I have just finished making modifications to my saph to make it stage 3. I have it running, but when i blip the throttle, i sometimes hear a sound like a mechanical wrattle. It is coming from around the turbo area, but i have removed the filter hose to check for play in the shaft, but it seems ok. There is minimal radial play, and no axial play at all. Is it possible for the turbo bearings to have failed, but still have very minimal play? Also, the amal valve is clicking when the revs increase, could this be faulty also?

The chip is an MSD, running an L8 bought secondhand, the turbo a t34 again bought secondhand.

Any help much appreciated, cheers.