Boolean issue

Hi All,

When i try to unify these 2 objects using the boolean modifier, it says unable to perform operation. Can anyone see why they will not unify??? (checked both meshes are manifold!).

Thanksengine_and-baseplate.blend (3.18 MB)

Both have double geometry but removing doubles from the baseplate and having the two intersect clearly, instead of overlapping surfaces, also the carve solver can execute.

Both have double geometry. Removing doubles creates non-manifold errors (overlapping edges).