10SI Alternator Conversions Tech Session(Part of the series: "More than you ever wanted to know")

By Tim Palmer and Gary Baxter

This article comes from the recent successful (after a fashion) club tech session on converting a late model to an internal alternator (10SI). This procedure has been pretty thoroughly documented in various Corvair publications. We did pick up a few things along the way.

  1. Make sure you get the right alternator! The guys at the parts counters don’t know parts any more. They just know what’s on the computer screen. You can find a ton of information on the 10SI and it’s wiring at http://www.madelectrical.com/electricaltech/delcoremy.shtml
  2. An impact wrench makes it easy to remove the fan nut. This is a conventional right hand nut (unlike a real Corvair generator).
  3. When you swap the fan make sure the nut is tight. The fan isn’t keyed to the shaft like the generators so the nut has to be tight.
  4. You may need to use the fan nut from new 10SI alternator to get the nut fully threaded to the shaft. It’s usually self-locking. The original Corvair had a lock washer and nut.
  5. You can use the existing wires to the alternator by using a small screwdriver to remove the wires from the existing plastic connector and transfer them to the new connector. This trick doesn’t work on early models since they use ring terminals.
  6. When you put the alternator back together you should clock it such that the rear bracket attaching bolt is pointing up. This will have the electrical plug connector pointing toward the front of the car. This is so the newly made rear bracket will provide the maximum support. Leaving the bracket off WILL lead to failure of the alternator front mounts or the oil filter/ alternator adapter ears.
  7. Check your ground wires. There should be a big cable from the battery to the engine for the starter and ignition. There should also be a big wire or cable from the battery to the body for everything except the starter and ignition.
  8. Conversion kits are available from the various Corvair vendors.