Hi Alan I had exactly the same issue with the ST170 engine the VVT solenoid is really long and no matter what I do it fouls the under side of the bonnet.
I have tried different engine mounts to overcome the issue. Some people add vents and bonnet bulges but not doing that.
I will strip the VVT off the engine when I can be bothered. Bit of a step backwards really as the ECU I am using controlls the VTT.
It doesn't matter, the ST170 engine is a bit more rugged than the blacktop Zetec but had I known what I know now I would have just gone with a 2.0 black top like Danny.
Glad yours fitted ok