Re: K-28 Smokebox pipes?

We had a discussion on these some time back. They were present on virtually all engines in the late 20's and the 30's but gradually got capped off with just the fittings remaining and then usually welded closed sometime in the 40's.
IIRC, no one seemed to know what they were for. All sorts of speculation emerged. Oil heater coil for the mechanical lubricator was one suggestion but they showed up on little engines without mechanical lubricators. Some sort of venturi arrangement for ??? was also guessed.
Bottom line, they are lost to obscurity. There's no one around any more who knows for sure what they were for.