Aluminum Generator or Alternator Pulley

One piece machined pulley for Cooper S and Sprite & Midget dynamos/alternators. The original dynamo pulleys were 2 piece metal tin pulley held by rivets to a boss but it was found they were not up to the job on Cooper S and other engines such as Sprites and Midgets. Many different sizes seem to have been used from 2.75" cast one piece pulley to 3.25" and leyland ST also made a 5" wide type to lower the dynamo revs on race cars. These have a keyway slot and fit a 15mm shaft whereas later alternators used a 17mm shaft without keyway slot.