Setting base timing problem

[lukits01]

A few weeks ago I tried setting my base timing to 15deg advance

I lined the markers on the third white line after the orange(or red) line.

Is this correct?

at this time the CAS bolts was pretty much at the centre of its bracket

but for one reason or another my CAS died and now I have replaced it with another one sourced from a RB25DE

The thing is, with the new CAS, when I line up the bolts in the centre, the timing is way off. I adjusted it fully clockwise and I only manage to line up the markers with the 4th white line after the first orange one.

All this time I used the same kind of timing light, so Im pretty sure its not the light. Is it possible that the CAS from the two engines give different readings?

[BOOSTD]

the optical 360 degree mark inside the CAS may be in a different spot in relation to the keyway by the sound of it. Like you said installing back into the same spot should give identical readings. something deffinately sus.

[BHDave]

You've probably just installed the new cas one tooth out on the cam.

Just remove it and turn it back slightly and reinstall, then reset the base timing

[BOOSTD]

The CAS can't be installed wrong, it has a keyway that will only fit one way. It looks like a half circle.

[browny]

What engine do you have? RB25DET? (This is the forced induction forum)

The CAS is from an RB25DE right?

Are the part no.s the same on each CAS?