In 1943, Grumman produced two prototype Hellcats with the more powerful R-2800-34W engine, the same powerplant that was installed in the F4U-4 Corsair. Corky Meyer discussed these aircraft, briefly, in an article he wrote for Flight Journal magazine in their December, 1998 issue. He stated that their performance was comparable to that of the Corsair's. Some sources mention the top speed as being 417 mph.
The only picture I have ever seen of these aircraft appears to be either a modified late-model F6F-3 or an early production F6F-5, because both had the rear-view window behind the sliding canopy. The -3's air speed indicator caused Grumman a lot of grief with the Navy because it consistently read 20 knots slower than that of the F4U-1 Corsair, even when the two aircraft were in closely stabilised flight.
The -5 Hellcat had a redesigned air speed indicator which corrected this problem. My question is, does anyone know, for certain, which of the two models of Hellcat were used to produce these prototypes? If their performance was comparable to the F4U-4's, then the top speed should actually be close to 440 mph.
Assuming, of course, that the 417 mph top speed came from a reading of the earlier ASI of the -3 Hellcat. Adding 20 knots (23mph) to that speed puts it close to the 440 mph mark.
Also, does anyone know anything about the climb rate for these two aircraft? With a four blade propeller and and the upgraded engine, the climb rate should have been several hundred feet per minute faster than the F6F-5 Hellcat.
Appreciate any help you can give me.
