I had issues making the panel lines and finally found a way to make them, in the photo it can be seen that only the rear cowling line is made, still some work to do such as modify the pylon and the outer ring.
The white thicker line is actually putty from having assembled both halves from a previous cast.
I am hoping to cast the engine in one single piece as seen in the photo (exhaust to be attached separately) in order to avoid problems when assembling both halves as this engine is quite round.