I just recently purchased someone else's RB 240z conversion (Danger Will Robison!). Before I installed the engine in the car, I wanted to start the engine as it's been sitting for seven years. This engine would not start up and just kept backfiring. After verifying the Cam timing for the seventh time and checking CAS output signals. I could not find an FSM reference which way to orientate the CAS disk, so for fun. I just flipped the CAS disk over to give it a try. The engine fired up and ran like a champ. Problem solved!
Here are a couple pictures showing the correct orientation for a RB25det NEO Series 2 engine set at 15 Degrees BTDC. I hope this saves someone else hours of troubleshooting!