Working on assembling my 8BA motor. I have the rebuilt (by a professional) carbs on the manifold (carbs also marked 8BA) and noticed there is a threaded port on each that seems to be missing something. I had two junker carbs of the same type and they were missing it too. Looking at carbs for sale on line some seem to have a brass plug threaded in there and others do not. Not sure what it is called, blown up parts diagrams I have found don't seem to call attention to anything that fits in there? So, what should be in there if anything? Can I run without it? If no, where can I get two of them and what's it called ? Thanks !
There is nothing missing. Any carb with a brass fitting in there is either a mistake or an attempt at a repair. That orifice requires a special compression fitting called (appropriately) a "Ford Nut". They are available from several sources. I believe "Third Generation Auto Parts" in Tennessee is one. That port is to control the advance on a Ford "Load-a-Matic" distributor. This is a type of advance system that is unique to Ford during the period and requires a special carburetor and distributor that work together. I see you mentioned "carbs" (plural) in your post. Be advised that the "Load-a-Matic" system will not work properly on anything but a "bone stock" engine. If you haven't already done so, you should familiarize yourself with the unique properties of the 8BA system.
Here is the 8BA carb I ran on my 8BA when using a Mallory mechanical advance distributor. Notice the use of the brass plug to block off the vacuum advance port .
True, but common practice. Had a much celebrated carb rebuilder tell me he mists his rebuilds with Eastwood carb spray. Did not want to get into hassle of using dichromate.
Do you by chance recall where you obtained said plugs? I am running dual carbs on a mildly hopped up motor with a Bubbas hot rod distributor so not using the original set up as noted.
Dave Tatom was the guy who rebuilt them, probably among the last things he did before he became I'll and then passed away.
Gergstuff; That plug was already installed on the carb when I bought the carb. They are 1/8-27 brass plugs that you can buy on line or at NAPA. You can make the saw kerf with a hacksaw blade or thin cut off wheel, if desired. 1/8-27 brass plugs - Search (bing.com) The plugs are almost 1/4 inch thick and the bottom is flat with a slight taper for starting the plug in the threaded carb hole. You could even make a plug out of another 1/8-27 fitting if you cut off and solder the hole closed ( See last photo.). Be very careful when you screw in the plug as the threads strip easily. DO NOT OVER TIGHTEN. It should start to fit easily by hand. Here are some photos I just took showing 1/8-27 pipe thread tap and die and plugs. Use oil on the threads. You could also use a 1/8-27 Nylon plug. That way there is no chance of stripping the carb threads. Look here: 1/8-27 nylon plug - Search (bing.com)
Do you know of someone who does chromate? I have several carbs that I would like done; not rebuilt just the body's DI-chromated. before Covid I was in contact with a shop in Montana (I believe).
Joel: Check this out. Yellow dichromate carburetor refinishing services? | The H.A.M.B. (jalopyjournal.com)
Thanks 19fordy, nylon sounds like a good way to go. I live in a small town and the NAPA is not very well stocked, will probably have to order on line.
So if I was running 3 of these on my Y block with a '59 non- load-a-matic dist, where should I get the vacuum for the advance? Manifold? To plug this port in the two end carbs, I made plugs from 3/8" fine thread bolts. I used stainless allen button head bolts that I cut very short so they seal on the outer edge. they are not long enough to touch anything down in the hole.
Since this is a traditional hot rod forum with an orientation towards performance, manifold vacuum would probably be best. Some engines run what is called "ported vacuum". derived from the carburetor, but that is more of an economy thing. "Ported vacuum" is not the same as "venturi vacuum" used in the "Load-a-Matic" system.
Since those carbs do not have a ported vacuum option, you have to run manifold vacuum. Note that you set initial timing with the vacuum advance disconnected and the vacuum line plugged. Once you connect the vacuum line, you will have to readjust the carburetors since the idle rpm will increase.
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