Specifications

Where can you find the specifications and tolerances for a particular engine, in my case i'm looking for the specifications for a Audi S3 8P with a 2.0T FSI motor.

The factory Audi workshop manual will have all of the procedures and specifications for engine disassembly/reassembly. For popular engines these can usually be found via google. I just had a quick look myself and found several links that I'd suggest investigating.