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Pratt & Whitney Wasp Major XR-4360-4, Radial 28 Engine

Air and Space Museum

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    Object Details

    Manufacturer

    Pratt & Whitney

    Physical Description

    Type: Reciprocating, 28 cylinders, 4-rows, radial, air cooled, supercharged
    Power rating: 2,237 kW (3,000 hp) at 2,700 rpm
    Displacement: 71.5 L (4,360 cu in.)
    Bore and Stroke: 146 mm (5.8 in.) x 152 mm (6.0 in.)
    Weight: 1,636 kg (3,600 lb)

    Summary

    The Wasp Major was Pratt & Whitney’s last big piston engine. Although four rows in the radial configuration seems a cooling problem, the Wasp Major was effectively cooled by staggering each of its rows of seven cylinders. It was reliable in flight, but required extensive and time consuming checks at startup and shutdown.
    Beginning in 1941, the gigantic Convair B-36 strategic bomber was likely planned around this engine, which used six R-4360s along with four turbojets. The Wasp Major saw service at the end of World War II in late Boeing B-29s that were actually early B-50s, and was used on the Boeing B-50 "Lucky Lady" when it made the first non-stop around the world flight from Fort Worth, Texas, in 1949.
    Other principal applications were in the Douglas C-124 Globemaster and the civilian Boeing Stratocruiser, which was derived from the B-50.

    Credit Line

    Transferred from the U.S. Navy, Naval Supply Center, Cheatham Annex, Williamsburg, Virginia

    Date

    Circa World War II

    Inventory Number

    A19731549000

    Restrictions & Rights

    Usage conditions apply

    Type

    PROPULSION-Reciprocating & Rotary

    Materials

    Steel, Aluminum, Paint, Ceramic, Rubber, Textile, Phenolic, Preservative Coating, Copper

    Dimensions

    Storage: 273 × 162.6 × 181.6cm, 1921kg (8 ft. 11 1/2 in. × 5 ft. 4 in. × 5 ft. 11 1/2 in., 4235lb.)

    Country of Origin

    United States of America

    See more items in

    National Air and Space Museum Collection

    Data Source

    National Air and Space Museum

    Metadata Usage

    Not determined

    Link to Original Record

    http://n2t.net/ark:/65665/nv9023b9be0-6007-4428-9e6f-0224f926c2d2

    Record ID

    nasm_A19731549000

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