Given an engine number, where can I find out its specification?

Any pointer or web that have such information for a WRX/STi engine would be great.

Help pleaseeee.

Thanks in advance.

you talking about the VIN number? if so look here
http://www.ravensblade-impreza.com/techdocs/pdf/misc/vin.pdf

Thanks very much ldelaysionl for your pointer, the information
on that file is also great. But, what I am looking for is based on
"engine number", not the number stamped on the body of the car.

My situation is that I have bought an engine which supposed to
be a STi engine, but since it is second hand from Japan, what I can
see is only the engine itself. So, I just wondering if I can find
specification (for example, horse power, etc) from the number
appearred on the engine alone.