I've been running the stock A manifold customized to Charlie Yapp's style for 20+ years and it is great. I first welded the second carb elbow on and it cracked a couple of times so went to braising and now no problems. The only change I still want to make is to add a hot air stove to outer carb as the intake runner is so cold cold it drips moisture on even a hot day. I would estimate about a %25 increase in power and no fuel pump with about the same MPG.
Ray, I thought there may be a problem with the outer carb running cold and had a few thoughts of how I may solve the condition. I have attached a rough sketch of what I was going to build. (Note that I bought the one I am showing in the previous picture.) I am planning to place a crescent shaped plate between the dual manifold carb flanges and the carbs to help with heat transfer? I should have it on my car by spring. The crescent shape is necessary to clear the progressive throttle linkage I am working on.
The heat transfer plate shown on the sketch that acts as a brace between the two primary passages is present on the manifold I purchased.
My thought of using a progressive linkage will lessen the use of the outer carb and maybe...if I am lucky...I will not experience the same condensation issue you have.
I am also considering eliminating the idle circuit on the second carb. With the progressive linkage, the choke and idle will be provided by the primary carb. I plan to have the second carb start to open at about 60% throttle and hopefully, the engine will not stumble due to the fuel mixture change. If I have trouble...I'll just eliminate the progressive linkage or greatly change it so the second carb comes into use just above the normal cold engine throttle setting for startup. I want the GAV setting and the choke on the primary carb to handle the needs of a cold startup.
I run a full flow oil filter (A-Ford-able) with the filter on the side of the valve chamber cover. I ordered a manifold from Charlie Yapp to use two updraft carbs and the front carb will not clear the oil filter. The side by side manifold I have and the sketched one looked period correct to my eye and solved the problem with the oil filter. Yaa..I know the oil filter is not period correct but with the filter painted antique green or black it blends in against the rest of the engine.
If you plan to use dual B carbs, the width of the manifold assembly will need to be wider and you will run very close to if not touching the hood. I designed for two A carbs and found I needed to keep them extremely close to each other to avoid having the outer carb touching the hood on my '29 Phaeton.
It's all for fun...they ran great when set up stock but there are a few of us who just can't keep from making a few changes. I think diversions keep me sane....just don't ask the "Is he sane? question of my wife or friends. Their opinions could vary on a daily basis!
Good Day!
