51 Hours is an unreleased single by Diamond and Pearl planned for release in Summer 1992 after the Diamonds And Pearls Tour. The song was played on a Spanish radio station during the Summer of 1992. It would have been the first song released by Diamond and Pearl as 'solo' artists and vocalists.
Around 20 copies of an in-house 12" vinyl were pressed, containing a longer version of the track on both sides, but the copies were not officially distributed. It is not known which song would have been included as the b-side.
Both the single and the track remain unreleased.