Of the three engine manufacturers who were left in business after the signing of the Armistice at the end of WW1 (Curtiss, Wright and Packard) only Curtiss had been involved in the manufacture of aircraft engines before WW1. Except for a few experimental engines, all were water-cooled types, and these were not built in large quantities until 1914 when the UK Government ordered severeal hundred of the 90hp OX engine. A slightly larger 100 hp OXX engine was also produced but these OX and OXX engines were only suitable for trainer aircraft, and were obsolete by the end of the war.
Curtiss OXX-3 Aero Engine
Curtiss OXX-3 Aero Engine
Curtiss K-12 Aero Engine
Curtiss K-12 Aero Engine
Curtiss K-12 Aero Engine
Curtiss V-2 Aero Engine
The Army had in the meantime produced a specification for a new engine, known as the R-1454. The specification was issued on 15th August 1923. The development of the engine itself had been carried out by the Army through Wright, Lawrance and an independent engineer, S.D.Heron, and had been through many changes to the cylinders in particular. The fixed-price contract was won by Curtiss following its bid of the 13th November 1923 , and was for the construction of three engines with an option for three more. The first engine was delivered in September 1924, and it gave up to 405hp at 1650 rpm. A modified cylinder developed by Heron (Type M) was fitted to the engine, and the Army instructed Curtiss to proceed with the other engines called for under the contract in February 1926.
The appearance of the lighter Wasp engine from Pratt & Whitney effectively killed off the R-1454, and the Army and Curtiss agreed to terminate the contract almost at once. Curtiss then started development of the H1640, a two-row 12-cylinder engine which it hoped would capture the market for an engine in the power range of the Wasp, by having a smaller frontal area. Curtiss never recovered its position as a major engine manufacturer after this period, and left the field open to Pratt & Whitney and Wright Aeronautical in the big air-cooled radial engine markets. It did have continuing sales of the water-cooled Conqueror engine, sales which produced quite good profits for the company, and which in dollar terms equated to purchases of air-cooled engines by the Army. In 1932, Conqueror purchases by the Army equated to two thirds of expenditure on engines of this size.
In 1929, Wright and Curtiss merged to become the Curtiss-Wright Corporation.