recently ago I asked this question: Would like to understand the Animate function (calculation and stepping) and I got answered.
I tried to remove unnecessary code of jQ
I think what you want is https://github.com/jquery/jquery/blob/master/src/effects.js but with jquery you cant just pull out part of it and expect anything to work. There might be a way to custom build jquery but the effects library will have many other dependencies on jquery core etc to work.
Also relevant is https://stackoverflow.com/a/3143256/138883 which talks about creating custom builds