ok, got your email.
I use lightwave 8 and this is what I did

1. there was a group of polygons that 'capped' the intake of your motor, deleted those.
2. merge points - which reconnects all polys and removes duplicate points . 
3. unify polygons - removes any polys in the same places 400+ poly eliminated
4. selected and did an align , if needed flip , to get all polys facing out.
5. deleted an inner 'plate' and two rings of polys at the motor exhaust.
        I rebuilt that part by selecting the bottom ring of points, create a polygon , and then doing two bevels to build the exhaust .
6. rebuilt the rotor vanes to add thickness .
      - moved them to new layer
      - deleted all but 1 blade
     -  extruded it for thickness - very small amount
     - radial array - 16 copies around center point
      - moved back to original layer

mirrored the left motor to make the right motor.
saved both as obj files
tried to preserve the uv mapping - not sure its correct though.

emailed back to you as a zip file .

Lightwave uses layers to isolate parts of the model to make working easier.

Took maybe 10-15 minutes to do once I had messed up a few times ... it was late :)

Unsolicited comment:
you seem to have 36 points on your circles, which is ok. BUT
your total polygon count will be lower if you go to 24 or even 16 sides.
Poser smoothing will make it look good.
Its worth trying a few tests to see the result if you are modelling for poser.
Its a compromise though because the edges may start to show in the shadows.