NACA cowling
During development, interest in the "buried engine" concept faded. Improvements in conventional streamlining, notably the NACA cowling, eliminated the need for a buried engine for improved performance. Additionally, with bomber designs like the B-17, using radial engines for power, starting to enter production, the need for new bomber designs became less pressing and the Army turned its attention to new pursuit models. For this role the O-1430 was not terribly useful, so Continental modified the basic design into a V-12, and then into an inverted-V-12, the I-1430.