I'm in the process of having my '53 flathead rebuilt. I need to decide what I want to do on the intake. I'm putting an Isky mild grind cam in there and have some Offenhauser heads. Am debating between a 2 carb or 3 carb setup. Have heard that 3 can sometimes be overkill, and I won't see any increase in power from 2 to 3. I can't believe that would be the case, but curious if anyone on here has opinions on the matter? I know it's a bit more money for the 3, which I don't mind if I see some increase in performance. Plus, it just looks so damn cool!
1. Start and tune the thing with a single stock car, get carb happy and get ignition advance happy. Replace carb with each other carb, set them as good singles before you mess around. If you toss multiple unknown carbs and un-tuned ignition together and there is a problem you will go mad trying to fixxitup. When you are ready to add in the 2 or 3 setup, changing a flathead manifold is easy and quick. 2. Do basic tuning (single and multiple) with no aircleaners, as many of them are highly restrictive. Install cleaners when everything is happy, if anything changes find something better. 3. Going to a triple is crazy (I'm assuming still close to 239), but we are hotrodders and it is cool. Note that a triple can be run as a dual or single.
X2 Always start out with the stock carb. I've got a carb and manifold set aside just for this purpose. Most flatheads out there are over carbureted. AND please throw that loadamatic distributor away......
Break the engine in on the SINGLE stock carb. If the efficiency of the manifold is decent, and you do a good job of balancing the carbs, two will outperform three in most cases (other than looks) on an eight cylinder. Jon.