Analysis of information sources in references of the Wikipedia article "Indian Four" in English language version.
A dual-carb setup, offered in 1937, didn't help, and by 1938, the "upside-down" Four was discontinued, replaced by a new "rightside-up" design.
A dual-carb setup, offered in 1937, didn't help, and by 1938, the "upside-down" Four was discontinued, replaced by a new "rightside-up" design.