My truck is in the shop for a bunch of gasket replacements and carb work. The mechanic said there is a problem with the carb in the form of a mashed tube as shown in the attached picture. I do not know what all the parts are in the carb so I can't name it for you but hopefully you knowledgeable folks will recognize it. Is this part pressed in and can it be changed - (it's the tube on the left)? I have another junk carb that might be able to provide a donor part. Any help would be appreciated!
Today's generation of mechanics may know a lot about fuel injection but may not have the "old timer" experience for rebuilding carburetors. I really don't mean for this to sound negative or insulting but the carburetor in the picture should be familiar to a carburetor rebuilder. Let me rephrase that, your rebuilder should easily be able to answer your questions, show you the part that is damaged and advise you on how much it will cost to repair it.
If you are looking to rebuild this carburetor yourself, there is a lot of information in this forum and members who are willing to help.
The tube to the left, in your picture, is the very top of the power piston. It is enclosed (surrounded) by the main well support. When the support well support is carefully removed from the air horn assembly, there is another tube (not visible in your picture) that is soldered (maybe pressed) into the air horn. The power piston is the tube on top shown in the attached picture. It can be lifted out with your fingers when the well support is removed. Both tubes can be damaged or bent by carelessness or by disassembly by a novice like me.
The power piston can be replaced BUT there may be differences in the shape, length and part number. Your donor carburetor may need to be the same model number. Here again, your carburetor rebuilder should know and be able to answer your questions.
Last edited by buoymaker; 04/28/20212:54 AM.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Thanks for the replies! I dug out the "junk" carb only to find that the insides were pristine, looks like it had never seen gas. The throttle body had a slightly wider hole spacing and would not bolt to my manifold so we swapped it for the one on the bad carburetor which had the same hole spacing. The insides are slightly different and I guess it is for a later model Chevy. I may find out today how it runs.
The earlier trucks with a 216 engine had carburetors that had a 2-1/2" (c-to-c) mounting-stud distance on the manifold. Later trucks with the 235 engine had carburetors with mounting stud distance of 2-3/4". In general, it's not smart to swap carburetor parts unless they both are the same ID number. A 216 throttle body on a 235 fuel bowl may create an air flow turbulence at their junction.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
