XP-47H 42-23297 with Chrysler XIV-2220 experimental in-line engine
The XP-47H, undoubtedly the most unconventional-looking Thunderbolt, was created to test the 2,500 hp Chrysler 16-cylinder, inverted-vee, liquid-cooled XI-2220 engine. Two P-47D-15-RA airframes were taken from the Evansville factory for modification into the XP-47H. Intended solely as a flying test-bed, all armament and other military systems were removed. However, the conversion process proved more challenging than expected, with delays in the production of the Chrysler engine causing numerous setbacks. The XI-2220 was highly complex, necessitating significant structural modifications to fit it into the Thunderbolt airframe. The most noticeable change to the XP-47H was the addition of a large snout and intake for the cooling radiator.
Issues with the engine and its installation persisted for so long that the XP-47H did not take flight until July 1945. Although the original Chrysler design included an axial-flow supercharger, it could not be developed, so a General Electric CH-5 turbosupercharger was installed instead. Despite hopes for a top speed of 490 mph, the best speed the XP-47H could achieve was 414 mph. Consequently, the project was abandoned after consuming substantial funding.