Feb

Dakota Territory Air Museum P-47 Mounting the R-2800

February 24, 2022

The Double Wasp is mounted on a stand as the QEC (or Quick Engine Change assembly) is completed.

Mounting the overhauled R-2800 is a major milestone in the restoration of P-47 42-27609. It nearly completes the visual impression of this largest single-engine WWII fighter.

The Pratt & Whitney Double Wasp R-2800 used in the P-47 is an eighteen-cylinder, double-row radial weighing approximately 2350 pounds. The cylinder bore is 5.75 inches and the piston stroke is 6 inches. The cylinder volume swept by all 18 pistons combined is 2804 cubic inches.

For a rough analogy of the sheer size of the cylinders, consider that at 155.7 cubic inches (or 2.55 liters,) each cylinder displaces slightly more than the entire standard 4 cylinder engine in a Toyota Camry or Ford Fusion.

The cowl flaps have been mounted on the rear cowling support ring.

The variant of the Pratt & Whitney used in the P-47D-23RA is the R-2800-59

The Dash 59 had General Electric magnetos shown here. The Dash 59 variant used a single-stage, single-speed supercharger integral to the engine. Additional boost came from the complex ducting connecting the General Electric C-23 turbosupercharger to the engine-mounted supercharger. Water injection anti- detonation ( ADI) also boosted horsepower to 2,300 when war emergency power was used.

The oil coolers are installed in zinc chromate painted mounting frame.

The bare aluminum cowl support rings are prominent in this photo. The cowl flaps are already attached to the rear ring.

As the QEC assembly was done, many connections to engine accessories had to be made. Visible here are hydraulic lines with blue yellow blue tape coding, and the large uncoated metal oil line leading downward from the green painted oil tank in the center of the image.

The inner cowl baffling between the cylinder rows of the R-2800 Double Wasp is visible here.

Here is a detail shot of the rocker covers.

The large cylindrical oil tank is mounted above the engine mount and is painted zinc chromate green.

In this closer view of the accessory case, the vacuum pump is visible. It is a black assembly with safety wired cover screws.

Leading to the accessory case are oil feed lines. The Y-shaped casting with gray hoses clamped to it takes oil from the tank above it and feeds the oil to the accessory case below.

The triangular black accessory is the oil separator that keeps oil out of the vacuum system.

The Curtiss propellor control relay box is mounted to one of the engine mount tubes, here seen covered in yellow masking tape.

The black cable is actually a wiring harness that carries wiring to the water injection control, carburetor air temperature control, and oil dilution control.

The R2800 is in place. It really makes the P-47 look even bigger than before it was mounted.

Test Fitting the cowling

The cowl adds to the unique visual impression that shouts Thunderbolt.

The air intake under the engine is also a very identifiable characteristic of the P-47.

Here is a time-lapse of the engine mounting process taken by Mark Adams in the restoration shop

The installation of the overhauled R-2800 brings P-47D-23RA 42-27609 ever closer to its first flight in 78 years. Everyone here at AirCorps Aviation is excited for that event, to say the least!

About the author

Chuck Cravens

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3 Responses

Tom Fey

February 27, 2022 at 6:40 am

Reply

Thank you for this and the numerous other updates on Aircorps projects. The quality and detail of the restorations is nicely matched by the outstanding photography and descriptive narrative found in the updates.
Chuck Cravens

February 28, 2022 at 10:14 pm

Reply

Thanks Tom, glad you enjoy the updates!
Yiorgos Karakasis

November 18, 2024 at 5:58 am

Reply

You re so much into the details so i have to notify that the interior of the cowling INCLUDING the air ducts on the “chin”,under the engine were a veruy matt silver

Here is a time-lapse of the engine mounting process taken by Mark Adams in the restoration shop

Chuck Cravens

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