Camshaft/Crackshaft position sensor

[Tarscien]

I'm currently in the process of rebuilding my head and I'm curious about the camshaft/crankshaft position sensor on it. How critical is it for this sensor to be attached in the exact same position as it was before the rebuild? If it is shifted around slightly how will this affect the tuning, if at all? I made sure to secure it so that the spinner wouldn't shift on me but would it affect anything if it got rotated 180 degrees? It's not keyed so I'm hoping that it won't hurt.
Thanks, Sandy

 

[pneumo]

The CAS should have a dot or a line on one of the wings that fit into the cam so that it doesn't get put on 180 degrees out of phase. The mark points toward the front of the car when the dowel pin on the cam is up.
Try to position the CAS in the middle of it's adjusting range. That will get it close enought to start the car, then you can get it timed properly once the engine is running.

 

[Tarscien]

Thanks, I found the dot. Can you give me any tips on tuning the engine? The bolts that were holding it place made nice little rust marks so I can put it on exactly where it was before... But how can I tell if that is the best place for it to be?

 

[pneumo]

The CAS is used to set ignition timing to 5 degrees BTDC. If it's turned clockwise timing will be advanced, turning it counterclockwise will retard timing.

Tuning the timing is a bit advanced. If the timing is set a few degrees higher it will boost power slightly, but if it's too high it could lead to frequent knock. Timing that is too low is very safe, but reduces power. Using really large fuel injectors has a side effect where the ECU gives up more advanced timing, so tuning the CAS to pull back a few degrees sometimes helps in this case.

Most importantly make small changes when tuning.