question: What engine was used in the aircraft intended to replace the F4F Wildcat?
answer: Pratt & Whitney R-2800 Double Wasp engine
context: Title: VMF-155
  Passage: Marine Fighting Squadron 155 (VMF-155) was a fighter squadron of the United States Marine Corps in World War II.  During the war, they flew the SBC Helldiver and, after reconstitution in 1943, the F4F Wildcat.  Later in the War the squadron also flew the F4U Corsair.  One of the squadron's pilots who went on to great distinction later in his career was Lieutenant John Glenn.  The squadron, also known as “Ready Teddy” was deactivated shortly after the war and is still inactive.
  Title: Grumman F6F Hellcat
  Passage: The Grumman F6F Hellcat is an American carrier-based fighter aircraft of World War II.  Designed to replace the earlier F4F Wildcat and to counter the Japanese Mitsubishi A6M Zero, it was the United States Navy's dominant fighter in the second half of the Pacific War.  The Hellcat competed with the faster Vought F4U Corsair for that role and prevailed, as the Corsair had significant issues with carrier landings.  The Corsair instead was primarily deployed to great effect in land-based use by the U.S. Marine Corps.
  Title: Brewster F2A Buffalo
  Passage: The Brewster F2A Buffalo was an American fighter aircraft which saw service early in World War II.  Designed and built by the Brewster Aeronautical Corporation, it was one of the first U.S. monoplanes with an arrestor hook and other modifications for aircraft carriers.  The Buffalo won a competition against the Grumman F4F Wildcat in 1939 to become the U.S. Navy's first monoplane fighter aircraft.  Although superior to the Grumman F3F biplane it replaced and the early F4Fs, the Buffalo was largely obsolete when the United States entered the war, being unstable and overweight, especially when compared to the Japanese Mitsubishi A6M Zero.
  Title: Republic P-47 Thunderbolt
  Passage: The Republic P-47 Thunderbolt was a World War II era fighter aircraft produced by the United States between 1941 and 1945.  Its primary armament was eight .50-caliber machine guns and in the fighter-bomber ground-attack role it could carry five-inch rockets or a bomb load of 2,500 pounds (1,103 kg).  When fully loaded the P-47 weighed up to eight tons (tonnes) making it one of the heaviest fighters of the war.  The P-47 was designed around the powerful Pratt & Whitney R-2800 Double Wasp engine which was also used by two U.S. Navy fighters, the Grumman F6F Hellcat and the Vought F4U Corsair.  The Thunderbolt was effective as a short-to-medium range escort fighter in high-altitude air-to-air combat and ground attack in both the World War II European and Pacific theaters.
citations: Republic P-47 Thunderbolt Grumman F6F Hellcat