I purchased my 54 last August in the western part of NC. I drove it home to the coast and it ran fine for the most part. The car did develop a small hiccup/misfire/sputter while cruising as I progressed home. The car starts up easy, accelerates like a cat with it's tail on fire, keeps low temps and clean oil. When under a load of acceleration the car runs flawless. As soon as I back off and start cruising along at a speed around 50 there develops a random sputter. It is very subtle but it is driving me nuts because I know how good it can run. I have installed a new HEI Distributor, new plugs, new wires, new grounds, rebuilt the carb, and rewired the entire car throughout the last year. The problem has gotten no better. I was thinking maybe since the car was in the mountain/piedmont region of NC it's entire life maybe it was jetted for elevation. The carb has a #56 Jet in it so I don't know if thats my issue. I do know the heat exchange valve thingy on the manifold is seized open. I doubt that matters but worth mentioning. The only thing I am yet to do is a valve job and replace manifold gaskets....Thanks in advance for any help you can offer guys!
not exactly sure but you might have a valve hanging up. run a tankful of gas with marvel mistery oil in it 4oz to 10 gal it says on bottle might help clear it up. you can also add some to your oil i do about two hundred miles before each oil change. i know this crappy gas they sell doesnt help either but we have to live with that.
As I recall a 61 or 62 main set was stock. Sold my 54 about 50 years ago. Also leaky manifold to head could cause your problem.
^^Check this stuff, I had cracked insulator under carb and it did a lot of strange things. Posted using the Full Custom H.A.M.B. App!
Did a valve job today. . Every single valve was way to tight. Guess the previous owner didn't know how to adjust them. Exhaust is 018" & intake is 006" now. Idles way smoother and runs perfect now. Night and day. Thanks guys for all the input. Posted using the Full Custom H.A.M.B. App!