Continued development of the O-1230 reached its peak when the engine was rated at over 1,200 hp (895 kW).
The US Navy began funding the development of the Lycoming engine.
[2] After some rigorous testing the engine's poor performance led to the substitution, before the aircraft flew, of a Wright R-3350 radial engine, which was also having technical problems but was considered to be more reliable than the H-2470.
The testing program was eventually terminated due to the poor performance of the aircraft.
[4] The USAAC was also interested in the H-2470, and installed and flew it in the Vultee XP-54 prototype fighter.