The Merlin Engine : The Engine That Won World War II May 13, 2018 Unipro2013main Military History, WW2 Rolls Royce Merlin With 1390 hp, Jay demonstrates the power and engineering of the Merlin 1650-1 engine that was the heart of the P-51 Mustangs and the Lancaster bombers in World War II. Please support our Sponsors - Or Buy an Item from our Catalog