The General Electric/Allison J33 is an American centrifugal-flow jet engine, a development of the General Electric J31, enlarged to produce significantly greater thrust, starting at 4,000 lbf (18 kN) and ending at 4,600 lbf (20 kN) with an additional low-altitude boost to 5,400 lbf (24 kN) with water-alcohol injection.

Originally developed by the General Electric Co. for the Lockheed P-80 Shooting Star, the J33 engine is a direct descendant of the British Whittle engine of the early 1940s. The first J33 underwent static testing on Jan. 13, 1944, just 6 1/2 months after development began.

The J33 was GE's first turbojet engine of its own design, its last all-centrifugal-flow engine; as well as the last to be used in U.S. military combat aircraft.

The J33/I-40 was General Electric's first turbojet engine of its own design, its last all-centrifugal-flow engine; as well as the last to be used in US military combat aircraft.

Two of the first GE series I-A engines, developing 1,250 lbs. Thrust each powered the Bell XP-59 in October 1942. Progressing in thrust through the series 1-14, 1-16, 1-20 of 1,400, 1600 and 2,000 lbs. The J33 began life as the 1-40 in June 1943 with …

Originally developed for the Lockheed P-80 “Shooting Star”, the J33 engine is a direct descendant of the British Whittle engine of the early 1940s. The first J33 underwent static testing on January 13, 1944, just 6 1/2 months after development began.

Jun 3, 2024 · The J33 was a licensed version of the Rolls-Royce Derwent. It was a single-shaft turbojet with a 1-stage centrifugal compressor section and a 1-stage axial-flow turbine. The -9 and -11 engines were rated at 3,825 pounds of thrust (17.014 kilonewtons) at 11,500 r.p.m.

The General Electric/Allison J33 was a development of the General Electric J31, enlarged to produce significantly greater thrust, starting at 4,000 lbf (18 kN) and ending at 4,600 lbf (20 kN) with an additional low-altitude boost to 5,400 lbf (24,000 N) with water-alcohol injection.

Mar 22, 2025 · A more powerful engine, an Allison J33-A-23 with 4,600 pounds of thrust, helped offset the increased weight of the modified airplane. Internal fuel capacity decreased 72 gallons (273 liters) to 353 (1,336 liters).

Development of the I-40 began in June 1943, with the first run achieved in an impressive six months. By Aug. 21, 1944, J-33 engines built to specifications had a probable life of 50 hours before major parts required repair or replacement.