Does Raymer's installed engine equation include the weight of the pylon? I am currently modelling an aero engine and require the weight breakdown of the individual components, I have the dry weight of the engine and need to verify the pylon and nacelle weight.

Raymer has presented an equation for the weight of the installed engine in his book 
$$W_{InstalledEngine} = 2.575 *(W_{Engine})^{0.922}*N_{engine}$$

Does this include the pylon?
No, it doesn't include the pylon. If you think about it, the engine is installed on the pylon, which is part of the aircraft's fuselage or wing structure and not part of the engine. 

You can see what I mean by watching this video of the replacement of an engine on an American Airlines 777.

Raymer's equation does include the nacelle and other auxiliary equipment installed on the engine.