. It is very nice and absolutely rustfree and the engine runs very well. But there's always something to do with an old car. It is equipped with a Carter ABF Competition carburator, no. 9755S 2808. Does anybody know where I can get some information about this carburator? Links to articles or the like? Obviously it is not the original one. I have the Chassis manual and this number does'nt occour in the list. I would also like to know if this carb is a good choice for my 401 engine. Best regards from Crazy-Dane. :TU:
9755s is an aftermarket replacement square bore carburetor with electric choke designed for a hot rod 454 Chevrolet. You will have several issues in trying to make it work on a 401; specifically, a hesitation from a dead stop (if you have an automatic transmission), and probably a severe bog when the secondary is engaged. I would consider it a very poor choice for a 401 (unless the 401 is in a trailered race car, not to be street driven). If a trailered racecar, then it can be made to work, if cost is not an object. You will need a "strip kit", a "spring kit" and a secondary airvalve from a "donor" Buick AFB; as a bare minimum for tuning. More information - with no offense meant, it should be AFB (A)luminum (F)our (B)arrel rather than ABF. The 2808 means the carburetor was built on the 280th day of some year ending in an "8", probably 1998. Jon.
So what would you recommend? Hi Jon. Thank you for your prompt answer. Ok, it is bad choice for my 401! So what should I go for if I want to replace it? Any aftermarket carbs that would be suitable? Or should I go for one of the original ones that came with the car when it was new? Is Rochester a better choice than Carter for a 401 in a 66 Skylark GS, automatic transmission? If one is preferred over the other, then I would like an explanation. Both are mentioned in my big thick manual. I intend to use my car in the street and participate in car meets and maybe race it on the strip a couple of times - it is not a competition or race car and I want to keep it original since it is an unmolested matching numbers car. Jette
Jette - the Rochester 4-G series was designed in 1951 for use on 1952 models. The design was somewhat upgraded through the years until 1966 which was the last year for this model (it was replaced by the Q-Jet). The AFB was designed in 1956 for use on 1957 models. Carter continued to make this model through the mid-1980's until Carter was purchased by Federal Mogul. Federal Mogul redesigned the AFB to allow it to be made cheaper and thus sell cheaper (with less reliability). These newer versions are vacuum castings (the originals were pressure), have slab throttle shafts (the originals were slotted), and other modifications. These units are calibrated for Chevrolet, and need major modifications to make them perform well with Buick engines. Edelbrock took over the Federal Mogul AFB's. The point to the above was to illustrate that the AFB was a newer design. Now, opinion: If the engine remains stock, there is very little difference in performance from the original 4-GC to the original AFB, with a slight nod to the AFB. Since you possibly plan to race the car on the strip a few times, the AFB would have a significant advantage as one can easily slip in slightly richer metering rods (if you have them) to fatten the fuel curve slightly at the strip. If you do not have the rods, this becomes a moot point. The rods are no longer available from Carter, and thus must be custom-made. Few shops have the necessary tooling to make these rods, as the tolerances are +/- 0.00002 inches. We do make these rods, but the equipment is old (so is the machinist ) and slow (ditto the machinist), thus the rods are expensive. If you have a machine shop in Denmark with this capability, it is easy to determine the specifications. Remember that the effective metering area is the area of the jet less the area of the rod. The rod has both a "high vacuum" and a "low vacuum" diameter. To "fatten" the mixture by say 5 percent; figure the effective area of the jet/rod combination at each diameter, add 5 percent to the area, and then reverse the equation to get the required diameter of the rod. I would vote for trying to find a stock 1966 Carter AFB; and before someone accuses me of trying to "grind my own ax" as I sell older carburetors - I don't have one. Maybe someone else on this board can help; and while ebay is always an alternative, it is my belief that a member of this forum might be a better choice if one has the carburetor you need. A little additional information. Many years ago, we set up a 401 on a friend's 1966 Skylark convertible with a pair of Carter AFB carbs (part number 9400). These ran like a "scalded dog" and had such street manners that his wife took the keys, and he had to build another one for him :grin: Jon.
Carter talk Wau, you sure know something abour carbs!! :TU: I will post a request in this forum and on the Danish Buick Club forum and see if I get any offers. There is a man down in Florida ( who is also a member in this forum )that found a storage building with 6 og 7 '66 Grand Sports some months ago, and a lot of spare parts. He bought the lot and I will start asking him. If I find something that needs to be rebuilt my husband is good with his hands and he loves challenges, so I am confident that my problem will be solved, one way or the other. Our holiday plans include a visit to the Annual Buick Meet in Rochester, Minnesota and there might also be a chance that there's an original Carter for sale on the swap meet. I am grateful that you took the time to explain all the details concerning carburators. You sound like you know what you are talking about. Thanks again :beer Jette
