This is the F-1 rocket engine used in the first stage of the Saturn V launch vehicle, which took astronauts to the Moon in the Project Apollo program. The first, or S-IC stage of the Saturn V, was fitted with five F-1's for a total lift-off thrust of 7.5 million pounds. The fully-fueled Saturn V weighed 6.1 million pounds.
The F-1 used RP-1, a type of kerosene, and liquid oxygen as the propellants. The F-1's 2,500 pound turbopump pumped in the propellants at 42,500 gallons per minute. The engine was regeneratively-cooled.
Gift of Rocketdyne Division, Rockwell International