Carl (et al) -- Charlie's problems did go away when we switched to a Rottenchester. But ... we also switched to a 261 engine, too, with a working heat riser flapper ...
But, back to the OP's question ... He's describing the problem I was having with a '49 3800/216 exactly. And while wrapping the carb with a piece of tin foil removed the symptoms, we still had the underlying issue of the carb icing.
The reason for *that* was the stuck heat riser flapper. Before going to a lot of trouble pulling plugs and all that, just simply check the heat riser flapper to make sure it functions correctly (not stuck and the spring is there and not broken, out of place, etc). We're pretty sure the stuck heat flapper was causing the carb icing, so wrapping the carb with tin foil to trap heat from the manifold to warm the carb does pretty much the same thing as the flapper.
I didn't see above where any mention was made of checking the flapper. I'm a big fan of checking the easy stuff first (well ... easy to *check,* difficult to fix ...
)
If you *do* have a stuck heat flapper on the manifold, you can at least get back on the road with the tinfoil beanie while you look for a new manifold ...
I kinda liked the Yankee Ingenuity look of the carb wrapped in tin foil -- it makes a statement, especially if you park next to the '70 Chevelle Supersport that's actually just a plain ole Malibu but with every doodad and chrome bit from the bling catalog slapped on it ...
