Over the past two years we have been following the restoration of an extremely rare ‘birdcage’ variant of the Vought F4U-1 Corsair (BuNo.02449) undergoing flight overhaul at Vultures Row Aviation in Cameron Park. , in California. A lot has happened since our last update in September, and we thought our readers would be interested in seeing photographs depicting the latest efforts.
Work continues on the middle section, which is progressing very well now as you can see in the images above, but of significant importance the aircraft’s Pratt & Whitney R-2800-8 Double Wasp engine recently performed his first tests on the test cell at Anderson Aeromotive in Grangeville, Idaho. The R-2800-8 was the first production model of the B-series of the Double Wasp and was produced in relatively small numbers (less than 4,000 units). The ‘Birdcage’ Corsairs used this early variant of the famous powertrain, which is now almost as rare as the aircraft itself. The earlier engine is very different from the much more available R-2800-8W that most later variants of the -1 Corsair used, with one main variation indicated by the suffix “W” which refers to water injection. To inhibit detonation at maximum power settings, a pilot could inject a water-methanol mixture into the engine, thus allowing better performance (for short bursts). Obviously, this was a desirable feature giving pilots an advantage over their opponents, so earlier engines without water injection were quickly rendered obsolete in wartime. As a result, the R-2800-8 is now a very rare engine, and it is likely that the example of Vultures Row will be among the first of its kind to power an aircraft soon after the end of WWII. As such, it will be a real treat to hear this engine run; it has a unique howl that you can appreciate in the videos further down on this page.
Vultures Row describes their efforts to resurrect this long-forgotten variant of the Double Wasp as follows: “It took years to acquire all the right parts for this unique engine. Lots of NOS [New Old Stock] parts… never operate cylinders that still have the original P&W paint on the base. [There are] also NOS internal clutch parts only used on this version and NOS baffles with original inspector and part number pads.
Commenting on the engine images above, Vultures Row also noted: Also notice the copper braided NOS spark plug wires and the priming system of the first version powered by a spider … not injected into the carburetor [but] rather injected into the cylinders directly. We also have an NOS [magneto] harness and made all new plates that attach to the fan section for clutches and other items. It’s as perfect in every way as it can get for an 80 year old engine. You will also notice that the unpainted mounting hardware on this engine has the old style silver colored CAD I cadmium plated finish that was typical of the era, rather than the gold colored CAD II finish more available than most fasteners. aviation grade wear these days. While this may seem like an insignificant detail, it gives the project extra authenticity, which Vultures Row is striving for. We are sure our readers will appreciate this endeavor.
The first operation of the engine appears in the rather blurry video below, captured inside the test cell. This is apparently the first time this engine has been running in 78 years!
The second revolution of the engine appears below. So far, the team has run the engine for about two hours, with another four hours without a problem before the engine is ready to ship. You’ll hear the distinct sound of this non-water-injected double wasp more clearly in this video, which also shows the motor note change when the operator engages the low speed setting on the two-stage compressor around the des mark. sixteen seconds… there is a unique type of howl, which is sure to interest the air show audience!