I decided to do a carb swap before installing a dual quad set-up and noticed the heat passage on the stock manifold was filled with carbon. Once it was cleaned out the engine developed a stumble at idle. It felt almost like a vacuum leak as I needed a much higher parked idle. On installing the 2x4 manifold and carbs the stumble disappeared. I notice the manifold does not have the holes into the exhaust passage. Despite what some people said about two stock carbs needing "major modification to work" quite the opposite is true. The car runs better with two carbs than one! I used an edelbrock progressive linkage and it fits like it was made for the carter set-up. Cheers :beer
Actually (sorry, didn't catch your name), I just bought one of those 7094 Edelbrock linkage sets for my new dual "performers" (500cfm this time). I was out there installing it last night and I'm not really happy with the length of the lower stainless bar that is attached to the rear (primary) carb. It's a bit short for me. Unless I have it set up wrong. It looks simpler to install than it is. Lots of fiddling around (read: sore back). I don't suppose you have any pics of your throttle linkage so I can see how you line up? Two pics would be great. One at idle and another at W.O.T. would be ideal so I can compare. I've sort of got it working but the two rods are not in the both brass blocks at W.O.T. The rod that attaches to the rear car exits and re-enters the brass block at about 3/4 throttle. It seems to line upo ok but I'm concerned that one day it won;t slide back into the front brass block and will stick my throttle open. I've tried distorting it so see if I can get it to stick but it goes in and out very great ease and smoothness. I'm half tempted to try it out but as they say "if it doesn't look right, then it's probably not". This just doesn't look right to me. I'm heading out into the garage (car hold?...lol) to have another look at it and will snap a few shots to show. Those shiny Edelbrock carbs and all that cad plating looks like a pirates treasure chest. Very schparkly. Just on another note I also was surprised with how well the car drives with multiple carbs. I was also expecting a headache but the only headache I have is getting them to run their best. But to just start and drive down the road with traffic is a breaze. The progressive linkage means that basically I run it like four mechanical primary barrels. The second (front carb) comes on at a time of my choising by adjusting the stop that activates the front carb travel (the front carb is the secondary for those who don't know). "Pure mechanical secondaries" I call it and it satisfies most of the acceleration expectations I have of this car. One thing is definately sure. If I had to choose between one single four barrel carb or two sets of primaries (and no secondaries) on a dual carb setup, I'll take the dual two barrels any day. Especially in a stock Nailhead.
Bill..........did I understand you correctly? I thought you said your progressive linkage opens your rear carb first.....does that include the secondaries on the rear carb opening before the front carb even begins to work? I would think that would cause fuel distribution problems.......I always thought some cylinders on the stock dual quad Nailhead have a tendency to run lean and the others run rich? Setting it up like you have it might make that condition even worse. The stock setup has the rear primaries opening first, then the front primaries, and then the rear secondaries begin to open, and lastly the front secondaries. I think the throttle lever on the front carb is a little longer than the one on the rear carb to allow the secondaries on the rear carb to open before the secondaries on the front carb. :Smarty: BTW, those carbs look awesome! A pirate's treasure chest was an excellent way to describe that :TU:
No, it opens just as you described it. Rear primaries, then front primaries, then the rear secondaries, then the front secondaries. Opening the secondaries doesn't do much but it sure makes a nice sound. Tomorrow, I'll try both carbs on full, see how it behaves.
