I am in the, "Unbolt the carb, rebuild it, and if the aluminum threads do strip retapp andor helicoil them," camp. It could be worse. I would not anticipate any blockage with old rubber parts will just come on out unless you blow out every fuel passageway and make certain a spray jet from a can of carb spray is able to be squirted in at one end, and comes out looking strong at the other. A partial rebuild, or just spraying of part of the carb, will likely leave you with more problems to deal with.
All this talk about crbs, tapping threads, etc., bring back a fairly relevant story about my earliest days in the auto repair sector (whether I should have been there back then or not...)
Normally, atter dishing out that sage advise in he first paragraph above I would be flippantly saying, "Go ahead, ask how I know these things." But, not today. No, today I provide some background, just to exercise my memory if for no other reason... Back when I was about 17, in 1971, I decided I just HAD to remove the oem 2v carb from my 1966 Chrysler Newport, along with the cast iron intake manifold. I had decided to "upgrade" to a 4v Holley.
I purchased a nice high rise intake manifild, and a used Holley 780 CFM vacuum secondary carb. I proceeded to tear the old carb and amifold off the engine, with my youngr brother watching intently as my "expert" hands were making magic happen right before his eyes (he was 15 1/2 at the time). The new intake manifold installed perfectly.
Well everything that needed to be done was pretty close to being done, except for installing the Holley 780 CFM Vacuum Secondary carb. All was going well, the new manifold was on (Offenhauser 360 dual plane), and it was time to install the carb studs. (At this point some other old timers know what is coming next, and are already snickering because they know what happened next). But, the threaded stud holes were not letting me run the studs into the manifold very far, anout two or three turns in, ehich even I lnew was not right. So, I decided to use my new, unused tap and die kit to clean out those aluminum holes and threads being used for the carb mounting studs. I began on the first hole and it went as far down as I dared, because I knew better than to bottom a regular tap. Success! On to the 2nd hole to retap and clean up. That was also quite tight, but it went through to the end, also. Well, the 3rd one was a little different. The tap had done its job well on holes 1 & 2. On hole 3 I felt a little more resistance, but I kept on cranking the tap into the stud hole, because that is what I had done before. I did not know to back off every ¼ - ½ turn of progress, and I began to congratulate myself for doing so good with this project. I never should have done that. “Snap!”
I was in shock for a moment. I had just snapped my tap inside the manifold’s 3 stud mounting hole. I knew I was screwed. The high carbon steel was going to make it nearly impossible to drill out the broken part of the tap in the manifold. I was screwed. Well, there were two sets of base plate stud holes. I figured the larger ones were for a much larger carburetor. So, I went down to our local speed shop and find a 4v to 4v adapter that was made for significantly larger 4 v carb on one side of the plate, and a regular size in the other side of the plate. All I had to mount the adapter plate’s larger mounting configuration to the manifold’s larger perimeter studs. Then I could bolt the Holley onto the adapter plate using the smaller perimeter bolt pattern. But, this time I was going to be more careful using the (newly purchased) 2nd tap.
I figured out how to reverse the tap’s direction as I ran it down on the larger perimeter threaded holes, and completed that with no more snapped off taps. I learned a few lessons that day:
- It is best to not fix what is not broken (hot rodding is not fixing, it’s improving!),
- Reverse direction every ¼ to ½ turn when using a tap,
- The six most dangerous words known to mankind were, “All you have to do is,”
- Quit while you are ahead.
Gee, I listed 4 lessons, but my little side story only indicates three lessons were learned. Would that, by chance, mean something additional happened? I wonder what that might have been…
Yes, “
Quit while you are ahead.” That was a lesson in need of learning as it turns out. I was feeling pretty good about how I fixed a potentially bad problem, and adding the plate under the carb did not interfere with the hood closing. What in darnation could I have done next to screw this up, after doing some crafty hacking to fix a problem? I decided that I really ought to take the broken off tap piece out of the intake manifold. It was Summer, I was out of school, and I looked in the Yellow Pages for places that sold machine shop tools. I found one, and drove out there with my younge4r brother (newly minted driver with a driving permit, I was allowed by law to be his instructor back then). I purchased a few very high carbon drill pits and we returned to the project.
My brother and I took turns using two different AC powered drill motors, and separate drill bits to drill the broken tap out. I thought I was being clever by alternating between the drill bits as that gave them a chance to not overheat and to also cool between sessions. Apparently I was not clear on my objective with my brother as his drill bit went off target and he hit some nice, soft aluminum. The next thing I heard was an, “uh oh,” from him. He had drilled on the side of the tap and into aluminum, all the way into the plenum. Worse yet, he snapped his drill bit, not leaving anything above the manifold surface to grab onto.
Well, me being the newest expert on all things automotive knew what I had to do. I tried to push, even punch, the broken bit so it would come out into the plenum where I ought to be able to grab it. (be aware, the intake manifold was now bolted onto the heads). Nope, it would not move, not one little bit. “Well, it is in there so tight that it will stay right there forever. I‘ll just but on lots of Permatex to help hold in placed in case it ever loosens up.” Famous last words, “That ought to be fine.”
The 383 fired up and ran in all its glory. I needed to adjust the carb speed nd idle mixture, which I was also an expert at doing because I read hoe to adjust a Holley carburetor in either Hot Rod magazine, or in a “How To Hot Rod You Carburetor” book published by Petersen and sold at Sears.
Apparently as the engine warmed up the hole where the drill bit was stuck began to loosen up. Suddenly the carb gave a backfire a few times in succession, then the engine gasped and died. The bad news is I was pretty sure what happened right away. The bad news is our father had just come home as I was tuning the carb, and was well aware the engine had a problem all of a sudden. He was not included in any discussion re: a Holley 4v carb and high rise intake manifold being installed in place of the original 2v carb and intake manifold. He came out to see if he could help, and noticed the new equipment. “So, is this where I tell you everything you touch seems to turn to ****?”
Yeah, he was really pissed. He had just purchased the Chrysler for me to be able to wheel around without bumming a car from he or my mother. He bought it for $500 from a friend, and it was running awful. I knew enough to check the plugs and points. It looked like it had never been tuned up. The ground electrodes on the plugs were not squared off, rather they were tapers and pointed where they were originally cut square. And the gap was sider than my gapping gauge could measure. The dwell was almost 10 degrees as the rubbing block on the points was so worn down. And the points were heavily pitted on one side, and hat a lot of arc residue buildup on the other. I had that engine running very nicely by the next day, idling nicely, a slight off throttle hesitation I fixed by rebuilding the carburetor, no more misfires, and perfect running at freeway speeds (SoCal). Yeah, I would have preferred a Mustang, ‘Cuda, or Challenger. But, this was a nice station in life car that ran well (until I decided to upgrade the carb and intake manifold).’’
Long story cut short. I was given a choice, a new car of my choosing, but I had to promise to never work on it without specific permission, or fix the Chrysler 383 and use it to work on other things once I took some classes. Fortunately I opted for the Chrysler where I would be able to work on it still. The engine was rebuilt to some high performance standards, despite being in a 2 ton car, and spent the next year learning ever more about auto repair on my test car. And I took a 2 year course series in auto repair technology (A.S. Degree), after which I really felt I would be able to conquer the world.
I then spent three years in the Army learning how to work on tactical vehicles, and when I was a civilian again I started work first at a Lincoln store that had a very slow service department, then at a local Ford store who invited me to “come on over.” They were busy, and I got to take a lot of factory training classes in person and via VCR tape. I loved working as a technician. Absolutely loved it. I was going to night school via my GI Bill and received a nice tax free stipend for doing so. I was able to afford to take my time while learning new diagnostic and repair skills that served me well for many years.
I have more stories than I have time left to tell them. All I can say is it was a wonderful ride, and I am so glad I decided to share a little sliver of my stories,
