PRATT & WHITNEY R-4360 WASP MAJOR

General Info

Specific Info

The Pratt & Whitney R-4360 Wasp Major was a 28-cylinder four-row radial piston aircraft engine designed and built during World War II, and the largest-displacement aviation piston engine to be mass-produced in the United States. It was the last of the Pratt & Whitney Wasp family, and the culmination of its maker's piston engine technology, but the war was over before it could power airplanes into combat. It did, however, power many of the last generation of large piston-engined aircraft.

 

The R-4360 was a 28-cylinder four-row air-cooled radial engine. Each row of seven air-cooled cylinders possessed a slight angular offset from the previous, forming a semi-helical arrangement to facilitate effective airflow cooling of the cylinder rows behind them, inspiring the engine's "corncob" nickname. A mechanical supercharger geared at 6.374:1 ratio to engine speed provided forced induction, while the propeller was geared at 0.375:1 so that the tips did not reach inefficient supersonic speeds.

 

Although mechanically reliable in flight, it developed an unenviable reputation for in-flight fires, particularly in its Boeing Stratocruiser application, and in addition the Wasp Major was maintenance-intensive. Improper starting technique could foul all 56 spark plugs, requiring hours to clean or replace.

 

Engine displacement was 4,362.50 cu in, hence the model designation. Initial models developed 3,000 hp, and later models 3,500 hp, but one model delivered 4,300 hp using two large turbochargers in addition to the supercharger. Engines weighed 3,482 to 3,870 lb, giving a power-to-weight ratio of 1.11 hp/lb.

 

Wasp Majors were produced between 1944 and 1955; 18,697 were built.

 

This engine was used in the following aircraft:

 

Aero Spacelines Mini Guppy

Aero Spacelines Pregnant Guppy

Boeing 377 Stratocruiser

Boeing B-50 Superfortress

Boeing C-97 Stratofreighter

Boeing KC-97 Stratofreighter

Convair B-36

Douglas C-74 Globemaster

Douglas C-124 Globemaster II

Fairchild C-119 Flying Boxcar

Goodyear F2G “Super” Corsair

Hughes H-4 Hercules (“Spruce Goose”)

 

 

Information Coming Soon.

 

15053 Crosswind Dr Burlington, WA 98233

 

 

 

  • General Info

    The Pratt & Whitney R-4360 Wasp Major was a 28-cylinder four-row radial piston aircraft engine designed and built during World War II, and the largest-displacement aviation piston engine to be mass-produced in the United States. It was the last of the Pratt & Whitney Wasp family, and the culmination of its maker's piston engine technology, but the war was over before it could power airplanes into combat. It did, however, power many of the last generation of large piston-engined aircraft.

     

    The R-4360 was a 28-cylinder four-row air-cooled radial engine. Each row of seven air-cooled cylinders possessed a slight angular offset from the previous, forming a semi-helical arrangement to facilitate effective airflow cooling of the cylinder rows behind them, inspiring the engine's "corncob" nickname. A mechanical supercharger geared at 6.374:1 ratio to engine speed provided forced induction, while the propeller was geared at 0.375:1 so that the tips did not reach inefficient supersonic speeds.

     

    Although mechanically reliable in flight, it developed an unenviable reputation for in-flight fires, particularly in its Boeing Stratocruiser application, and in addition the Wasp Major was maintenance-intensive. Improper starting technique could foul all 56 spark plugs, requiring hours to clean or replace.

     

    Engine displacement was 4,362.50 cu in, hence the model designation. Initial models developed 3,000 hp, and later models 3,500 hp, but one model delivered 4,300 hp using two large turbochargers in addition to the supercharger. Engines weighed 3,482 to 3,870 lb, giving a power-to-weight ratio of 1.11 hp/lb.

     

    Wasp Majors were produced between 1944 and 1955; 18,697 were built.

     

    This engine was used in the following aircraft:

     

    Aero Spacelines Mini Guppy

    Aero Spacelines Pregnant Guppy

    Boeing 377 Stratocruiser

    Boeing B-50 Superfortress

    Boeing C-97 Stratofreighter

    Boeing KC-97 Stratofreighter

    Convair B-36

    Douglas C-74 Globemaster

    Douglas C-124 Globemaster II

    Fairchild C-119 Flying Boxcar

    Goodyear F2G “Super” Corsair

    Hughes H-4 Hercules (“Spruce Goose”)

     

     

  • Specific Info

    Information Coming Soon.