I h.p. Famous[1911-1917] and Titan[1914-1918] 1h.p. are the same, according to the 1918 IHC PARTS BOOK. The Titan jr was made 1915-1917. The Titan jr is lighter by about 100 lbs. than the 1 h.p. hopper-cooled Famous. The only parts they have in common[according to the parts cat.], are some nuts and bolts. Nice light, igniter fired IHC hopper-cooled engine.