P-2 (company designation Model 34B) was the Army designation for the last five P-1 Hawks (Ser Nos 25-420/424) which were reengined at the factory with the 500 hp Curtiss V-1400 liquid- cooled engine in place of the standard 435 hp Curtiss V-1150 (D-12) engine which powered the rest of the aircraft in the original P-1 order. The new engine made these five planes sufficiently different from the rest of the P-1 order that the Army deemed them worthy of a different P-designation.
The first flight of the P-2 took place in December 1925. The increased power provided to the P-2 by the V-1400 engine resulted in an improvement in performance vis-a-vis the "standard" P-1 Hawk. Maximum speed at sea level was 172 mph, 151 mph at 15,000 feet. Initial climb was 2170 ft/min, and an altitude of 6500 feet could be attained in 3.5 minutes. Weights were 2018 lbs. empty, 2869 lbs. gross. Service ceiling was 22,950 feet, and range was 400 miles. The P-2 was armed with a pair of 0.30 cal machine guns installed in the upper engine cowling, synchronized to fire through the propeller arc.
However, the V-1400 engine proved to be unsatisfactory in service. After less than a year of operation, the Army converted P-2s 25-421, 422, and 424 to P-1A configuration with the replacement of the V-1400 engine by the D-12 engine of the P-1 series.
P-2 Ser No 25-423 became XP-6, the prototype for the P-6 line when fitted with the new 600 hp Curtiss V-1570 Conqueror liquid-cooled engine. The plane was assigned test number of P-494. Stripped of military equipment, it placed second (at 189.608 mph) in the unlimited event of the 1927 National Air Races. The winner of this race was the Conqueror- powered XP-6A, which had been produced by the conversion of a P-1A.
After the race, 25-423 was officially accepted by the Army on December 6, 1927. It was destroyed in a crash on February 25, 1929.
Only Ser No 25-420 remained a P-2. 25-420 temporarily became XP-2 when tested with turbosupercharged Curtiss V-1400. Top speed was almost 180 mph, but the basic shortcomings of the V-1400 engine precluded any further development.